Category Archives: Insects

Cicadas, or how I Am Such A Scientist, or a demonstration of good editing

Charles Q. Choi runs a bi-weekly series on the Guest Blog over at Scienctific American – Too Hard for Science? In these posts, he asks scientists about experiments that cannot be or should not be done, for a variety of reasons, though it would be fun and informative it such experiments could get done.

For one of his posts, he interviewed me. What I came up with, inspired by the emergence of periodic cicadas in my neighborhood, was a traditional circadian experiment applied to a much longer cycle of 13 or 17 years.

Fortunetaly for me, Charles is a good editor. He took my long rant and turned it into a really nice blog post. Read his elegant version here – Too Hard for Science? Bora Zivkovic–Centuries to Solve the Secrets of Cicadas.

Now compare that to the original text I sent him, posted right here:

The scientist: Bora Zivkovic, Blog Editor at Scientific American and a chronobiologist.

The idea: Everything in living organisms cycles. Some processes repeat in miliseconds, others in seconds, minutes or hours, yet others in days, months or years. Biological cycles that are most studied and best understood by science are those that repeat approximately once a day – circadian rhythms.

One of the reasons why daily rhythms are best understood is that pioneers of the field came up with a metaphor of the ‘biological clock‘ which, in turn, prompted them to adapt oscillator theory (the stuff you learned in school about the pendulum) from physics to biology.

And while the clock metaphor sometimes breaks down, it has been a surprisingly useful and powerful idea in this line of research. Circadian researchers came up with all sorts of experimental protocols to study how daily rhythms get entrained (synchronized) to the environmental cycles (usually light-dark cycles of day and night), and how organisms use their internal clocks to measure other relevant environmental parameters, especially the changes in daylength (photoperiod) – information they use to precisely measure the time of year and thus migrate, molt or mate during an appropriate season.

These kinds of experiments – for example building Phase-Response Curves to a variety of environmental cues, or a variety of tests for photoperiodism (night-break protocol, skeleton photoperiods, resonance cycles, T-cycles, Nanda-Hamner protocol etc.) – take a long time to perform.

Each data point requires several weeks: measuring period and phase of the oscillation before and after the pulse (or a series of pulses) of an environmental cue in order to see how application of that cue at a particular phase of the cycle affects the biological rhythm (or the outcome of measuring daylength, e.g., reproductive response). It requires many data points, gathered from many individual organisms.

And all along the organisms need to be kept in constant conditions: not even the slightest fluctuations in light (usually constant darkness), temperature, air pressure, etc. are allowed.

It is not surprising that these kinds of experiments, though sometimes applied to shorter cycles (e.g., miliseconds-long brain cycles), are rarely applied to biological rhythms that are longer than a day, e.g., rhythms that evolved as adaptations to tidal, lunar and annual environmental cycles. It would take longer to do than a usual, five-year period of a grant, and some experiments may last an entire researcher’s career. Which is one of the reasons we know so little about these biological rhythms.

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Living out in the country, in the South, just outside Chapel Hill, NC, every day I open the door I hear the deafening and ominous-sounding noise (often described as “horror movie soundtrack) coming from the woods surrounding the neighborhood. The cicadas have emerged! The 13-year periodic cicadas, that is. Brood XIX.

I was not paying attention ahead of time, so I did not know they were slated to appear this year in my neck of the woods. One morning last week, I saw a cicada on the back porch and noticed red eyes! A rule of thumb that is easy to remember: green eyes = annual cicadas, red eyes = periodic cicadas. I got excited! I was waiting for this all my life!

Fortunately, once they emerge, cicadas are out for a few weeks, so my busy travel schedule did not prevent me from going to find them (just follow the sound) to take a few pictures and short videos.

There are three species of periodic cicadas that emerge every 17 years – Magicicada septendecim, Magicicada cassini and Magicicada septendecula. Each of these species has a ‘sister species’ that emerges every 13 years: M.tredecim, M. tredecassini and M.tredecula. A newer species split produced another 13-year species: Magicicada neotredecim. The species differ in morphology and color, while the 13 and 17-year pairs of sister species are essentially indistinguishable from each other. M.tredecim and M.neotredecim, since they appear at the same time and place, differ in the pitch of their songs: M.neotredecim sings a higher tone.

So, how do they count to 13 or 17?

While under ground, they undergo metamorphosis four times and thus go through five larval instars. The 13 and 17-year cicadas only differ in the duration of the fifth instar. They emerge simultaneously, live as adults for a few weeks, climb up the trees, sing, mate, lay eggs and die.

When the eggs hatch, the newly emerged larvae fall from the trees to the ground, dig themselves deeper down, latch onto the tree roots to feed on the sap, and wait another 13 or 17 years to emerge again.

There are a number of hypotheses (and speculations) why periodic cicadas emerge every 13 or 17 years, including some that home in on the fact that these two numbers are prime numbers (pdf).

Perhaps that is a way to fool predators which cannot evolve the same periodicity (but predators are there anyway, and will gladly gorge on these defenseless insects when they appear, whenever that is, even though it may not be so good for them). Perhaps this is a speciation mechanism, lowering the risk of hybridization between recently split sister species?

Or perhaps that is all just crude adaptationist thinking and the strangeness of the prime-number cycles is in the eye of the beholder – the humans! After all, if an insect shows up every year, it is not very exciting. Numerous species of annual cicadas do that every year and it seems to be a perfectly adaptive strategy for them. But if an insect, especially one that is so large, noisy and numerous, shows up very rarely, this is an event that will get your attention.

Perhaps our fascination with them is due to their geographic distribution. Annual cicadas may also have very long developmental times, but all of their broods are in one place, thus the insects show up every year. In periodic cicadas, different broods appear in different parts of the country, which makes their appearance rare and unusual in each geographic spot.

In any case, I am more interested in the precision of their timing than in potential adaptive explanations for it. How do they get to be so exact? Is this just a by-product of their developmental biology? Is 13 or 17 years just a simple addition of the duration of five larval stages?

Or should we consider this cycle to be an output of a “clock” (or “calendar”) of sorts? Or perhaps a result of interactions between two or more biological timepieces, similarly to photoperiodism? In which case, we should use the experimental protocols from circadian research and apply them to cicada cycles.

Finally, it is possible that a ling developmental cycle is driven by one timing mechanism, but the synchronization of emergence in the last year is driven by another, perhaps some kind of clock that may be sensitive to sound made by other insects of the same species as they start digging their way up to the surface.
The problem: In order to apply the standard experiments (like construction of a Phase-Response Curve, or T-cycles), we need to bring the cicadas into the lab. And that is really difficult to do. Husbandry has been a big problem for research on these insect, which is why almost all of it was done out in the field.

