Following the larval stage, further nutrition is required for the development of internal reproductive structures to reach sexual maturity.

[4] Adult flies exhibit solitary foraging behavior, feeding on rotting vegetative matter in the daytime.

[6] It has been suggested that the smaller size of the spermatophore is an adaptation to reduce investment in sperm due to a high mating frequency in a short amount of time.

[4] The eyestalks of T. dalmanni, as well as other Diopsidae flies, are frequently used to study the fields of sexual selection and mating preference.

This feature of the fly is subject to studies that investigate the genetic background of sexual selection, female mating preferences and reproductive consequences.

[5] Eyestalks play an important role in mating behavior, as studies have shown that females prefer males with larger eye spans relative to body length.

Teleopsis dalmanni eyestalks are an example of sexual dimorphism that has developed for mating purposes; larger eye-span is selected for as evidence indicates that it is preferred by females.

[11] This suggests that longer eyestalks developed in males as a result of mating success pressure, and hence are an example of sexual selection.

[11] However, studies cite a lack of evidence to support the idea that the extended eye-stalks are a handicap to male Diopsid flies.

While the eye-stalk increases the moment of inertia of male flies, they were not found to suffer a flight performance decrement.

[10] If longer eyespans do not pose a handicap to male flies, an alternative explanation may be more successful in explaining the development of this trait.