Eggs of aedes are hardy, say experts

Star: The aedes aegypti mosquito which used to breed indoors is now laying eggs outdoors, according to studies by Universiti Sains Malaysia.
Universiti Sains Malaysia (USM) entomologist Prof Abu Hassan Ahmad said the eggs had been found in tree crevices.
The aedes albopictus, another dengue carrier, also lays its eggs in tree crevices that are water-logged.
According to USM Vector Control Research Unit coordinator Assoc Prof Zairi Jaal, 90% of the aedes albopictus lay their eggs in trees.
“The eggs are hardy and can withstand dry conditions for up to six months,” he said, adding that the dried eggs would hatch faster than fresh eggs upon contact with water.
“Dried eggs hatch faster because they are highly stressed. Our lab tests have shown that when dried eggs are put in water and the air vacuumed out, they hatch within four minutes,” Prof Zairi said.
Both experts said the aedes aegypti, which is native to Africa, was the deadlier of the two species.
Aedes mosquitoes tend to feed in the evening when the sun goes down. The insect feeds on several people at one time, unlike the Anopheles (associated with malaria) that usually feeds on one victim.
“Mosquitoes are moving into suburban areas and no longer thrive only in urban zones,” said Prof Zairi.
“We have found the aedes aegypti even in Teluk Kumbar (in Penang), and that area is suburban.”
Uncontrolled development, he said, was one of the main causes for the change in the mosquito breeding pattern.
Prof Abu Hassan warned that dengue was here to stay. “There is no way to wipe out dengue locally or globally. The only way to combat the menace is to tackle public apathy.”
He said it was very important to reduce mosquito breeding sites, as fogging only killed the adult mosquito.
And draining water containers is not enough. The people must also clean out the containers.
“The mosquito eggs are stuck to the sides of the containers even when the water is drained. They can survive for six months without water and when they come into contact with water, they will hatch,” he said.