When kept in the lab, the only way to feed them is to provide them with the trees so they can drink the sap from the roots. This makes it impossible to keep them in constant conditions – trees require light and will have their own rhythms that the cicadas can potentially pick up, as timing cues, from the sap. So, the first thing we need to do is figure out a way to feed them artificially, without reliance on living trees for food.

Also, we do not know which environmental cues are relevant. Is it light cycle? Photoperiod? Or something cycling in the tree-sap? Or temperature cycles? What are the roles of developmental hormones like Juvenile Hormone or Ecdysone? We would have to test all of them simultaneously, hoping that at least one of them turns out to be the correct one.

Second, more obvious problem, is time. These experiments would last hundreds of years, perhaps thousands! Some experiments rely on outcomes of previous experiments for the proper design. Who would do them? What funding agency would finance them? Why would anyone start such experiments while knowing full well that the results would not be known within one’s lifetime? Isn’t this too tantalizing for a scientist’s curiosity?

The solution? One obvious solution is to figure out ways to get to the same answers in shorter time-frames. Perhaps by sequencing the genome and figuring out what each gene does (perhaps by looking at equivalents in other species, like fruitflies, or inserting them into Drosophila and observing their effects), hoping to find out the way timing is regulated. This will probably not answer all our questions, but may be good enough.

