Teleopsis

Teleopsis is a genus of stalk-eyed flies belonging to the family Diopsidae. The most notable characteristic of Teleopsis flies, and indeed the family Diopsidae as a whole, is the extreme lateral extension of their eyes, which are located on elongated stalks protruding from the sides of the head.

Teleopsis flies are found predominantly in tropical and subtropical regions of Southeast Asia, Africa, and Madagascar. They typically inhabit forested environments, often near streams and rivers.

The stalk length in Teleopsis males often plays a role in sexual selection. Males with longer eyestalks are generally more attractive to females and are more successful in competitive interactions with other males. This leads to a positive feedback loop, driving the evolution of increasingly long eyestalks in male populations.

The development of the eyestalks begins during the larval stage. The imaginal discs that will form the eyes and stalks differentiate early in larval development. The adult eyestalk length is influenced by both genetic and environmental factors, including nutrition during larval development. Poor nutrition can lead to shorter eyestalks in both males and females.

Different species within the Teleopsis genus can be distinguished based on subtle morphological differences, including the shape and size of the eyestalks, the coloration of the body and wings, and the arrangement of bristles on the head and thorax.

Research on Teleopsis continues to provide valuable insights into the mechanisms of sexual selection, genetic drift, and the evolution of exaggerated traits. They serve as a model organism for studying the interplay between genes, environment, and behavior in the context of evolutionary biology.