Oviposition of Aedes aegypti and Aedes albopictus on Ovitraps in Dry and Rainy Seasons in Southern Vietnam.

Ovitraps were set inside and outside of 15 households in December 2012 (dry season) and August 2013 (rainy season) in 2 communes (An Thanh and Phu Hoa) of Binh Duong Province in southern Vietnam. Eggs laid in the ovitraps were collected after 4 days, dried, and soaked in water. Hatched larvae were transferred to cups and reared to adulthood to identify the species. The rate of positive ovitraps did not differ between December and August for Aedes aegypti, but it was lower in December for Ae. albopictus. The number of eggs laid per ovitrap by Ae. aegypti did not differ between December and August, while that for Ae. albopictus decreased significantly in December in both communes. Moreover, Ae. albopictus laid eggs in ovitraps placed outside the households. Therefore, it is necessary for future studies to investigate whether the major source containers for oviposition had dried in the dry season or Ae. albopictus entered diapause, leading to these observations.