Another way is to set aside space and funding for such experiments and place them into an unusual administrative framework – a longitudinal study guided by an organization, not a single researcher getting a grant to do this in his or her lab. This way the work will probably get done, and the papers will get published somewhere around 2835 A.D.

~~~~

See? How long and complex my text is? Now go back to the post by Charles to see again how nicely he edited the story.

Cicadas, Brood XIX, northern Chatham Co, NC [Videos]



Sigma Xi Pizza Lunch (if you have stomach to eat at the time): Everything you wanted to know about Bedbugs but were too afraid to ask

You’ve heard the media buzz about bed bugs. But what of the science? Join us at noon, Jan. 25 here at Sigma Xi to hear N.C. State University entomologist Coby Schal offer the facts. He’ll discuss the basic biology of the insects and some of the new research strategies aimed at finding ways to better control them.

Thanks to a grant from the N.C. Biotechnology Center, American Scientist Pizza Lunch is free and open to science journalists and science communicators of all stripes. Feel free to forward this message to anyone who might want to attend. RSVPs are required (for the slice count) to cclabby@amsci.org

Directions to Sigma Xi, the Scientific Research Society in RTP, are here.

Insects! Outreach and Three Books (video)

From Joanne Manaster:

Joanne shares information about the University of Illinois’ outreach, BugScope and tells of a yearly event featuring insects called The Insect Fear Film Festival. Awesome! Also, three Featured Books by Sonia Dourlot (Insect Museum), Hugh Raffles (Insectopedia) and May Berenbaum (The Earwig’s Tale) All three books have chapters listed in alphabetical order, but not in the way you would imagine

Look Up! The Billion-Bug Highway You Can’t See (video)

Bed bugs and cockroaches: The insects that bug us

Our August Science Café (description below) will be held on Tuesday 8/17 at Tir Na Nog on S. Blount Street.

Just in time to lead up to BugFest the museum’s annual event highlighting the world of arthropods, our café this month will be a discussion about insects (in particular, some species that we are not too fond of… bed bugs and cockroaches!)

I first learned about bed bugs from a television documentary probably a year or more ago. Since that show, and most likely because I work in a natural history museum, I have heard more and more about these pests and how difficult they are to deal with. Because travelers can bring them home in suitcases after staying in infested hotel rooms, it is important for all of us to understand their life history. An interesting website http://bedbugregistry.com/, is a site where the public report bed bugs that they have encountered in hotels and apartments. You can see from the listings that these pests are found throughout our country.

Another pest that people are more familiar with, the cockroach, (found in all 50 states) is also very difficult to deal with — So, we’ve added them to the line up for our evening’s café discussion. Learn how to distinguish one species of roach from another and how to be on the lookout for these unwanted house (or office) guests.

Bed bugs and cockroaches: The insects that bug us

Tuesday, August 17, 2010

6:30-8:30 p.m. with discussion beginning at 7:00 followed by Q&A

Tir Na Nog, 218 South Blount Street, Raleigh, 833-7795

After disappearing from many countries for almost 50 years, bed bugs have made a comeback and are once again sucking our blood while we sleep and stowing away in our luggage when we travel. Cockroaches, on the other hand, have always been a fact of life for people living in the South, but all roaches are not the same — some are part of our outdoor environment and only end up in our homes by accident, while others are only found in buildings and produce allergens that can pose health risks.

In this Science Café, we will explore some of the urban legends related to bed bugs, observe some insects to get an idea of what to watch out for, and discuss how you can keep these tiny vampires out of your home. We will also discuss do-it-yourself options for cockroach control as well as give you some cockroach identification tips.

About Our Speaker: Richard Santangelo is a research specialist in the Entomology Department at North Carolina State University. His work focuses on urban pest control aspects of entomology, including pesticide resistance monitoring of cockroaches and bed bugs, product testing of commercial insecticides for pest control, and allergen intervention in low income housing and hog farms. Santangelo has also worked on a Colorado Spider Survey with the Denver Museum of Nature and Science and biological control of cotton pests in Arizona.

What bug is this?

A reader sent me this picture, asking for an ID – it was taken in upstate New York:
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Breakfast with a side of Science – What’s Bugging You? Animals We Love to Hate

At the NC Museum of Natural Sciences:

What’s Bugging You? Animals We Love to Hate
Wednesday, September 30, 2009
8:00 – 10:00 am with discussion beginning at 9:00 followed by Q&A
Location: The Acro Cafe – 4th Floor of the Museum of Natural Sciences
Fire ants. Mosquitoes. Flies. Ticks. Gnats. Bed Bugs. The list goes on and on.
They disturb our sleep, sting us, envenomate us, suck our blood, eat our food, crawl on us…yet at the same time, they pollinate our food and flowers, provide insect control, and increase biodiversity. So, what is a pest? Are some of these pests invasive species? What can or should be done about them?
About the Speaker:
Join Dr.Colin Brammer, Entomologist and Curator of the Museum’s Naturalist Center for a discussion on all things pest related in our next Breakfast with a Side of Science

The World Science podcast/forum: May Berenbaum – DDT vs. Malaria: The Lesser of Two Evils?

The World is a radio show co-produced by WGBH Boston, Public Radio International and BBC. You can probably hear it on your local NPR station – if not, you can find all the shows recorded on the website.
You may remember that I went to Boston a few months ago, as a part of a team of people helping the show do something special: use the NSF grant they recently received to expand their science coverage and, in collaboration with Sigma Xi and NOVA, tie their radio science coverage to their online offerings.
The result is The World: Science website, a series of weekly science podcasts with Elsa Youngsteadt and David Kohn (subscribe to the RSS feed) and, starting this week, something new.
First, the radio show will have a brief segment on a science topic that includes an interview with a science-related person. A longer version of that story/interview will be on the website as a podcast, with additional links to outside sources. And, most exciting, the person who was interviewed for the show will come by the online forum for a week after the show and answer readers/listeners’ questions. Like an online version of a Science Cafe.
Today, the guest will be entomologist May Berenbaum. In the podcast and in the forum she will address the DDT debate: Is it really as bad as the critics say? (Even Rachel Carson thought it had value.) Is it really as good as the proponents say? (Sure, it may help with malaria control for a while, but eventually the mosquitoes will develop resistance.) Here’s an op/ed May had in the Washington Post a few years ago: If Malaria’s the Problem, DDT’s Not the Only Answer.
So, listen to the podcast and join the conversation which has already started and will be ongoing until next Friday. We hope that, with all of you checking in and spreading the word, the discussion will grow.
You should also follow the news about this endeavor on Twitter, in the FriendFeed room and a Facebook page. Join, friend, follow, subscribe. And come back next week and next and next. And don’t feel shy to give feedback as this is just in the early stages of development and we are open to suggestions.

The Butterfly House on the island of Mainau

A couple of German bloggers and I went to see the Butterfly House on the Island of Mainau. They had good cameras with lenses that allowed them to take extreme close-ups. I had to do with a little pocket camera, but a few pictures turned out decent enough to show:

Continue reading

Name this Bug!

I am pretty sure it’s a true bug (i.e., I am not being sloppy by calling just any ole’ insect a bug). I got as close as I could with my iPhone, but the lighting was bad. This is on my porch and the bug is really large – about 1 inch in length of the body.
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So, what is it?

Why social insects do not suffer from ill effects of rotating and night shift work?

ResearchBlogging.orgMost people are aware that social insects, like honeybees, have three “sexes”: queens, drones and workers.
Drones are males. Their only job is to fly out and mate with the queen after which they drop dead.
