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Entomology meeting, Things Learned

1. There are two major methods by which developing animals specify which cells will grow up to be reproductive tissue. One method, used by fast-growing animals, involves the establishment of a signaling gradient prior to cell differentiation. The other method involves local communication among cells after some cell division has occurred. The current state of the field involves connecting gene transcription patterns to developmental processes using transcriptomic methods (basically, measuring the amounts of all of the oodles of RNA present in different cells at different developmental time points). These methods are expensive, both in terms of sequencing costs (fancy machines that go Bing!), and the labor involved in data analysis.

2. Beekeepers frequently supplement beehives with extra protein sources. This might be okay if the protein supplementation only occurred occasionally, but in many cases people have gone beyond supplementation to constant supply. The problem with this is that many of the bee nutritional supplements have imbalanced amino acid profiles compared to the AA profile of pollen mixtures. This poses problems for honey bee colony performance (in terms of immunocompetence).

3. Some adult solitary bees are income-breeders who must feed on pollen as adults in order to mature and lay eggs.

4. As shown through a fairly simple lab assay, crazy ants can outcompete fire ants for food at intermediate and warm temperatures, but fire ants do better at a cooler temperature, probably in association with their comparatively larger body size.

5. Nosema is a microbial gut parasite in honey bees. Honey bees given pollen that has been diluted out with indigestible cellulose, and inoculated with Nosema, have fewer Nosema in their guts, but also have lower survival and a less favorable nutritional state than honey bees given full-concentration pollen. So, is Nosema really a gut parasite, after all?

6. If you rear Schistocerca americana grasshoppers in isolation (solitarious behavior), and then expose them to a high density of conspecifics for as little time as one hour, they'll switch to behaving like S. americana grasshoppers reared under crowded conditions (gregarious behavior).

7. Either I am getting sick, or there's something in the frozen Portland air that's invoking a sinus headache and allergies. Seems like an unusual time of year for allergies.



( 10 remarks — Remark )
Nov. 18th, 2014 01:35 am (UTC)
I don't understand number 4. Why do fire ants only live in warm areas if they outcompete the crazy ants in cooler areas?
Nov. 18th, 2014 02:24 am (UTC)
I probably oversimplified that whole story by assuming some prior knowledge of fire ant and crazy ant biology. Thing one to learn is that fire ants were introduced decades ago, I think over 50 years ago at this point. Crazy ants have only started to get a toehold in the US more recently. So what has been happening is that people have been noticing crazy ants taking over territories previously occupied by fire ants. One of the things they want to know is whether it will be possible to predict the extent of the replacement of fire ants with crazy ants. Fire ants are, indeed, temperature and water-limited at the extremes of their range, but what could end up happening is that crazy ants replace fire ants in warmer regions of the US, but fire ants retain residual populations in areas where it's too cool for crazy ants but still warm enough for fire ants.

All of this also kind of ignores the fact that both species thrive most strongly in habitats that have been human-modified. We humans are our own worst enemy in so many ways.
Nov. 18th, 2014 03:01 am (UTC)
Nah, they're adapting to us, or rather the new niches we've created: cities and farms. I can't see it as any different than the way lots of species have adapted to other niches created by successful organisms, such as reefs, forests, and grasslands. :) (Admittedly, those "successful organisms" represent entire orders, whereas little ol' us are still one species.)
Nov. 18th, 2014 05:32 am (UTC)
Mmm, that oversimplifies the history of the response to the RIFA "invasion," which also involved a "Kill It With Fire!" period that killed out a lot of other insect species. But it's hard to get a rational story on the fire ant situation because the human response isn't completely rational and there continues to be disagreement among scientists that employ vastly different methods in studying them.

Also, it's not simply a matter of adaptation - humans had a direct hand in transplanting both species to the North American continent - and so many other species to so many other continents, at that. The scale of the relocations is different. I'm not super hung up on the concept of "nativeness," but I do think it's worth pointing out that humans are conducting a whole bunch of studies on gene flow and selection on unprecedented scales.
Nov. 18th, 2014 08:11 pm (UTC)
"Oversimplified" is your word of the day? :)

But you are right: I forgot the strangest niche we've yet made, ships. The little wooden (and now metal) niche that moves other stuff with it.

I do think it's worth pointing out that humans are conducting a whole bunch of studies on gene flow and selection on unprecedented scales.
Well, unprecedented since the last continental joining. (South America and North/Central America? Or was there a recent land bridge between Asia and Australia? I can never remember.)
Nov. 18th, 2014 01:54 am (UTC)
I had no idea there were different strategies in cellular differentiation.

The solitary/gregarious behavior switch based on population has been suggested as a possibility for why we don't have locust swarms anymore, hasn't it?
Nov. 18th, 2014 02:27 am (UTC)
Re: cellular differentiation: I hadn't realized that, either!

Re: solitary/gregarious: not really...Schistocerca americana still has solitary and gregarious phases, but the gregarious phase doesn't swarm. I'm fuzzy on the details as to why not, but I believe it's partly associated with habitat modification by humans. Or it could have to do with differences in vegetation structure between areas with swarm-prone locusts and areas with swarmless locusts.
Nov. 18th, 2014 02:59 am (UTC)
Or some as-of-yet-unidentified nutrient that they don't get anymore.

I was reading today about the change in what oils people use for seasoning cast iron. Pig lard is significantly different than it was 100 years ago because their diet is so different, so now it's a poor choice compared to flaxseed, whereas it used to be the standard.
Nov. 18th, 2014 05:34 am (UTC)
It *might* be tied to nutrition, but colleagues of mine are still working out the details for certain locust species.

I'd heard of using lard to season cast iron, but it's still kind of unclear to me how the hydrocarbon composition of pig lard could have changed to that extent.
Nov. 18th, 2014 06:26 am (UTC)
http://sherylcanter.com/wordpress/2010/01/a-science-based-technique-for-seasoning-cast-iron/ is the article.
I don't know a lot about pig fat, so I'm unclear on her assertions, but her conclusion, that food-grade linseed oil is the best choice, sure make sense based on what I know of linseed oil and its traditional industrial uses. (Including bike wheel nipples, because its polymerization makes it act like a natural loctite.)
( 10 remarks — Remark )

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