Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae) established in the vicinity of Knoxville, Tennessee, USA.

The hairy maggot blow fly, Chrsomya rufifacies (Macquart) (Diptera: Calliphoridae) was collected in large numbers as both adults and immatures in the Knoxville, Tennessee, area during 1998 and is likely established there. The distribution of this species in the Old World, isothermal data, and its collection from mid-Michigan during 1998 suggest that it will eventually occupy most of the U.S. The forensic importance of C. rufifacies makes it probable that it will factor into an increasing number of medicolegal cases, but the expanding distribution of this species decreases its utility as a geographic indicator when postmortem movement of decedents is suspected.

The black soldier fly Hermetia illucens (Diptera: Stratiomyidae) as a potential measure of human postmortem interval: observations and case histories.

The black soldier fly, Hermetia illucens (L.), has been shown to be a ubiquitous inhabitant of both surface and buried human remains throughout the southern, central and western United States and Hawaii. Unlike most other species of forensically important Diptera, this species frequently dominates bodies in the dry/post decay stage of decomposition. Adults of the black soldier fly appear to initiate oviposition (egg laying) 20 to 30 days postmortem. Even at warm temperatures (27.8 degrees C), subsequent completion of the life cycle can require an additional 55 days. Life history data for H. illucens, when used in combination with data for other cohabiting arthropod species and viewed in the context of local environmental conditions, can provide medicolegal investigators with valuable parameters for estimating the postmortem intervals for badly decomposed remains.

Identification of a red "fiber": chironomid larvae.

During preliminary examination of the body of a homicide victim, a peculiar red "fiber" was noticed and recovered. Initially believing this to be a carpet fiber, the item was subjected to fiber analysis. It was found to be a short coiled particle not like any known natural or synthetic fabric fiber. Subsequent examinations determined this "fiber" to be the larva of a common freshwater midge (Diptera; Chironomidae). Chironomid larvae have been observed on other bodies recovered from freshwater environments. Entomological studies of this organism have led to the conclusion that the presence of chironomid larvae indicates submersion of the body.

Use of aquatic insects in determining submersion interval.

Although its potential is great, the use of aquatic insects in determining submersion intervals at death-scene investigations has not been exploited in the past. Aquatic environments have no known true specific indicator species, as do terrestrial habitats. However, aquatic environmental studies show that organisms may colonize a substrate dependent on factors such as size, position, exposure to current, water temperature, current speed, water depth, the presence of algal communities, or detritus. Certain aquatic insects such as the chironomid midges (Diptera, Chironomidae), and the caddisflies (Trichoptera), are capable of colonizing immersed bodies; and with the known biology of a specific species of insect for a certain geographic area, time intervals of submersion can be established.