mabolle

We haven't been testing directly for effects of human activities in our lab, but it's been observed that a lot of species are shifting or extending their seasons with the increase in temperature, especially spring temperatures. In some cases this includes adding an extra generation per year. It's even having evolutionary consequences: some species are changing their internal "calendars" to go into hibernation later in the year.

How close together where these different lifecycles? Is it sudden and side by side (one population in the forest and the other in the field next to it) ? Or is it a gradual change over many kilometres?

We're talking ~50 km for some of the populations I've been working with, but it can potentially be even more abrupt if you've got a sharp difference in the environment (mountain terrain to coastal is the strongest example). It also helps if the insects don't move much from one environment to the next, so that each population can accumulate its own genetic profile that locally adapts its life cycle. With voltinism (the number of generations per year, the focal trait of my thesis), the key environmental variable is the length of the growing season, which falls off pretty quickly as you move uphill (and more slowly if you move away from the equator). You only have time for several generations per year if the season is long enough to allow for it; otherwise you risk the whole population dying off if winter suddenly arrives when the insects aren't in their hibernation-ready life cycle stage. So they're under pretty strong selection to express a life cycle that works where they are.

To be clear, a pupa halfway through development contains two very different things: the famous "goop" — which is basically just materials left over from digesting larval tissues that the adult butterfly no longer needs — and the remaining living tissues, which will use the digested materials (along with fat reserves accumulated during larval development) to construct the adult body. The tissues which aren't broken down, but stay around for the whole metamorphosis process, include the brain, the respiratory system, several glands, and part of the gut. There are also the imaginal disks, which are bundles of stem cells that will grow into the adult insect's legs, facial features and reproductive organs.

So yeah, the "goop" itself isn't really alive; it's just a soup of raw materials. Move some of it into a different pupa, and it should be just as capable of using it as raw materials as its own "goop".

Maybe you think this is a bit of a cop-out, and you want to know what would happen if you took the living parts from inside a pupa and moved it into another pupa. The answer is that people have done this; transplantation is a classic (if disturbing) technique for investigating what parts of the body play what role during insect development. This even includes moving brains between pupae, and in some cases, transplanting organs between different species of insect. Insects don't have the kind of immune systems that vertebrates do, so they don't react as strongly to having foreign organs lying around inside them.

I haven't seen anything close to transplanting the entire left or right half (or top/bottom half) of a pupa's organs, though. It would be an incredibly fiddly and difficult operation to carry out, and I'm not sure what scientific question it would answer. But it seems possible that you could move quite a lot of stuff across and still produce an adult butterfly.

Insect numbers are, unfortunately, falling all over the world. This includes both the number of individual insects and the diversity of insect species in a given area. A lot of this is due to pesticide use, but I think the biggest problem (like with most biodiversity issues) is habitat loss; people are just a little too keen to "develop" land without leaving natural habitat around for other species.

People who own land can do more than most; there are ways of gardening and management that leave more space for insects, like growing a little meadow, providing overwintering sites, and planting food plants that insects like. I think we need to generally change attitudes around how we think about the spaces around us. Too much public land management is about creating really bland and empty spaces (like that suburban desert, the lawn) where almost nothing can live. People think of an uncut roadside as "untidy", but if you look closer, it's a tiny patch of meadowland with space for wildflowers and butterflies.

The biggest difference that any one person can make for the environment is probably through voting and activism. The stuff we're doing to nature is systemic, which means that protecting nature is ultimately a political issue.

I'd actually not heard of this, just googled it now. Here's an article about it.

People are suspecting that they were murdered for protecting monarch butterfly overwintering sites from logging. I can't comment on whether this is true, but what I can definitely say is that it wouldn't be the first time. It's not specifically connected to butterflies: activists, journalists and researchers working with various environmental issues are murdered quite frequently in South and Central America. In some of these countries, powerful economic interests combined with dysfunctional justice systems mean that trying to protect nature can be a dangerous business. :(

Hello to you and your awesome kid! Always so great to see enthusiasm for nature (especially insects, which obviously are the best).

I'm not big on childhood regrets, but I guess I wish I'd taken part in more nature-related activities. There's the Scouts, of course, but there are also more science-oriented youth organizations that provide courses and hikes and so on. It seems like a great way for a nature-interested kid to make like-minded friends.

I've been studying bugs in various contexts since about ten years ago, when I did my first insect diversity course at university. I did my bachelor's project on ticks and the bacteria that live inside them, and I've been researching butterflies for the past five years.

I do sometimes, but not often, pin bugs; I don't feel very bad about it. It's very hard to know for sure what it's like to be a different animal, but unlike larger animals like dogs or cats, it doesn't seem likely to me that insects are conscious or have feelings the way that humans do. All the same, I think it's good to respect any living thing and not kill them unnecessarily, so I understand anyone who doesn't want to pin bugs!

These days, I don't normally catch and kill bugs just to pin them, but I'll collect and pin bugs that I find dead, or that lived and died in the laboratory where we study them. I have two insect collections that I've mainly created as part as courses I've taken; one from Sweden and one from New Zealand. Eventually I'll donate them to science so that they can be kept at a museum or similar. Collections of preserved animals are very valuable to different kinds of research, because they let us see things like how populations have changed or moved around over time. (Digital collections are also valuable!)