Monthly Archives: February 2013

Getting lucky

Collecting flies while they are mating is a surefire way to establish conspecific identity. Many female phorids are extremely different in appearance than the males (search this site for lots of examples), and linking the two together can be almost impossible, based on morphology.
< Borgmeieriphora in copula

Borgmeieriphora in copula oblique

In this case, we have a pair of Borgmeieriphora collected in a Malaise trap by Wendy Porras in Costa Rica. The females are wingless, reduced creatures, which however have a sharpened, parasitoid type ovipositor. They lived in army ant colonies, but are rarely collected. The only large series of specimens known is a group that I caught over such ants at La Selva Biological Station many years ago. The males were flying over the ants, carrying the females, as many phorids do. Since then, males have shown up frequently in trap samples, but until now females almost never. This new capture was surely a huge stroke of luck, because most mating pairs separate before they die in the alcohol.

Something “new ” for Central America

When in Brazil a few years ago, my team of Giar-Ann Kung, Wendy Porras, and I found the spiny, brachypterous (short-winged) females of phorid genus Pheidolomyia. These flies, which live in the nests of the ant genus Pheidole, were only known from Brazil. Once back home in Costa Rica, however, Wendy quickly found them there, too. This demonstrates two important principles of dipterology: 1) Wendy is a great collector, and 2) our knowledge of the distribution of tropical flies is extremely fragmentary.

A female Pheidolomyia from Costa Rica - photo by Inna Strazhnik

A female Pheidolomyia from Costa Rica – photo by Inna Strazhnik

After I remarked on yet another interesting “South American” phorid fly showing up at La Selva Biological Station during the ALAS (Arthropods of La Selva) project, the ant ecologist Jack Longino agreed with me, only partly joking that “if you collect long enough at La Selva, you get the entire Neotropical fauna!” Now, that’s a hypothesis that would be fun to test.