Female larvae fed ‘royal jelly’ emerge as queens. After mating, the young queen takes a bunch of workers with her and sets up a new colony. She lives much longer than other bees and spends her life laying gazillions of eggs continuously around the clock, while being fed by workers.
Female larvae not fed the ‘royal jelly’ emerge as workers.
Workers perform a variety of jobs in the hive. Some are hive-cleaners, some are ‘nurses’ (they feed the larvae), some are queen’s chaperones (they feed the queen), some are guards (they defend the hive and attack potential enemies) and some are foragers (they collect nectar and pollen from flowers and bring it back to the hive).
What most people are not aware of, though, is that there is a regular progression of ‘jobs’ that each worker bee goes through. The workers rotate through the jobs in an orderly fashion. They all start out doing generalized jobs, e.g., cleaning the hive. Then they move up to doing a more specialized job, for instance being a nurse or taking care of the queen. Later, they become guards, and in the end, when they are older, they become foragers – the terminal phase.
This pattern of behavioral development is called “age polyethism” (poly = many, ethism = expression of behavior), or sometimes “temporal polyethism” (image from BeeSpotter):
Age polyethism.jpg
This developmental progression in behavior is accompanied by changes in brain structure, patterns of neurotransmitter and hormone synthesis and secretion, and patterns of gene expression in the central nervous system.
Some years ago (as in “more than ten years ago”) Gene Robinson and his students started looking at daily patterns of activity in honeybees. The workers in their early stages are doing jobs inside the hive, where it is always dark. They clean the hive, take care of the eggs and pupae, and feed the larvae and the queen around the clock. Each individual bee sometimes works and sometimes sleeps, without any semblance of a 24-hour pattern. Different individuals work and sleep at different, apparently random times. The hive as a whole is thus constantly busy – there is always a large subset of workers performing their duties, day and night.
As they get older, they start doing the jobs, like being guards, that expose them to the outside of the hive, thus to the light-dark and temperature cycles of the outside world.
Finally, the foragers only go out during the daytime and have clear and distinct daily rhythms. Furthermore, the foragers have to consult an internal clock in order to orient towards the Sun in their travels, as well as to be able to communicate the distance and location of flowers to their mates in the hive using the ‘waggle dance’. As bees are social insects, it is difficult to keep individuals in isolation for longer periods of time, but it has been done successfully and, in such studies, foragers exhibit both freerunning (in constant darkness) and entrained (in light-dark cycles) circadian rhythms, while younger workers do not.
In the Robinson lab, then PhD student Dan Toma and postdoc Guy Bloch did much of the early and exciting work on figuring out how the rhythmicity develops in individual worker bees as they pass through the procession of ‘jobs’.
In an early study, they measured levels of expression of mRNA of the core clock gene Period (Per). The gene was expressed at low levels and no visible daily rhythm in early-stage workers, but at much higher levels and in a circadian fashion in foragers.
As the levels of expression were measured crudely – in entire bee brains – it was impossible at the time to be sure which of the two potential mechanisms were operating: 1) the celluular clock did not work until the bee became a forager, or 2) the cellular clocks were working, but different cells were not synchronized with each other, producing a collectively arrhythmic output: both as measured by gene expression of the entire brain and as measured by behavior of the live bee.
Either way, the study showed correlation: the appearance of the functional circadian clock coincided with other changes in the brain structure, brain chemistry and bee behavior. They could not say at the time what causes what, or even if the syncronicity of changes was purely coincidental. They needed to go beyond correlation and for that they needed to experimentally change the timing to see if various processes can be dissociated or if they are tightly bound to each other.
And there is a clever way to do this! First, they took some hives and removed all the foragers from it. This disrupted the harmony of the division of labor in the hive – too many cleaners and nurses, but nobody is bring the food home. When that happens, the behavioral development of other workers speeds up dramatically – in no time, some nurses and guards develop into foragers. And, lo and behold, the moment they became foragers, they developed rhythms in behavior and rhythms of the Per gene expression in the brain. So, as the development is accelerated, everything about it is accelerated at the same rate: gene expression, brain structure, neurochemistry, and behavioral rhythmicity.
Nice, but then they did something even better. They removed most of the cleaners and nurses from some hives. Again, the balance of the division of labor was disrupted – plenty of food is arriving into the hive but there is not enough bees inside to take care of that food, process it, feed the larvae, etc. What happened then? Well, some of the foragers went back into the hive and started performing the house-keeping duties instead of flying out and about. And, interestingly, their brain structure and chemistry reverted its development to resemble that of cleaners and nurses. They lost behavioral rhythmicity and started working randomly around the clock. And the rhythm of clock-gene expression disappeared as well.
So, genetic, neural, endocrine, circadian and behavioral changes all go together at all times. Social structure of the colony, through the patterns of pheromones present in the hive, affects the gene expression, brain development and function, and behavior of individual bees. Just like the gene expression and behavioral patterns, the patterns of melatonin synthesis and secretion in honeybee brains is low and arrhythmic in young workers and becomes greater and rhythmic in foragers. With the recent sequencing of the honeybee genome, the potential for future research in honeybee chronobiology looks promising and exciting.
But are these findings generalizable or are they specific to honeybees? How about other species of bees or other social insects, like wasps, ants and termites? Are they the same?
Other species of socials insects have been studied in terms of age polyethism as well. The earliest study I am aware of (let me know if there is an older one) studying behavioral rhytmicity in relation to behavioral development was a 2004 Naturwissenschaften paper by Sharma et al. on harvester ants. In that study, different castes of worker ants exhibited different patterns – some were strongly diurnal, some nocturnal, some had strange shifts in period, and some were arrhythmic. Those with rhythms could entrain to light-dark cycles as well as display freerunning rhythms in constant darkness.
Just last month, a new paper on harvester ants came out in BMC Ecology (Open Access). In it, Ingram et al. show that foragers have circadian rhythms (both in constant darkness and entrained to LD cycles) in expression of Period gene (as well as behavioral rhythms), while ants working on tasks inside the hive do not exhibit any rhythms either in clock-gene expression or in behavior, suggesting that the connection between age polyethism and the development of the circadian clock may be a universal property of all social insects.
We know that in humans, night-shift and rotating-shift schedules are bad for health as the body is in the perpetual state of jet-lag: the numerous clocks in our bodies are not synchronized with each other. We have evolved to be diurnal animals, entrained to environmental light cycles and not traveling over many time zones within hours, or working around the clock. Social insects have evolved a different strategy to deal with the potentially ill effects of shift-work: switch off the clock entirely until one develops far enough that time-keeping becomes a requirement.
Yang, L., Qin, Y., Li, X., Song, D., & Qi, M. (2007). Brain melatonin content and polyethism in adult workers of Apis mellifera and Apis cerana (Hym., Apidae) Journal of Applied Entomology, 131 (9-10), 734-739 DOI: 10.1111/j.1439-0418.2007.01229.x
Sharma, V., Lone, S., Goel, A., & Chandrashekaran, M. (2004). Circadian consequences of social organization in the ant species Camponotus compressus Naturwissenschaften, 91 (8) DOI: 10.1007/s00114-004-0544-6
Ingram, K., Krummey, S., & LeRoux, M. (2009). Expression patterns of a circadian clock gene are associated with age-related polyethism in harvester ants, Pogonomyrmex occidentalis BMC Ecology, 9 (1) DOI: 10.1186/1472-6785-9-7

The Good, The Bad and The Ugly: Exploring the ecology of insects (video)

Meetings I’d like to go to….Part V

Genetic Manipulation of Pest Species: Ecological and Social Challenges:

