March 2012. A question about Dipel: is it effective against bagworm. Presumably, as this was a question asked by staff at OPRA, PNG, it concerned oil palm.
The answer came indirectly from one member who said that success will depend on getting the chemical onto whatever the bagworm is eating. The larvae must ingest the residue for the toxin to be active in the alkaline gut of the larvae.
It was reported that Malaysia used Dipel to control large outbreaks of bagworm in Perak during October 2011. In addition, flowering trees such as Cassia cobanensis and the vine, Antigonon leptopus (Coral vine) were planted as food sources for natural enemies.
A member of staff of one of the oil palm companies (FELDA) in Malayia replied that Dipel was about 75% effective as an aerial spray, whereas cypermethrin was 98%. At least five rounds of spraying was required to get effective control as Dipel is effective only at the early instar stage. By contrast, only one application of cypermethrin is required.