Malaysian Stalk-eyed Fly

Teleopsis dalmanni belongs to Diopsidae within Diptera. Older experimental literature uses the combination Cyrtodiopsis dalmanni for the same species. [5][2]

The compound eyes and antennae sit at the ends of stalks extending sideways from the head. Male eyespan is strongly exaggerated relative to the female, producing a conspicuous difference in head proportions. [1]

Malaysian field records include 12 sites along or near the small Gombak road through mountainous rainforest. [3]

A laboratory experiment examined adult males aged 1–30 days. Thoracic, abdominal and total body mass increased with age, while flight capacity improved as the flight motor developed. [4]

Females prefer males with larger eyespan. In a controlled study, male eyespan predicted accessory-gland and testis length more effectively than body size alone, and females housed with large-eyespan males had higher fertility than those housed with small-eyespan males. [2]

The wild-population study linked smaller male eyespan with more female-biased broods associated with X-linked meiotic drive. This is a genetic system that distorts inheritance and consequently brood sex ratios. The association provides a possible route by which mate preference can reduce mating with drive-carrying males; it does not mean that every small male carries the same genotype. [3]

In the 2023 male flight experiment, males with longer eyespan were heavier and had larger wings and thoraces. Maximum flight capacity and wing kinematics were generally independent of eyespan. [4]