In laboratory bioassays we tested the predatory capacity of the copepod Mesocyclops annulatus on Aedes aegypti and Culex pipiens larvae.A single adult female of M.annulatus caused 51.
6% and 52.3% mortality of 50 first instar larvae of Ae.aegypti and Cx.
pipiens respectively, in a 72 h test period.When alternative food was added to the containers, mortality rates declined to 16% and 10.3% for Ae.
aegypti and Cx.pipiens respectively.When 50 first instar larvae of each of the two mosquito species tested were placed together with a single adult female of depileve easy clean M.
annulatus, mortality rates were 75.5% for Ae.aegypti larvae and 23.
5% for Cx.pipiens larvae in a three day test period.Different density of adult females of M.
annulatus ranged from 5 to 25 females produced mortality rates of Ae.aegypti first instar larvae from 50% to 100% respectively.When a single adult female of M.
annulatus was exposed to an increasing number of first-instar Ae.aegypti larvae ranging from 10 to 100, 100% mortality was recorded from 1 to 25 larvae, then mortality declined to 30% with 100 larvae.The average larvae killed navy drapery fabric per 24 h period by a single copepod were 29.