Apalus bimaculatus (Coleoptera, Meloidae) is probably the first sign of the approaching spring if you are a coleopterist in Hungary. They usually appear in February when the temperature hits 10°C, first males fly above the weak grass in the sunshine.
Few days later females come out but they fly less, rather walking on the ground and waiting for the males to be attracted by the feromons. Since they move less, it is more difficult to spot them inspite the flashy color. This coloring may warn off the predators – mainly birds. The chemical what the body contains is cantharidin which causes painful blisters on the skin and who knows what else in the tract if swallowed.
This species parasitise solitary bees, primarily mining bees (Colletes sp.). Before the bees start their adult life, these beetles end their life cycle, females lay the eggs then die. The hatching larvae clamber the bees when they visit flowers, and travel to the nest to start the parasite life.
Mating begin immediately after one male meets the female. It usually takes only few minutes whilst they sit motionless, performing cooperative subjects. Otherwise capturing them may be painful, especially in warm sunny weather.
The species is surprisingly spreaded in urban areas, it’s known from several point of Budapest. The spot I have photographed them, found in the suburb, next to a subway station: