Tagged: ecology

How to make a giant aluminum ants’ nest

The internets have been abuzz with this photo today:
ant nest

It’s a photo of an aluminum cast of an ant nest made by Walter Tschinkel, a Florida entomologist–but there haven’t been a lot of additional details.

The nest you are looking at is one of a Florida harvester ant, and appeared with many other photos and casts in a 2004 paper about nest architecture in the Journal of Insect Science.  They are things of great beauty, and tell us a lot about how ants build.

The uppermost portions of a medium-small Pogonomyrmex badius nest

The uppermost portions of a medium-small Pogonomyrmex badius nest

This series of photos, for example, shows how the complexity of the nest structure grows as the colony adds workers.  You can find more amazing photos of different types of ant nest casts here in a 2012 article.

There is even a video of the process of making these casts! And yes, don’t do this at home. Even if Dr. Tschinkel did publish detailed instructions on all the different ways to make an ant nest cast.  I am looking at you, Mr. Treelobster.

I would be remiss if I did not also link to this older video that uses ten tons of cement to discover the extent of a much larger African South American ant nest. (I am told it’s Atta vollenweideri, and it was dug up in South America. Thanks for the correction!)


Tschinkel W.R. (2004). The nest architecture of the Florida harvester ant, Pogonomyrmex badius., Journal of insect science (Online), PMID:

Tschinkel W.R. (2010). Methods for Casting Subterranean Ant Nests, Journal of Insect Science, 10 (88) 1-17. DOI:

Lousebusters!

A fabulous new development in louse control! I’ve written before about the problem of head lice becoming resistant to commonly used pesticides, making treatment much more difficult.  A new device received approval from the FDA to be this year–and it’s a lot of hot air.
No, really:

Goates, B., Atkin, J., Wilding, K., Birch, K., Cottam, M., Bush, S., & Clayton, D. (2006). An Effective Nonchemical Treatment for Head Lice: A Lot of Hot Air. PEDIATRICS, 118 (5), 1962-1970 DOI: 10.1542/peds.2005-1847

ResearchBlogging.org

This device is a great story of how basic ecological research can lead to improvements in human health.  It all starts with birds.

Those of us who keep chickens or work with wild birds know that they have an amazing assortment of ectoparasites–parasites that live on the outside of the body (“ecto” = external). Most of these are called “feather lice.”

Feather lice are a fascinating group of animals; the researchers in this lab have studied, among other things, how lice have evolved to match the color of their host birds.  I think it’s safe to say that Dr. Dale Clayton, the lead researcher in this story, is Mr. Bird Lice.   Over the last 2 decades, he’s published a steady stream of fascinating papers (and books!) about lice and their co-evolutionary relationships with their hosts.

It was because of Clayton’s research that the University of Utah lured him away from his job at Oxford in the late 1990s.  Unfortunately, Clayton discovered exchanging  jolly old (damp) England for Utah’s arid climate made keeping his lousy subjects alive extremely difficult.  In fact, his lice colonies dried out and died.
Having dead research subjects will put a serious dent in one’s research productivity.

His travails in lice-rearing, however, were what set a lightbulb off when his children came home with head lice. If his research lice dessicated and died, could he make head lice dry out and die too?  Alas, it proved to be a much harder puzzle than he thought:

“Over the next several years a variety of methods were tested in Clayton’s lab, ranging from the use of chemical desiccants, to heat caps fitted with electrodes, to rice bag caps heated in a microwave, to various hair dryers and blowers up to the size of a leaf blower

His lab website says that “student volunteers” were used as his guinea pigs. Once again, a novel use for graduate students is discovered!graph of results

After almost 20 years of tinkering, the Lousebuster is now FDA approved and on the market. It also happens does a really, really good job of killing the insects using only hot air!

I know what you are thinking–unfortunately, it is not enough to have a blow-dryer, as you can see here in the results comparing the percent of lice being killed with different methods.  (I also am rather relieved that wall-mounted hand driers were not effective.  I can only imagine the lines at the airport bathroom if families traveling decided to do a little de–lousing between connections.)

The other nice item is that the company selling the Lousebuster requires that anyone purchasing them be certified in their use.  That means that no one should have a scalded scalp, and it should actually perform at the 95-99% louse mortality levels reported in various publications.

A newer version released December 2010 is quieter and “works on curly hair”.

So hoist one to toast Dr. Clayton and his lab in their demonstration of how basic research  pays off for all of us!!

Teaching Resources Online for Ecology

Some of you have already found TIEE, but if not…You can find a huge wealth of info and teaching tips at the Teaching Issues and Experiments in Ecology website.

Many open-access articles and some great resources. This includes data sets, slides, and tips on things like running a “turn to your neighbor” exercise.  There is also an essay titled Helping Your Students Interpret Figures and Tables: “Step One-Step Two.”  Alas, the inability to read a graph is a major problem for college freshmen.

BTW, Another useful resource is the SERC site for geology faculty, which has a ton of info on peer review in the classroom.

Enjoy!

Biocontrol and unanticipated consequences

An interesting story (and podcast!) in the news today:

Biocontrol agents, such as insects, are often released outside of their native ranges to control invasive plants. …As early as 1971, U.S. scientists began releasing gallflies in an effort to reduce populations of invasive [spotted knapweed]. Like all biocontrol agents, the gallflies were selected because of their specificity to their host plant, leaving little risk of direct harm to other plants…

Scientists and managers expected that this seed deficiency would lead to limited knapweed population growth. An unanticipated side effect, however, involves the flies’ furry neighbors. At the foot of the Sapphire Mountains in western Montana, omnivorous deer mice, whose diet usually consists of native seeds and insects, have also begun to prey on the introduced gallflies.

The abundance of knapweed leads to lots of gallfly larvae, which serve as a food subsidy for the mice. Pearson and his coauthor, Ragan Callaway of the University of Montana, found that this extra nourishment bolsters mouse population size, increasing the numbers of hungry mice feeding on their original source of food: the seeds of native plants. As mouse consumption of native plant seeds increases, fewer native plants survive past the seed stage.”

Full reference to the paper:
Pearson DE, Callaway RM (2008) Weed-Biocontrol Insects Reduce Native-Plant Recruitement through Second-Order Apparent Competition. Ecological Applications: Vol. 18, No. 6 pp. 1489–1500.

A very nifty study, if a bit depressing. It’s really impossible to do just one thing when dealing with ecological systems. The complex community interactions among mice, native and invasive plants, insects, and seeds in this study is a nice demonstration of that principle.

More info on Spotted Knapweed:

Ecology Digital Library

A message from the Ecological Society of America–I know a lot of folks have lovely images on their blogs, and thought they might consider contributing.

Do you have digital images – including photos, figures, or tables – that have potential value for undergraduate ecology courses?   If so, you can publish those images through EcoEd, which is the Ecological Society of America’s online library of free digital resources for teaching undergraduate ecology.  All images will be peer reviewed for scientific accuracy and pedagogical value.

Extended deadline for image submissions: 5 September 2008.

Accepted images will be made available through the EcoEd website. Images will be searchable through EcoEd and a larger biology library, the Bioscience Education Network (BEN).

EcoEd DL is managed by the ESA’s Education and Diversity Programs Office and is advised by a committee of ESA members.   It is supported by a grant from the National Science Foundation.

For more information about the submission process, visit http://www.ecoed.net/pages/submit or contact [emails removed]….Opportunities also exist for individuals to serve as reviewers.