A study on the effect of some insecticides in controlling of fall webworm Hyphantria cunea (Lep.: Arctiidae)

Fall webworm moth (Hyphantria cunea Drury) was observed in Guilan province in 2002 for the first time. Now it has spread in a wide area and has been observed on many species of plants. The larvae of this pest after hatching lives and feeds in grouping form. Younger larvae soon produce a silken web and feed on the upper surface of the leaves.. As larvae grow webs are enlarged and cover more foliage. With respect to its wide range of host plants and the rate of damage, it was essential to survey and determine an appropriate chemical compound to control this pest. Therefore, in this research during 2004 to 2006, insecticidal effects of five safe pesticides including three kind of B.t. (Lepinox®-kurstaki and B.t. produced in Iran ), Dimilin® and Neem® on webworm moth were investigated in the form of a completely randomized design. Experiments were performed at the second larval instar of pest. Sampling was done three days after spraying. Final results showed that biological compounds based on Bacillus thuringiensis, specially Lepinox® and Kurstaki were successfull for controlling of the fall webworm and in many experiments they ranked in high level with high effect (65-97%). Dimilin® (45-98%), Iranian product of B.t. Talphigh Daneh® (37-80%) and Neem® (47-79%) with lower effect and higher fluctuation ranked in lower level.