KILDARE WILDLIFE COLUMN: Yellow Dung Fly lays eggs in animal pooh

There are over one million known species of fly. Flies are invertebrates, that is they don’t have a backbone and while there are many species that don’t have a backbone, to be classed as a fly they must have certain characteristics.

Flies have one pair of wings and these wings give them great movement in flight. Their movement in flight is supported by their hind legs that have two clubbed shaped organs known as ‘Halteres’ that provide information on the rotation of their bodies. They have large compound eyes and large mouthparts for piercing and sucking their prey.

This week one of the most common flies you can come across is known as the Yellow Dung Fly. This fly is so called as it lays its eggs in the dung of mammals including deer, cattle and sheep.

Their young provide an important service for us in breaking down animals dung in our fields returning valuable nutrients to the soil. Both the male and female are golden yellow in colour. You can identify between the male and female by looking at the front legs, the males are covered in orange to yellow coloured fur while this fur is absent in the females.

After mating the male will guard the female as it is known that the females can mate with multiple males before laying their eggs.

After 1-2 days the larvae hatch and burrow into the dung for protection. Their growth is dependent on temperature as the larvae will only begin to molt once the temperature reaches 20 degrees celsius. They will then move into the soil and pupate, however once again the length of time before they will emerge as an adult depends on the temperature.

At temperatures of 25 degree celsius it can take as few as 10 days, however during times when temperatures are lower than 10 degrees celsius, it can take up to 80 days to complete pupation.

The adults feed on smaller insects and live for two months. Don’t forget if you come across a wildlife species that you would like help identifying I would be happy to help, contact me at bogs@ipcc.ie.