In the past 10 years major advances have been made in our ability to build transgenic pest strains that are conditionally sterile, harbor selfish genetic elements, and express anti-pathogen genes. Strategies are being developed that involve release into the environment of transgenic pest strains with such characteristics. These releases could provide more environmentally benign pest management and save endangered species, but steps must be taken to insure that this is the case and that there are no significant health or environmental risks associated with releases. Our conference will foster discussion of risks and benefits of these technologies among scientists, policy makers, and citizens.

March 4-6, 2009
North Carolina State University, Raleigh, NC
This is very soon – I’ll try to go to some of it if I can….

Making an Emerging Cage (video)

From Mimi.

This is your honeybee. And this is your honeybee on drugs.

A well-written press release on a very well done and exciting study:
Honey bees on cocaine dance more, changing ideas about the insect brain:

In a study published in 2007, Robinson and his colleagues reported that treatment with octopamine caused foraging honey bees to dance more often. This indicated that octopamine played a role in honey bee dance behavior. It also suggested a framework for understanding the evolution of altruistic behavior, Robinson said.
“The idea behind that study was that maybe this mechanism that structures selfish behavior – eating – was co-opted during social evolution to structure social behavior – that is, altruistic behavior,” he said. “So if you’re selfish and you’re jacked up on octopamine, you eat more, but if you’re altruistic you don’t eat more but you tell others about it so they can also eat.”
But it was not even known if insects have a bona fide reward system. That question led the researchers to study the effects of cocaine on honey bee behavior. Cocaine – a chemical used by the coca plant to defend itself from leaf-eating insects – interferes with octopamine transit in insect brains and has undeniable effects on reward systems in mammals, including humans. It does this by influencing the chemically related dopamine system.
Dopamine plays a role in the human ability to predict and respond to pleasure or reward. It is also important to motor function and modulates many other functions, including cognition, sleep, mood, attention and learning.
One aspect of reward in the human brain involves altruistic behavior, Robinson said. Thinking about or performing an altruistic act has been found to excite the pleasure centers of the human brain.
“There are various lines of thought that indicate that one way of structuring society is to have altruistic behavior be pleasurable,” he said.
Because cocaine causes honey bees to dance more – an altruistic behavior – the researchers believe their results support the idea that there is a reward system in the insect brain, something that has never before been shown.

To determine whether the cocaine was merely causing the bees to move more or to dance at inappropriate times or places, the researchers conducted a second set of experiments. These tests showed that non-foraging honey bees don’t dance, even when exposed to cocaine. They showed that foragers on cocaine do not move more than other bees (except when dancing), and that they do not dance at inappropriate times or in locations other than the dance floor.
The researchers also found that the bees on cocaine do not dance every time they go on a foraging excursion. And, most important, their dances are not distorted.
“It’s not like they’re gyrating wildly on the dance floor out of control,” Robinson said. “This is a patterned response. It gives distance information, location information. That information is intact.”
In a final experiment that also shows parallels to human behavior, the researchers found that honey bees on cocaine experience withdrawal symptoms when the drug is withheld.
“This study provides strong support for the idea that bees have a reward system, that it’s been co-opted and it’s now involved in a social behavior, which motivates them to tell their hive mates about the food that they’ve found,” Robinson said.

Read the whole thing….

What insect is this?

This insect has been sitting on my window, completely motionless, all day. It is about 2in long in the body, probably around 5-6in if one includes the stretched legs. What is this? Does it sting or can I handle it safely, put it on a sheet of white paper to take a better picture?
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iNaturalist rocks!

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Thanks Bill for drawing my attention to iNaturalist which has the makings of an awesome site!
What is it?
It is essentially a Google Map where people can add pins every time they see an interesting critter: a plant, fungus, animal, etc. What is recorded is geographical coordinates and time when it was posted.
Moreover, people can link from the pins to pictures of the sighted critters if they upload them on Flickr (nice way to interlink existing social networking sites instead of reinventing the wheel). And they can put additional information, e.g., description of the habitat where they saw the creature. They can try to identify it and others can chime in agreeing or disagreeing on the ID. One can also view maps in various ways – by time, by broader groups (e.g., insects, birds…), or by the degree of agreement people have about the ID.
The site has, apparently, just started, thus the number of people and the number of sightings is still relatively small and limited to mainly a couple of geographic locations (mostly California and Washington state).
But, imagine a couple of years from now, with millions of people pinning millions of sightings, providing additional information and then having the community agree on the ID? How about ecologists putting in all their field survey data (at least after publication if not before)? How about everyone who participates in the Christmas bird hunt? What an incredible database that will be! Something that one can search with machines, build and test models, and use the results to test ideas about, for instance, effects of weather events (hurricanes, fires, floods, El Nino, etc.) or broader weather changes (e.g., Global Warming).
In order for this database to become useful, I hope that the developers, as soon as possible, make sure it is possible for all the info to be machine searchable. And also to provide, perhaps, various fields that will lure people to put in more information. Right now, there is a date when the pin is posted, but the date of actual sighting is much more important. Exact latitude and longitude. Perhaps altitude. Perhaps depth for aquatic organisms. Exact time of day of the sighting. Description of the habitat. Number of individuals. Measurements of different kinds (one often cannot infer from pictures if the critter is 3cm or 30cm long, for instance). Behavioral observations. And of course the ID.
Such a database would be biased of course. People will tend to record when they see something unusual, or cool, or charismatic megafauna, rather than grass or field of corn or a bunch of squirrels in a tree. Also, more critters will be found in urban areas, on farms, in parks and by the roadsides than in places where one needs climbing (or diving) gear, or an hour of work with a machete in order to get to the habitat. But ecological models using the database could be made to account for these biases anyway.
In any case, I urge you to bookmark this site, and to use it. And let’s see how it shapes up over time.

Clocks and Migratory Orientation in Monarch Butterflies

Blogging on Peer-Reviewed Research

I had no time to read this in detail and write a really decent overview here, perhaps I will do it later, but for now, here are the links and key excerpts from a pair of exciting new papers in PLoS Biology and PLoS ONE, which describe the patterns of expression of a second type of cryptochrome gene in Monarch butterflies.
This cryptochrome (Cry) is more similar to the vertebrate Cry than the insect Cry, also present in this butterfly. The temporal and spatial patterns of expression of the two types of Cry suggest that they may be involved in the transfer of time-information from the circadian clock to the brain center involved in spatial orientation during long-distance migration.
The PLoS Biology paper looks at these patterns of expression, while the PLoS ONE paper identifies a whole host of genes potentially implicated in migratory behavior, including the Cry2. Here is the PLoS Biology paper:
Cryptochromes Define a Novel Circadian Clock Mechanism in Monarch Butterflies That May Underlie Sun Compass Navigation:

