Wikipedia
Lonchopteridae
The Lonchopteridae (spear-winged flies or pointed-wing flies) are a family of small (2–5 mm), slender, yellow to brownish-black Diptera, occurring all over the world. Their common name refers to their pointed wings, which have a distinct venation. Many are parthenogenic; males are very rare, however, at least in North American species, and have a somewhat different venation than do the females. Spear-winged flies are common in moist, shady, grassy areas, where the larvae are found within decaying vegetation. One species, Lonchoptera bifurcata, is cosmopolitan in distribution, and may have been transported via shipments of vegetables.