I know, I know. I missed a few days/female scientists. It's been super-busy! I've been working 14+ hours a day, mostly nights, for the last week and my energy reserves are running kind of low.
To make up for it, I'll give ya a quick run-down on what I'm doing.
I study insect cold tolerance. But more importantly, I study what happens with multiple cold exposures. Can insects repair damage caused by chilling or freezing? Does a single cold exposure for a longer period of time cause more damage than many short cold exposures? Just how variable is climate now, and how variable will it be in the future?
There's a few systems I use to try and figure this out. One is using the woolly bear caterpillars I talked about before (they're freeze tolerant--more about that some other time) to repeatedly freeze and thaw them (and yes, they can survive that!). I can sort out then which damage is caused by being frozen and which is caused by being cold (two very different things!).
But what's been keeping me up at nights lately has been the fruit flies. I'm looking at the very common lab fly Drosophila melanogaster. We collected them wild from the London area last summer and fall, so we suspect they're likely more cold tolerant than the ones that have been kept in stock centres for decades (not individual flies, but the whole culture of them).
So I'm doing what I described before: I have some flies that I give a 10 hour exposure to -0.5 degC and some flies that get 5 two hour exposures (with one day in between) to the same temperature (plus a bunch of control flies of various treatments as well). And it's pretty nifty--more than 75% of them will survive that. Then, I take bunches of flies at 0, 24, 48, and 72 hours after their cold treatment and test them for lipid (fat), carbohydrate (sugar), and protein storage. I also give some of them boyfriends to see how many offspring they produce.
So what do I think I'll see? Well...there's a few different possibilites (assuming cold exposure causes damage visible in either fuel storage (those carbs, lipids, and proteins above) or in the number of offspring they produce):
1. Flies can repair damage caused by the cold exposure. So the flies given the multiple cold treatment will have higher fuel stores and more offspring compared to the sustained cold exposure.
2. Flies can't repair damage caused the cold exposure. So flies in both groups will have similar fuel stores and numbers of offspring.
Hmm... which is it? I won't know the answer until Christmas probably... but in the meantime, think about how important this is. If we know how flexible insects are at repairing damage from low temperatures, we can figure out better how where they can live if climate changes. And considering the number of insect-borne illnesses out there (Malaria alone kills 1 -3 MILLION people a year), understanding the ecophysiology of insects and temperature is so important!