Efforts have been made in search of effective and efficient ovicidal agents, yet insecticidal management of egg population has not been recommended for Aedes control. The susceptibility of eggs to different insecticides are reported to be significantly lower than their larval stages9394. Suman et al (2013) have found that the freshly laid Ae. albopictus eggs showed 80.6%, 42.
9% and 35.8% mortality for 1 ppm of pyriproxyfen, azadirachtin and diflubenzuron, respectively which was lower for Ae. aegypti eggs (47.3%, 15.7% and 25.5% respectively) 93.
Suman and colleague (2013) also found low ovicidal efficacy for the mosquito management at recommended concentrations of insect growth regulators 93. Other studies by Vasuki (1990) and Su and Mulla (1998) also reported the similar efficacy Culex quinquefasciatus eggs95. There is an interesting finding reported by Suman et al. (2015) which showed that pyriproxyfen performs the dual functions, one induces the hatching of diapause eggs at low concentration and other kills egg at the higher dosage7. The bottleneck is the dosage required for an ovicidal activity for Aedes mosquitoes are much higher than WHO recommended concentrations of insecticide but such dosage are not advisable to use for the control of mosquito control.
In future ovicides may become an important tool in mosquito management because eggs help population resurgence as well to overcome the adverse conditions. There is an urgent need to expedite research on ovicides for the development of better formulations with higher penetration to eggshell and embryonic membranes to enhance the efficacy at recommended larvicidal concentrations of insecticides, as well as effective delivery methods that can treat the cryptic habitats where eggs are hidden15. The ovicidal activity can delay population buildup by depleting the reserve of the mosquito population.