Apis dorsata drone flights, collection of semen from everted endophalli and instrumental insemination of queens

We observed drone flights of 16 colonies of Apis dorsata in Chitwan, Nepal. At the end of February drone flights occurred between 18: 15 and 18: 35 h. By April, as day length increased, drones flew gradually later. Within 2 m onths the start of drone flights was delayed by 42 min. High correlation (r = 0.99) was found between the sunset time and the start of drone flights. After the thorax or abdomen of drones were squeezed, seven stages of endoph allus eversion occurred. Semen appeared as a small drop at the ventral side of completely everted cervix. We collected 8 mm(3) of semen from 41 drones . Thus, one drone produced on average 0.2 mm(3) of semen. Three Apis mellif era queens were inseminated with 2-3 mm(3) of A. dorsata semen. All queens started to lay eggs. Larvae hatched from 3% of eggs. After sealing of the l arvae, only drone pupae were found. We speculate that embryos in rest of th e eggs did not develop due to genetic incompatibility.