During their spectacular fall migration, eastern North American monarch butterflies (Danaus plexippus) use a time-compensated sun compass to help them navigate to their overwintering sites in central Mexico. The circadian clock plays a critical role in monarch butterfly migration by providing the timing component to time-compensated sun compass orientation. Here we characterize a novel molecular clock mechanism in monarchs by focusing on the functions of two CRYPTOCHROME (CRY) proteins. In the monarch clock, CRY1, a Drosophila-like protein, functions as a blue-light photoreceptor for photic entrainment, whereas CRY2, a vertebrate-like protein, functions within the clockwork as the major transcriptional repressor of the self-sustaining feedback loop. An oscillating CRY2-positive neural pathway was also discovered in the monarch brain that may communicate circadian information directly from the circadian clock to the central complex, which is the likely site of the sun compass. The monarch clock may be the prototype of a clock mechanism shared by other invertebrates that express both CRY proteins, and its elucidation will help crack the code of sun compass orientation.

Here is the editorial synopsis:
In Monarchs, Cry2 Is King of the Clock:

Back in the brain, the authors showed that Cry2 was also found in a few dozen cells in brain regions previously linked to time-keeping in the butterfly, and this Cry2 underwent circadian oscillation in these cells, but not in many other cells that were not involved in time keeping. By taking samples periodically over many hours, they found that nuclear localization of Cry2 coincided with maximal transcriptional repression of the clockwork, in keeping with its central role of regulating the feedback cycle. This is a novel demonstration of nuclear translocation of a clock protein outside flies.
Finally, the authors investigated Cry2’s activity in the central complex, the brain structure that is believed to house the navigational compass of the monarch. Monarchs integrate information on the position of the sun and the direction of polarized light to find their way from all over North America to the Mexican highlands, where they spend the winter. Cry2, but not the other clock proteins, was detected in parts of the central complex where it undergoes strong circadian cycling. Some cells containing Cry2 linked up with the clock cells, while others projected toward the optic lobe and elsewhere in the brain.
Along with highlighting the central importance of Cry2 in the inner workings of the monarch’s clock, the results in this study suggest that part of the remarkable navigational ability of the butterfly relies on its ability to integrate temporal information from the clock with spatial information from its visual system. This allows the monarch to correct its course as light shifts across the sky over the course of the day. Other cues used for charting its path remain to be elucidated.

This is the PLoS ONE paper:
Chasing Migration Genes: A Brain Expressed Sequence Tag Resource for Summer and Migratory Monarch Butterflies (Danaus plexippus):

North American monarch butterflies (Danaus plexippus) undergo a spectacular fall migration. In contrast to summer butterflies, migrants are juvenile hormone (JH) deficient, which leads to reproductive diapause and increased longevity. Migrants also utilize time-compensated sun compass orientation to help them navigate to their overwintering grounds. Here, we describe a brain expressed sequence tag (EST) resource to identify genes involved in migratory behaviors. A brain EST library was constructed from summer and migrating butterflies. Of 9,484 unique sequences, 6068 had positive hits with the non-redundant protein database; the EST database likely represents ~52% of the gene-encoding potential of the monarch genome. The brain transcriptome was cataloged using Gene Ontology and compared to Drosophila. Monarch genes were well represented, including those implicated in behavior. Three genes involved in increased JH activity (allatotropin, juvenile hormone acid methyltransfersase, and takeout) were upregulated in summer butterflies, compared to migrants. The locomotion-relevant turtle gene was marginally upregulated in migrants, while the foraging and single-minded genes were not differentially regulated. Many of the genes important for the monarch circadian clock mechanism (involved in sun compass orientation) were in the EST resource, including the newly identified cryptochrome 2. The EST database also revealed a novel Na+/K+ ATPase allele predicted to be more resistant to the toxic effects of milkweed than that reported previously. Potential genetic markers were identified from 3,486 EST contigs and included 1599 double-hit single nucleotide polymorphisms (SNPs) and 98 microsatellite polymorphisms. These data provide a template of the brain transcriptome for the monarch butterfly. Our “snap-shot” analysis of the differential regulation of candidate genes between summer and migratory butterflies suggests that unbiased, comprehensive transcriptional profiling will inform the molecular basis of migration. The identified SNPs and microsatellite polymorphisms can be used as genetic markers to address questions of population and subspecies structure.

Here is an article written after the press release, which, as such articles usually do, greatly overstates the extent of the findings:
Clocking monarch migration:

In previous work, Reppert and his team showed that pigment-producing genes in the monarch eye communicate with the butterfly’s circadian clock. As part of the new study, Reppert and his team also found, in an area of the monarch brain called the central complex, a definitive molecular and cellular link between the circadian clock and the monarch’s ability to navigate using the sun. Briscoe said that Reppert’s study was “really going to overturn a lot of views we had about the specific components of circadian clocks.”

The spatial and temporal patterns of expression make Cry2 the most serious candidate for the connection between the clock and the Sun-compass orientation mechanism. Much work, both at the molecular and at higher levels of organization needs to be done to figure out the exact mechanism by which this animal, during migration, compensates for the Sun’s movement across the sky during the day, and thus does not stray off course. Cry2 appears to be a good molecular “handle” for such studies.
For background, see my older post on the initial discovery of Cry2 in Monarch butterflies by the same team.

Meet Fred Gould (sans mosquitoes) over pizza

Another thing I will also have to miss – the Inaugural Event of the 2007-2008 Pizza Lunch Season of the Science Communicators of North Carolina (SCONC), on October 24th at Sigma Xi Center (the same place where we’ll have the Science Blogging Conference). Organized by The American Scientist and the Burroughs Wellcome Fund, the first Pizza Lunch Session will feature Dr.Fred Gould, professor of Entomology and Genetics at NCSU (whose Insect Ecology class blows one’s mind – one of the best courses I have ever taken in my life). Fred recently received The George Bugliarello Prize for an interdisciplinary article Genetic Strategies for Controlling Mosquito-Borne Diseases. You can read an article about him in Raleigh News and Observer or, even better, listen to him on this podcast on State Of Things a few weeks ago. Notice with what disdain he utters the term “junk DNA” – only once in the entire hour – in order to explain it (away).

The Joys of Blogging Biology

One cool thing about being a blogging biologist is that one can write every day about sex with a straight face and then blame readers for “having a dirty mind”. But sex is so interesting – life would cease to exist without it and it is a central question in biology, so we have a license, nay, duty, to write about it all the time. We get all blase about it, I guess, compared to “normal people”. ;-)
One cool story that revolves around sex is making the rounds of the science blogosphere today. Jake Young explains in seemingly dry scientific language:

This issue has spawned a variety of weird behaviors and adaptations. For example, the males have spines on their intromittent organs (read: insect penises) that puncture the females insides. This is to discourage them from mating with other males. In response the females kick the males during mating to limit the damage done by the spines.
——————-snip—————-
The nuptial gift in part makes up for the reproductive cost of mating to the females, which is high in this case, but Edvardsson argues that this is probably not how it evolved. Instead, the large ejaculate probably evolved first so that the male would have more sperm to compete with other males. Then, the female evolved a way to utilize the water and nutrients in that already present sperm. “Well, hey…it’s here.”

Mo the Neurophilosopher adds the scary pictures while retaining the dry scientific tone:

A cost/benefit analysis is therefore essential to the mating behaviour of the female. The number of mating events must be strictly limited because of the resulting harm. But at the same time, the female’s needs for both sperm and water must be met.

The beauty of Pondering Pikaia is her ability to cut through all the complexity and say it like it is:

basically, females will trade sex for drinks
