Brown Blowfly

Calliphora stygia has a brassy abdomen with a dense, tessellate golden dusting. The underside of the body and the femora and tibiae of the legs are yellow. Males are holoptic, meaning the eyes cover much of the head and almost meet dorsally, whereas females are dichoptic, meaning the eyes are separated from each other. This species resembles C. albifrontalis, another Australian species of Calliphora, but that species occurs in Western Australia whereas C. stygia occurs in the east. Other differences are that the upper third of the fore femora is orange in C. stygia but darkened in C. albifrontalis, and the minimum frons width of males is less than the anterior ocellus width in C. stygia but greater than it in C. albifrontalis.

Calliphora stygia has three life stages; 3 larval instars, pupa, and adult. In the larval stage, it is very difficult to determine the species; most entomologists wait until the adult emerges to identify specimens. Larvae feed on the soft tissues of a corpse or host that they were placed on by their parent. Due to their main source of food, C. stygia bioaccumulate toxins and heavy metals that may be present in the flesh. Insects can hold these toxins for months after the tissues disappear. These flies are also affected by weather conditions. The third instar is extremely tolerant to wet conditions, but perish at temperatures greater than 35 degree Celsius. Pupation, on average, take around 32 hours, but can take up to 48. This state can last as long as 3 weeks in wet, dark, and highly oxygenated conditions. Dry conditions tend to increase mortality rates. Emergence typically happens at dawn when environmental conditions are more humid, and more favorable to young flies. C. stygia don't appear to have a seasonal dependence for emergence; however they do have light and temperature cues. These flies are capable of emerging in the absence of those cues, and this is thought to be done with circadian rhythms that are set during the last instar before pupation. C. …