This is a short Blog about a few flies that I have photographed in Cheshire in the past week. All three look pretty scary, with apparent biting mouthparts of stings and fierce names. But all are harmless to humans and should be seen as fascinating rather than scary! I will try to argue the case that these are good guys and not the nasty beasts that at first glance they would seem.
The first of these is the Scorpion Fly, sounds like something to be avoided, doesn’t it? It also looks like it has got a fearsome sting that you would do well to steer clear of. In fact it is all bluff, these flies cannot sting us at all and are harmless. The ‘sting’ looks spectacular but is used for grabbing the female during mating, clasping her in his grasp until mating is over. So what looked like a nasty weapon to harm us turns out to be his way of keeping his female in his embrace whilst he makes sure that there will be lots more little Scorpion Flies soon! This species feeds on dead insects, even stealing from spiders’ webs, so it doesn’t even kill its prey, not a vicious beast at all!
Next up is the Dagger Fly, armed with a long needle-like projection from its head. It looks for all of the world like it would pierce your skin and suck your blood. This proboscis is only used to feed on other insects and it won’t bother humans, midges and mosquitoes are the ones to do that. One interesting little fact about this species is that the female won’t mate unless the male brings her a present of a dead insect for her to feed on. So he courts her with the fly equivalent of a box of chocolates, and just occasionally a bunch of flowers as sometimes he offers a bit of a plant if he can’t find an insect! He is really a true romantic, again proving himself to be nice rather than nasty.
Finally a fly that is big and buzzy and has a name which hints at eating the dead – the Flesh Fly, be afraid!!! Well if you’re a human, relax, it’s not out to get you. The Latin name of the family which they are classified in is Sarcophagidae, meaning flesh-eater in Greek and true their maggots do live on dead, decaying or sometimes small living animals, but not really humans. This though is one species that can have a detrimental effect on us, they carry parasites and diseases which can cause nasty illnesses in humans if digested. But usual hygiene precautions and thorough cooking takes this threat away. Again an interesting fact is that this fly can be useful to humans. Forensic entomologists use Flesh Fly larvae in particular to ascertain how long a person has been deceased, useful in murder investigations. So far from being the villain, this fly turns out to be the hero!
Appearances can be deceptive and in the case of these three species that is the case. All three have fearsome looks and scary names, but with a bit of background information they are more fascinating than fearsome.