—–snip—–
possibly the most brutal looking sex organ I have ever seen.

So, go ahead and chuckle, you readers with dirty minds, but this is a really cool evolutionary story and if titillation brings in lay readers and gets them interested in the theory behind the scientific finding all the better. This is a good example of framing, isn’t it? Got your attention and got you interested in the underlying science, didn’t it?
Update: I see that Kate also joined the fray:

And no, he doesn’t believe that these findings generalize to other species. Including humans. So, if you’re planning to proposition a female beetle anytime soon, remember to bring along a bottle of water. You should be just fine.

Aphids and Enemies

You really don’t want to be an enemy of the aphids – two papers today! The first is quite straightforward:
Aphids Make ‘Chemical Weapons’ To Fight Off Killer Ladybirds:

Cabbage aphids have developed an internal chemical defence system which enables them to disable attacking predators by setting off a mustard oil ‘bomb’, says new research. The study shows for the first time how aphids use a chemical found in the plants they eat to emit a deadly burst of mustard oil when they’re attacked by a predator, for example a ladybird. This mustard oil kills, injures or repels the ladybird, which then saves the colony of aphids from attack, although the individual aphid involved usually dies in the process.

So, these aphids directly defend themselves against their own enemies by using the chemicals they derives from the plants they eat. But the next study introduces more complexity – several levels of the food web (i.e., tri-trophic relationship);
High Susceptibility of Bt Maize to Aphids Enhances the Performance of Parasitoids of Lepidopteran Pests:

Concerns about possible undesired environmental effects of transgenic crops have prompted numerous evaluations of such crops. So-called Bt crops receive particular attention because they carry bacteria-derived genes coding for insecticidal proteins that might negatively affect non-target arthropods. Here we show a remarkable positive effect of Bt maize on the performance of the corn leaf aphid Rhopalosiphum maidis, which in turn enhanced the performance of parasitic wasps that feed on aphid honeydew. Within five out of six pairs that were evaluated, transgenic maize lines were significantly more susceptible to aphids than their near-isogenic equivalents, with the remaining pair being equally susceptible. The aphids feed from the phloem sieve element content and analyses of this sap in selected maize lines revealed marginally, but significantly higher amino acid levels in Bt maize, which might partially explain the observed increased aphid performance. Larger colony densities of aphids on Bt plants resulted in an increased production of honeydew that can be used as food by beneficial insects. Indeed, Cotesia marginiventris, a parasitoid of lepidopteran pests, lived longer and parasitized more pest caterpillars in the presence of aphid-infested Bt maize than in the presence of aphid-infested isogenic maize. Hence, depending on aphid pest thresholds, the observed increased susceptibility of Bt maize to aphids may be either a welcome or an undesirable side effect.

Translation: transgenic corn has somewhat more nutritional value for the aphids. Thus, there are more aphids (per plant) on such corn. Thus, there is more “honeydew” (per acre) that they produce. Thus, there is more food (per acre) for the wasp. Thus, there are more wasps in the field. Thus, they are better able to control the population of moth caterpillars. Thus, there are fewer caterpillars to eat the corn. Final result: the farmer is happy. Now go to the paper itself and add comments, annotations and ratings to it.

That Gunk on Your Car

Jonah points to link by Kottke to series of close-up photos of insects splatered on windshields. The images are truly cool and not gross at all.
This immediately reminded me of a funny, yet excellent book I read a few years ago, That Gunk on Your Car: A Unique Guide to Insects of North America by Mark Hostetler, which helps you identify the insects by the shape, size and color of the splatter they leave on your windshield.

Just smelling food will make you live shorter – if you are a fruitfly

Just quickly for now without commentary:
Totally cool paper in the last Science:
S. Libert, J. Zwiener, X. Chu, W. VanVoorhies, G. Roman, and S.D.Pletcher
Regulation of Drosophila lifespan by olfaction and food-derived odors
:

Smell is an ancient sensory system present in organisms from bacteria to humans. In the nematode Caeonorhabditis elegans, gustatory and olfactory neurons regulate aging and longevity. Using the fruit fly, Drosophila melanogaster, we show that exposure to nutrient-derived odorants can modulate lifespan and partially reverse the longevity-extending effects of dietary restriction. Furthermore, mutation of odorant receptor Or83b results in severe olfactory defects, alters adult metabolism, enhances stress resistance, and extends lifespan. Our findings indicate that olfaction affects adult physiology and aging in Drosophila possibly through perceived availability of nutritional resources and that olfactory regulation of lifespan is evolutionarily conserved.

From Nature News:

Eating less can lengthen an animal’s life. But now it seems that — for flies at least — they don’t have to actually cut down on the calories to benefit. Fruitflies can boost their lifespan just by not smelling their food.
The result suggests that flies might use their sense of smell — as well as the actual consumption of food — to help determine how rich their environment is, and how they should go about distributing their energy resources.
From flies and worms to rats and mice, animals fed on restricted diets generally live longer than those given abundant food. No one is sure exactly why this is. One theory is that when times are tough and there is little food about, animals channel more of their resources into maintaining their everyday body function, at the expense of putting energy into reproducing. That can extend lifespan.
Scott Pletcher of the Baylor College of Medicine in Houston, Texas, wanted to find out what governs this decision. Smell, he thought, might be one determinant. “We wanted to see whether we could use odor to trick the flies into thinking the environment was more nutrient-rich than it actually was,” says Pletcher.
Normally, cutting a lab fly’s usual food intake in half lengthens its lifespan by about 20%, from 41 to 50 days. But exposing hungry flies to the scrumptious smell of yeast, a favourite food, took away some of this benefit, the team found. “About one-third of the beneficial effects on lifespan are lost,” says Pletcher.
The yeasty odor had no effect on the lifespan of fully fed flies.

And one of th authors gives additional explanation on the Nature News blog:

We measured the reproduction (fecundity) of OR83b flies and controls. Data is in fig 4a, there is no significant difference, when flies are fully fed. We did not present the data but the quality of eggs (percent that hatches, SL observation) seems to be unaffected. Even if flies would perform worser under stress (lay less eggs under stress for example) it is unlikely to be the cause of longevity, since during the longevity experiment, flies are not stressed in anyway.
It is possibe that the dfference is small, so that we can not detect it, but in this case it is unlikly to be the cause of 56% longevity extension.
Additionally, the work from Tatars lab for at least in some systems, uncoupled reproduction from longevity.

Invertebrate blogging of the month

Circus of the Spineless #16 is up on The force that through…

CO2 Receptors in Insects

Identification Of Carbon Dioxide Receptors In Insects May Help Fight Infectious Disease:

Mosquitoes don’t mind morning breath. They use the carbon dioxide people exhale as a way to identify a potential food source. But when they bite, they can pass on a number of dangerous infectious diseases, such as malaria, yellow fever, and West Nile encephalitis. Now, reporting in today’s advance online publication in Nature, Leslie Vosshall’s laboratory at Rockefeller University has identified the two molecular receptors in fruit flies that help these insects detect carbon dioxide. The findings could prove to be important against the fight against global infectious disease.

This is a very important finding. For context of the importance of CO2 in transmission of malaria, check out this.

Bioengineering a safer mosquito

Scientists building a better mosquito:

Without mosquitoes, epidemics of dengue fever and malaria could not plague this planet.
The skin-piercing insects infect one person after another while dining on a favorite meal: human blood.
Eliminating the pests appears impossible. But scientists are attempting to re-engineer them so they cannot carry disease. If they manage that, they must create enough mutants to mate with wild insects and one day to outnumber them.
