Entomologist George McGavin on bees, bites and gay insect rape

Were you one of those schoolboys who kept spiders in his pocket to scare girls?
Not really. I only got interested in insects and spiders on a university field trip. I was training as a zoologist and everybody was trying to find owls and badgers, which was hard. But at your feet were billions of ants doing very interesting things. I was in charge of the insect collections at the Museum of Natural History in Oxford for 25 years, doing research and teaching. Then in 2007 I resigned to concentrate on TV work – in half an hour on the box you can reach four million people.

Hit us with some amazing insect stats…
The majority of animals eat insects, so without them you wouldn’t have big animals or birds. There are 40 metric tonnes of insects for every human being – that’s the weight of four or five African elephants. And without bees we would lose a quarter of all our food because they pollinate the vegetables, fruit and flowers.

What’s the worst bite or sting you’ve had?
In South America, I threw a log off the path and hit a wasps’ nest. I got hammered with 150 stings and was close to anaphylactic shock. Then I had a scorpion sting in Guyana, which felt like a heated-up pin being stuck in my finger, though it was over in half an hour.

But they always kill people in films…
The scorpions in films are big black African scorpions and they hardly ever attack you. As a general rule, if it’s got fat claws and a thin tail, irrespective of its size, it’s probably okay because it will use its strength to overcome prey. If it’s got spindly claws and a fat tail, it relies on the sting. And that’s gonna hurt.

Have you discovered any brand new bugs?
Yes, three: a plant-hopper from Africa, a shield bug from Borneo and a handsome cockroach. Their names have ‘mcgavini’ at the end.

Ever had ants in your pants?
Yeah. In east Africa, I found this plant with a beautiful bug on it. As I was collecting it, I was aware of things crawling up the inside of my trousers. It was a column of driver ants. They only bit me when they got to my scrotum – I had 20-30 hanging on, and they have jaws. I had to take my trousers off and pick them off.

Not some of nature’s charmers then…
Actually, they can be useful. If you have a bad cut hold its jaws over the wound and it will chomp the skin and draws it into a neat little stitch. You then break off the rest of the ant.

Yuk. What insect skill would you most like to have?
Flying would be fantastic. It won’t ever happen, of course, because we’re too big. A pea, if it had wings, could fly easily though. It’s all to do with surface area and volume.

But were there once massive insects like in sci-fi films?
Yes, 300 million years ago when insects held sway over the Earth, some had a wingspan of 3ft. There was more oxygen in the atmosphere then, plus nothing had evolved to eat them.

We hear you’re partial to eating bugs…
It started 20 years ago in Papua New Guinea with fried beetles. They were nice, though bits of leg got stuck in your teeth. About 1,500 species of insect and spider are eaten. They’re a good source of protein, fibre, minerals, iron, calcium… I fry them up with a bit of garlic.

Any other tasty recipes?
I make nice appetisers: a small cracker with some avocado and a whole cricket sitting on top. And sometimes, I make bread using mealworms, which I roast until they’re dry then grind into flour.

Pound for pound, what’s the strongest insect on Earth?
Earwigs and ants can carry about 50 times their own weight, but they’re only strong because they are small. Fleas can jump 9in, but no huge animal could ever do the equivalent. You can’t scale it up.

What’s the best bug we can search for in Britain?
There are 21,000 insect species in the UK, and they’re all cool. Here’s one: the cabbage white butterfly. They lay eggs on crops and when the grubs are about middle-size, a tiny wasp flies down and inserts its eggs into some of them. The eggs hatch inside the grub but they don’t want to kill the host too early, so they just eat the fat tissue and leave the organs alone. Then, in the final hour, the 20-30 grubs go on a spree, eat the whole thing and emerge. If you’ve seen Alien where John Hurt has that thing popping out of his chest – that’s a picnic compared with this.

Any other bug stories you’d like to share?
The human botfly, a big bee-like fly, is fantastic. Its eggs go inside you, eat the flesh and leave a big boil. How it has evolved is really sneaky. They’ve worked out, if humans have a large fly on them, they swat it. So the botfly catches a smaller fly, such as a mosquito, glues its eggs on to the small fly’s abdomen then lets it go. As it feeds on your skin, the botfly eggs go straight in.

Do you keep live exotic bugs at home?
No. That isn’t my bag. Owning ten tarantulas can’t compare to the thrill of going into a Guyanese forest at 3am, finding one in its hole and having it in your hand.

Is there a thriving illegal insect trade?
Oh yeah – the rarer an insect is, the more it’s worth. Some people pay thousands of pounds. I’d shoot them all.

So is fly spray banned from your house?
It’s horrible, but I don’t want flies around the house so I use a rolled-up newspaper. I do think I’m crushing an incredibly evolved piece of miniature engineering, but I don’t feel guilty.

Got any insect mating rituals on film?
No, no! But insect sex is bizarre. Humans don’t have interesting sex. With insects, you’ve got homosexual rape, bondage, threesomes, gifts, murder – anything goes. In the US, for example, you’ve got two similar fireflies. If she’s feeling horny, the female of one species flashes a signal of her own species and attracts a mate. If she’s feeling hungry, she imitates a signal of the other species, attracting a male, which she then eats. So, if you’re having the come-on, you’re never sure if it’s gonna be a shag or a snack. Even in England, there’s the little empid fly. To attract a mate, the male has to offer the female a gift, so he catches a small insect and while she feeds on it he mates with her. A few of the flies have realised that if they wrap up the prey they get extra sex while she’s unwrapping it.

And the homosexual rapists?
One is the cave bat bug, which has a spike-like penis that can be stabbed into the body in a variety of places, including ‘up there’. Some of its sperm migrates to the testes of the ‘rapee’ and is passed on when that bug mates.

Is there one bug you’re still hunting down?
I’d like to see the giant Asiatic hornets in Japan. They attack and eat honey bees. But the bees have evolved a thermal technique where they grab the hornet, which is huge, and swarm all over it until it’s in a ball. By vibrating themselves, they fry it alive. Fantastic!