[3] Derocephalus angusticollis flies found in the wild have accelerated speeds of development and age of mortality when compared to those in captivity.

Males have a larger build as well as exaggerated physical characteristics such as wider heads and longer limbs.

Like other flies within Neriidae, D. angusticollis has characteristic dorsocentral bristles located for the most part on their thorax as an identification marker.

[4] Derocephalus angusticollis flies demonstrated sexual dimorphism with males often presenting as larger and with more exaggerated traits than females.

[7][9] Researchers have demonstrated that early differences in nutrient content can impact D. angusticollis's ability to age successfully.

Males fed with high nutrient levels as larvae were able to develop more quickly, and reached their reproductive peak earlier on.

[10] Males with a nutrient-rich diet also experienced more rapid reproductive aging and ultimately died sooner than their poorly fed counterparts.

[10] High nutrient condition early in life is associated with rapid aging even in the absence of male-male conflicts that damage one's longevity.

Researchers have investigated D. angusticollis to search for evidence of telegony, which suggests that previous partners might be able to influence traits in offspring raised by subsequent males mating with the same female.

These effects were experimentally shown to come from a previous male that the female had mated with, not the genetic father of the offspring.

Compared to T. lineolatus flies, D. angusticollis have a larger rigid spike at the end of their distal section.

[5] As such, if the condition that the opponent is of similar size or smaller is met, the male challenges his rival by raising the anterior portion of its body and forelegs in a steep angle.

[15] Derocephalus angusticollis use chemical signaling by their levels of cuticular hydrocarbons (CHCs) during their social interactions.

Both genders have been observed to alter the levels of CHCs depending on where they fall in the social hierarchy of dominance.

[15] In a study that compared wild and captive D. angusticollis flies, researchers observed differences in both the speed of development as well as the age of mortality.