Sex ratio and adult behaviour of the Antarctic midge Belgica antarctica (Diptera, Chironomklae)

• Published in: Ecological Entomology
• Main Authors: EDWARDS, JOHN S., BAUST, JOHN
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1981
• Subjects: Antarctic; Austral; The Antarctic; Antarc*; Antarctic midge; Antarctica; Belgica antarctica
• Online Access: http://dx.doi.org/10.1111/j.1365-2311.1981.tb00611.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2311.1981.tb00611.x; http://onlinelibrary.wiley.com/wol1/doi/10.1111/j.1365-2311.1981.tb00611.x/fullpdf

Abstract. 1. The sex ratio in populations of the Antarctic chironomid Belgica antarctica approximates 1:1 at eclosion. 2. Male predominance in surface populations of the short‐lived adult persists throughout the summer. The mean ratio, based on data from surface aggregations (austral summer 1977–78) and from sticky traps (1978–79) is about 6:1, with a steady seasonal decline from 10–20:1 to 2–5:1. 3. Males live slightly longer than females but the difference does not account for observed ratios. 4. Samples of adult populations taken from subsurface sites have sex ratios nearer to equality than surface populations. 5. It is concluded that the male‐dominated surface populations are equivalent to the male swarms typical of winged Chironomidae. 6. Capture of airborne adults shows that aerial transport as well as water‐surface rafting may play a role in dispersal of adults.