How do you kill webworms?

Permethrin kills webworms. But it's important to know the kind of webworm. Specifically, different webworms require different treatment date. An example of treatment schedules follows:

1. Cotoneaster webworm [Athrips ranciDELLa] needs to be treated when the larvae first appear.

2. Fall webworm [Hyphantria cunea] needs to be treated in late June-early July, and then again in August-early September.

3. Juniper webworm [Daebomeris marginella] needs to be treated in late July-August. Spring treatments also may be needed in the case of heavy infestations and overwintering survivors.

4. Mimosa webworm [Homadaula anisocetra] needs to be treated every four or five days until populations are under control.

5. Pine webworm [Pococer robustella (Zeller)] needs to be treated in early June.