Delphinia picta is a sub-species of picture-winged fly in Ulidiidae. The specific name picta comes from Latin, and it means “painted.” It is the only sub-species in the monospecific family Delphinia. It is observed in the United States in the Midwest, on the East Coast from Florida to the borders of Maine across to western Kansas through eastern Minnesota. It can be found in El Salvador and Mexico. It is mistaken for a fruit fly species, but Delphinia picta does not feed on live fruits and living plant matter, as they are solely detritivores and eat decaying plant matter.
They also have been seen eating fermenting frass on black locust trees.
You can observe them anywhere there is decaying vegetation: landfills, swamps, temperate deciduous forests, and shaded fields.
Description
The best way to distinguish the species is by the separate pattern on its wings, which dark brown and shiny with a distinct hyaline background. Its body is about 5-7mm long with a light brown head, a black abdomen, brown thorax, and light brown legs. The ovipositor is around 1.20-1.35 mm long with two dorsal and one prominent ventral pairs of setae and several short setae on both sides. The ovipositor’s tip also has a bend downward.
Hosts
Larvae of this bug feed on severely decayed accumulations, sodden vegetation lazing on the surface of the ground or somewhat buried in the soil, on decaying fruit, and on other types of decomposing vegetation, including bulbs of wild garlic and commercial onions. In parts of Ohio, adult Delphinia picta was seen most commonly on herbaceous vegetation near refuse heaps and garbage dumps.
Life cycle
Delphinia picta Adults extensively raised in the lab usually live less than 30-40 days but can live up to 70 days. Mating occurs in the evening, just two days after an appearance from pupae. The young female will move her wings smoothly, and a male will react by flicking his wings before eventual copulation. Courtship may also incorporate one or more of the companions adorably blowing a bubble from their lips and mouth.
Pregnant females will lay up to 420-500 eggs in rotting herbaceous plant matter, which then hatches into larvae in 3 to 5 days. Larvae evolve through three distinct instar stages and enter pupae in 24–28 days, then finish pupating 10–15 days later. The growth is affected by the amount of daylight: Delphinia picta is a distinct multivoltine species with one generation going from April to June/July and the other eventually overwintering as mature larvae.
