PRECOPULATORY BEHAVIOUR, MATING AND SEX RATIO OF BLACK FLIES SIMULIUM LINEATUM (DIPTERA: SIMULIIDAE) UNDER NATURAL CONDITIONS

Vilma Baužienė, Vincas Būda
2007 Acta Zoologica Lituanica  
Precopulatory and mating behaviour of stenogamous black fly species (Diptera: Simuliidae) Simulium lineatum (Meigen, 1984) was investigated under natural conditions. Polygynous males were found as single individuals or assembled in small aggregations (1.8 ± 1.1 individuals on average) on calami (above water height up to 50 cm) or in larger aggregations on cattails (above water height up to 100 cm). Females were found both among single males and aggregated. Males demonstrate precopulatory
more » ... ur (approaching, touching, attempting to copulate) both towards the female and male. The duration of touching and attempting to copulate differed significantly and lasted on average for: 13.5 ± 4.5 s when male interacted with a female and 6.9 ± 2.4 s when interacted with a male. The mean duration of copulation was 5.4 ± 1.1 min. The sex ratio of S. lineatum during the adults flying period was malebiased: during the first half of the season the ratio was 1:1.08 (by 4% emerged more males), whereas during the second half of the period the ratio was 1:1.4, with a significant shift of towards males (16%).
doi:10.1080/13921657.2007.10512811 fatcat:bkey2eszr5h7zooydttljzglia