Scorpion Flies are one of the more unusual and less commonly seen insects. More often than not, they are mistaken for flies, in particular Crane Flies (order Diptera – family Tipulidae) because of their thin bodies and long legs. However, there are some physical and behavioural differences that stand out upon closer inspection.
As with most other flying insects, Scorpion Flies possess a pair of membranous wings (some have none) and a pair of compund eyes. Their antennae are long and filiform and they have long legs with clawed feet. But unlike flies, they have mandibulate (chewing) mouthparts at the end of their long proboscis.
The main diet of Scorpion Flies consists of fruit, pollen, nectar and mosses, although some males will also make a meal of small insects.
The male locates a female by tracking her pheromones. In some species, the male will offer an insect meal to the female, which is believed to help with egg development. After mating, the female lays her eggs in moist soil or leaf litter or in some cases water. The larvae, which have short legs and mandibles, moult three times while they are developing and will then pupate in the soil for a few months or so before emerging as adults.
Scorpion flies are usually found in moist areas in the more temperate parts of Australia, or in marshland in the inland regions. The order Mecoptera is represented by 27 species in Australia, Harpobittacus being the most common genus and the only one I have encountered so far.