Robber flies belong to that huge group of two winged flies, Diptera. Outfitted with sharp spines, bristles and spear-like mouth parts, robber flies voraciously hunt on other insects, attacking them in mid air, landing and devouring their prey’s innards, liquefied by toxic saliva. These are the jaguars of the fly world. Robber flies successfully attack and consume prey three times their own size. There are some 7000 species worldwide, and they are found in many diverse habitats. They range in size between the huge, 3 cm. Promachus , the largest fly in South Korea, to the tiny Stichopogon , just 4 mm. in length. Fossil robber flies have been discovered in shale, dating back 57 million years.

South Korea’s diverse habitats and temperate climate offer a rich environment for robber flies. An estimated 70 species, representing 10 subfamilies are here in scores of ecological niches all over the peninsula, some of them new to science.