Ian & Julie asked:
What is a thunderbug? We only ever see them around harvest time, so where do they live the rest of the year? They seem to love light colours and skin to land on and they can be a pest as they are itchy especially when they stick to the suncream you wear. Lastly they crawl everywhere, into photo frames, behind computer screens and into smoke detectors which they then set off - why do they love these tight spaces and how and why do they trigger the alarms?
Kat Arney put this question to ecologist Felicity Bedford...
Felicity: - Yes. They’re something I come across quite a lot when I’m doing my field work because they’re found all across agricultural land. It’s something called a Thrip. You might have known about them as being called thunderflies, storm bugs, corn flies, corn lice, thunder blights, harvest flies. There’s so many names for these things because they do get everywhere.
Chris - I thought I had a dead pixel on my monitor on my computer..,
Felicity - Yes, don’t squish them…
Chris - ... because I had this black spot and then I realised that the dead pixel was moving and it had got behind the glass and in front of the LCD on my computer screen and there was a dead thing in there. And then it did die and I have got a dead pixel but it’s not a dead pixel - it’s actually a thunderbug that’s died in the screen in front of a pixel but it looks the same size and shape.
Kat - So what are they doing? They’re these little insects - are they helpful or are they just pests and why do they like getting into these tight spots?
Felicity - There’s about 6,000 species of Thrip and you wouldn’t really be able to tell the difference between them across the world because they are so small. But, looking at them under a microscope you would start to see slight differences between them and they’re basically feeding on plants across all of those different systems . So what you’re going to get is some of them are beneficial, some of them are helping with pollination but that’s quite unusual - they’re actually largely pests because they damage the developing bits of the plant. The ones which are attracted to your bright colours are flower thrips. So they go into the buds of flowers and that’s where they feed and reproduce.
Kat - So they’re attracted to different kinds of things so maybe Chris’ computer one - is that a computer thrip or…
Chris - Is it the colours that get them? Is it because my computer screen is a bright source of light and…
Felicity - Exactly.
Chris - ... that’s why they just make a B-line - if that’s the right word to use - a thrip line into the screen.
Felicity - So yes. Insects that need to feed on flowers are attracted to bright colours. It’s a fairly straightforward relationship between flowers and insects from that sense.