Cranefly image taken by Catherine O'Connell
While completing field work on Girley Bog, my colleague came across a cranefly (craein eitilt as Gaeilge). I was surprised to read that adult craneflies only live for two weeks, as this species spends most of its time as a larvae.
The adult has a slender body that measures approximately 25mm, and it is cream–brown in colour. The thorax supports the six legs and slender transparent wings.
You may know the cranefly as a daddy long legs. The legs of the cranefly are extremely long when compared to the body and it is thought these long legs help to prevent predation from birds. They certainly don’t help this species fly, and combined with their slender wings, the cranefly’s flight can be described as ‘wobbly’ at best.
The adult’s main purpose is to mate and for the female to lay eggs. You can actually tell the difference between a male and female adult cranefly due to the presence of an oviposter (a tube like structure at the base of the abdomen for laying eggs) on the female.
At first glance it looks very much like a part of the cranefly that is used for stinging — however craneflies don’t sting. The adults don’t feed or feed only on a small amount of nectar, as this short adult stage of their lifecycle does not depend on food.
The young of the cranefly are well known, they are called leather jackets and any gardener will tell you they are not a gardener’s friend! The adult cranefly lays eggs in moist soil in mid-summer. Some suggest up to 300 eggs can be laid and within two weeks the young hatch.
The leather jackets look like a caterpillar with no legs or defined head and they can be black, brown or even transparent in colour. It is what these leather jackets feed on that causes problems for gardeners. They are herbivores feeding on mostly dead plant material, but they also enjoy a feast of the roots of grass.
If you would like help identifying or to learn more about a wildlife species, contact me via e-mail email@example.com.