Calliphora vicina

Calliphora vicina is a member of the family Calliphoridae, which includes blow flies and bottle flies. These flies are important in the field of forensic entomology. C. vicina is currently one of the most entomologically important fly species because of its consistent time of arrival and colonization of the body following death. C. vicina was described by the French entomologist Jean-Baptiste Robineau-Desvoidy in 1830. Its specific epithet is derived from the Latin vicinus 'neighbouring'. C. vicina is known as a blue bottle fly because of the metallic blue-gray coloration of its thorax and abdomen. It is distinguished from the commonly known C. vomitoria by its bright orange cheeks. The blue bottle fly is approximately 10–11 mm in length. The sclerites at the base of the coxa are yellow or orange. By chaetotaxy, the study of bristle arrangement, Calliphorids are characterized by having black bristles on the meron and two to three bristles on the notopleuron. The similarities between the different species of Calliphora can make identification of immature stages nearly impossible. From the first instar to the pupa stage C. vicina is identical to that of C. vomitoria. C. vicina goes through five generations in a year at a threshold temperature of 27˚ C (81˚ F). A female C. vicina can lay up to 300 eggs, on fresh carrion or on open wounds. The larvae go through three instar stages. The first instar hatches in approximately 24 hours after the eggs are laid. It goes through its second instar in 20 hours and its third instar in 48 hours. Under favorable conditions, the larvae feed for about three to four days. When the larvae complete their development, they disperse to find an adequate place to pupate. The C. vicina pupa stage last about 11 days. At 27˚ C, C. vicina’s life cycle lasts approximately 18 days. Climatic factors, such as temperature, are known to influence egg-laying and development of instar-larvae. In warmer weather the life cycle can last a little less, and in cooler temperatures the life cycle takes a little longer. Knowing the duration between the three instars and pupa stage and post-feeding larval dispersal can be useful to determine the post mortem interval in a criminal case. C. vicina are found throughout the U.S. in urban areas and are most abundant in early spring and fall where the temperatures are around 55-75˚F (13-24˚C). The species predominates in Europe and the New World, but has found its way into other countries via harbors and airports. It was first recorded in South Africa in 1965 when a specimen was collected near Johannesburg, but specimen collections have been few and sporadic since then. It also occurs as an exotic in Australia and New Zealand. One of the key characteristics of using blow flies in developing a post mortem interval estimate is the succession of insects that colonize the body. Based on the insects present at the time, a reasonable time frame for death may be established. C. vicina has its own part in the succession of the corpse.