The Crane fly, more commonly known as the Daddy long-legs, reaches peak numbers during the month of September and will no doubt prove this by crashing around your house, especially if you leave a combination of lights on and windows open!
Many people absolutely hate the random way they fly around, bashing into objects and suddenly dropping down onto unsuspecting observers; in fact, they were voted in the UK as the second scariest creature after the spider! What is more, there are plenty of them to be frightened of, as there are around 350 different species of Crane fly in this country and some 14,000 worldwide. They have also been around for a long time, as records show they first turned up in fossil records around 230 million years ago.
Apart from being called Daddy long-legs, Crane flies have many other country names including Mosquito hawk, Mosquito eater, Gallinipper and Jimmy Spinner. Interestingly they do not prey on mosquitoes and in fact rarely eat anything (occasionally some nectar) and certainly do not nip. Their only task in the two weeks that they live as adults is to mate, lay eggs and then die.
The male has a blunt end to the abdomen, but the female has a long-pointed end to her abdomen, resembling a large stinging needle, however it is actually her ovipositor for laying eggs in the ground and is not a weapon at all.
So why do they have such ridiculously long legs? Well, one theory is that they can land on top of grasses, each leg attached to the top of an individual blade of grass. If you have ever tried catching these creatures to expel them from your home, you will invariably land up breaking off one of their legs and feeling rather guilty that you were too rough. This may however be an evolutionary tactic which allows a leg to be simply discarded should anything grab it, allowing the individual to fly away “relatively” unharmed.
Apart from their long, gangly legs, I bet you did not know that craneflies have “drumsticks”!! If you look closely, you will see that these stick out from underneath each of their two wings, one on either side of the body. They are in fact modified hind wings, which are reduced to drumstick-like structures called halteres. These act as gyroscopes to maintain balance in flight.
The larval stages of the Crane fly are called Leatherjackets, because they have a tough rather leathery exterior. They can sometimes cause problems as they feed on the roots of grass and other vegetation. One infamous occasion was back in 1935, when bald patches appeared in the hallowed Lords cricket ground’s turf, causing angst amongst the ground staff. On the other hand, it rather pleased the spin bowlers who could use these patches to “turn” the ball!
Leatherjackets thrive when the weather is wet and warm, leading to explosion years when the adults seem to be everywhere. Many species of birds feed voraciously on both the larval stage and the adult fly. Sometimes Rooks and Starlings can be seen gathering in large numbers, feeding at close quarters in an otherwise ordinary looking grass field. The chances are that they have found a high density of leatherjackets – a favourite food. I have also watched literally hundreds of Swallows hawking low over grass fields in the autumn, and on closer observation have noted that they are catching good numbers of Crane fly.
Some scientists have begun to notice that with the hotter summers that climate change may be bringing us (not this year though!), the ground may be drying out more than it used to, and this may have a detrimental impact on the numbers of Crane fly that hatch out each year. As with all nature, everything appears to be so intricately linked, and the demise of something as common as the Daddy long-legs could have various knock-on effects that nobody has yet considered.
So, try to be patient with the next one that comes crashing into your house, as they may be a bit of a nuisance, but if nothing else they are an important part of the wider food chain.
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