Researchers chasing this dream, including an N.C. State University entomologist, know they may court controversy. Genetically modified crop plants such as soybeans, corn and cotton have become common in the United States, but an altered organism on wings would be a first.
Critics of bio-engineering, especially in Europe, view some genetic alterations as unnatural, even monstrous. People fearful of so-called Frankenfood could sound similar alarms over Frankenbugs.
But with advances in molecular biology and millions of dollars from the Bill & Melinda Gates Foundation, this quest may be within reach. And its promise is huge, the scientists say.

Fred Gould, the NCSU entomologist involved in this project, has started a blog and his lab has started a blog, but there have been no updates in months. Perhaps they will post something after this article came out. Or perhaps they can be prodded to post more by commenting or e-mailing them.
Update: This targeted approach is potentially much better than mass-killing and swamp-draining because the males (only females bite!) and many species of mosquitoes are beneficial ecological actors.

Honeybee genome completed!

The honeybee genome project has been finished and a bunch of papers are coming out tomorrow. As soon as they become available online I will comment, at least on the one paper that shows that the molecular machinery of the bee circadian clock is much more similar to the mammalian clock than the fruitfly clock – something that makes me very excited.
In the meantime, you can read more about the bees and their genome on The Loom, The Scientist, Scientific American and EurekAlert.

New study on evolution of vision

For easy-to-understand quick look at the evolution of vision I have to refer you to these two posts by PZ Myers, this post of mine, and these two posts by Carl Zimmer.
Now, armed with all that knowledge, you will curely appreciate the importance of this new study:
Compound Eyes, Evolutionary Ties:

Biologists at the University of California, San Diego have discovered that the presence of a key protein in the compound eyes of the fruit fly (which glow at center due to a fluorescent protein) allows the formation of distinct light gathering units in each of its 800 unit eyes, an evolutionary change to an “open system” that enabled insects to make significant improvements in visual acuity and angular sensitivity. In contrast, beetles (shown surrounding the fruit fly), bees and many mosquito species have the light-gathering units fused together into a “closed system.”
In a paper published in this week’s early online edition of the journal Nature, the scientists report that one of three proteins needed to form these light gathering units is present in the visual system of fruit flies, house flies and other insects with open eye systems, but conspicuously absent in beetles, bees and other species with closed systems. The researchers showed that the loss of this protein, called “spacemaker,” can convert the eyes of fruitflies–which normally have open eye systems–into a closed one. In contrast, the introduction of spacemaker into eyes with a closed system transformed them into an open one.
Charles Darwin was so enamored by the intricate complexity of the eye that he wondered how it could have evolved. “These results help illustrate the beauty and power of evolution and show how ‘little steps’–like the presence of a single structural protein–can so spectacularly account for major changes in form and function,” said Charles Zuker, a professor of biology and neurosciences at UCSD and a Howard Hughes Medical Institute investigator, who headed the research team.

Diversity of insect circadian clocks – the story of the Monarch butterfly

Blogging on Peer-Reviewed Research

Diversity of insect circadian clocks - the story of the Monarch butterflyFrom January 20, 2006, on the need to check the model-derived findings in non-model organisms.

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Revenge of the Zombifying Wasp

Revenge of the Zombifying WaspOne of the coolest parasites ever (from February 04, 2006):

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Cooperative Hithhiking

Baby bugs team up for sex scam

The moment they’re born, beetles of one species join forces for a curious drill.

The larvae hatch out of their eggs and together, as a group, climb to the tip of the plant. There, they secrete a sex pheromone that attracts a male of a bee who tries to couplate with the ball of larvae. They jump on him. He flies away carrying the little buggers.
When he finds a female to mate with, the larvae jump ship and go away hithhiking on her. When she goes back to her nest they disembark, eat the nectar she collected and her eggs before their final metamorphosis.
Arthropods are known to hitch rides on other animals, including larger arthropods, but this is the first documented case of a group hithchiking together.

Global Warming Remodelling Ecosystems in Alaska

Destructive insects on rise in Alaska:

Destructive insects in unprecedented numbers are finding Alaska forests to be a congenial home, said University of Alaska forestry professor Glenn Juday, and climate change could be the welcome mat.
Warmer winters kill fewer insects. Longer, warmer summers let insects complete a life cycle and reproduce in one year instead of two, the forest ecologist said.
Warm winters also can damage trees and make them less able to fend off insect attacks by changing the nature of snow. Instead of light, fluffy snow formed at extreme cold temperatures, warm winters produce wet, heavy snow more likely to break the tops of spruce trees, Juday said.

Ladybugs in un-lady-like places

How to collect and catalogue them.

Some hypotheses about a possible connection between malaria and jet-lag

Blogging on Peer-Reviewed Research

Some hypotheses about a possible connection between malaria and jet-lagHypotheses leading to more hypotheses (from March 19, 2006 – the Malaria Day):

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Another time-scale in insect brains

Bumble Bees Can Estimate Time Intervals:

In a finding that broadens our understanding of time perception in the animal kingdom, researchers have discovered that an insect pollinator, the bumble bee, can estimate the duration of time intervals. Although many insects show daily and annual rhythms of behavior, the more sophisticated ability to estimate the duration of shorter time intervals had previously been known only in humans and other vertebrates.
————-snip——————
Bees and other insects make a variety of decisions that appear to require the ability to estimate elapsed durations. Insect pollinators feed on floral nectar that depletes and renews with the passage of time, and insect communication and navigation may also require the ability to estimate the duration of time intervals.
In the new work, the researchers investigated bumble bees’ ability to time the interval between successive nectar rewards. Using a specially designed chamber in which bumble bees extended their proboscis to obtain sucrose rewards, the researchers observed that bees adjusted the timing of proboscis extensions so that most were made near the end of the programmed interval between rewards. When nectar was delivered after either of two different intervals, bees could often time both intervals simultaneously. This research shows that the biological foundations of time perception may be found in animals with relatively simple neural systems.

The Mighty Ant-Lion

The Mighty Ant-LionFirst written on March 04, 2005 for Science And Politics, then reposted on February 27, 2006 on Circadiana, a post about a childrens’ book and what I learned about it since.

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Neurons developing out ot Mesoderm?!

Snuck into the very end of this, otherwise very interesting article on neurobiology of cephalopods and moths, is this little passage:

As for flies, Tublitz outlined a tantalizing question, as yet unanswered, that has continued to take flight out of his lab for the last decade. Scientists for years, he said, have held “one hard rule” about what constitutes a neuron — that a neuron cell always arises from the ectoderm of a developing embryo. However, a discovery in Drosophila — fruit flies — has softened that assumption.
Cells arising from the mesoderm rest in a layer on top of the fruit fly’s nervous system, Tublitz explained. “These cells have all of the properties of nerve cells.” A slide shown during his talk displayed a long list of characteristics most often applied, with only few exceptions, to neurons. “Are these mesodermal cells nerve cells? I can’t answer that question conclusively, but we have generated data that suggest the answer may be ‘yes’.”

What Are Gonads For (Among Else)?

What Are Gonads For (Among Else)?
This post from January 21, 2005, is about insects, parasitoids and the mental approach to science:

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Friday Weird Sex Blogging – Losing Your Head For Love

As always, animal porn is under the fold:

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