Although this week’s insect, Melanophora roralis , is not originally from North Carolina, it has become well established in the Eastern US following it’s introduction from Europe many years ago. It is a member of the family Rhinophoridae, a difficult group to classify, having been considered part of the Tachinidae, Calliphoridae or Sarcophagidae in the past (see Wood 1981). Like tachinids, rhinophorids are all parasitoids of other arthropods, specifically wood lice (Crustacea: Isopoda) [though according to the wikipedia page, beetles, spiders and sometimes snails are also parasitized by this family].

Linnaeus first described the species as Musca roralis in 1758 (also describing specimens as Musca grossificationis, now a junior synonym). Meigen erected the genus Melanophora (with M. roralis as the type species) in 1803. The genus Melanophora was recently revised by Pierfilippo and Pape (2009).

Melanophora roralis is a typical-looking, cyclorrhaphan fly, similar in size and shape to house flies (Musca domestica). They are normally thin, shiny black, and with many large bristles; their wings are characteristically dark-brown/black. The species (and genus, since it is the only species in the US) can be easily recognized by a combination of the previous description plus the distinct wing venation, where the M vein is abruptly and anteriorly curved, ending in the R4+5 vein (see image below); other NC calyptrates do not have such a combination of characters. The sexes are also easy to separate since females have white wing tips (male wings are uniformly colored).

Melanophora roralis is a parasitoid of sow bugs in the family Oniscidae. Adults lay eggs on the ground in moist areas where these hosts occur. When the larvae hatch they actively search for their host, crawling in between the sternites of the wood louse when located. Larvae form a breathing sheath to the outside of the host and proceed to consume it from the inside. Melanophora roralis overwinters as a larva inside its host. Adult males can often be seen waiting on surfaces for females, and these flies are sometimes seen in windows of homes.

Melanophora roralis can be found in many habitats where their hosts are found, including deciduous forests and moist coastal areas, but are generally wide ranging.

Melanophora roralis is found in Europe (including the Mediterranean), North Africa, Israel, Cape Verde Islands and has been introduced to eastern North America and South America.

• Wood, D. M. 1981. 109. Rhinophoridae. in Manual of Nearctic Dipter Vol. 1. Agriculture Canada: 1187-1191.
• Pierfilippo, C., and T. Pape 2009. Phylogeny and re-definition of the genus Melanophora (Diptera: Rhinophoridae),
  with description of a new species from Sardinia. Zootaxa 2318: 552–565 [PDF]
• Jones, F. M. 1948. Notes on Melanophora Roralis (Linn.) (Diptera). Psyche. Volume 55:1 31-34.
• Melanophora roralis on Bugguide.net
• Currently there are no records available for this species in GBIF: http://data.gbif.org/search/melanophora%20roralis