The toxicities of 24 insecticides for the biological control of whiteflies were evaluated for Eretmocerus mundus (Mercet), Eretmocerus eremicus Rose and Zolnerowich and Encarsia formosa Gahan using the residual film method (for adults) and the dipping method (for pupae). Mortalities from insect growth regulators (IGRs) (flufenoxuron and lufenuron), Bacillus thuringiensis (Bt), pymetrozine and sulfur were\30% for both pupae and adults of all three species, indicating that the parasitoids were not seriously affected by these insecticides. Neonicotinoids (acetamiprid, clothianidin, dinotefuran, imidacloprid and nitenpyram), synthetic pyrethroids (etofenprox and permethrin), organophosphates (acephate and fenitrothion), chlorphenapyr, emamectin benzoate, spinosad and tolfenpyrad were seriously harmful (100% mortality) and acaricides (chinomethionat, milbemectin and pyridaben) were moderately harmful or seriously harmful to adult parasitoids (leading to mortalities of [92%). For each insecticide, the mortality of pupae was generally lower than that of adults, even though the toxicity classification for the two groups was similar. The results indicate that IGRs, Bt, pymetrozine and sulfur are relatively harmless, and are compatible with the use of parasitoids to help control whiteflies for integrated pest management in greenhouses.

No abstract

No abstract

The seasonal abundance of hymenopteran parasitoids reared from the agromyzid leafminer Chromatomyia horticola was monitored on garden pea in Shizuoka, central Japan, for 17 months between 2004 and 2005. The leafminer was abundant during the cool seasons (December to May) but parasitoid populations generally lagged behind the leafminer by approximately two months. Twenty-one parasitoid species were reared from C. horticola, and the most abundant parasitoid species were Diglyphus isaea, D. minoeus and Chrysocharis pentheus, comprising ca. 90% of the total number caught. Diglyphus isaea and D. minoeus were abundant during the cool season (December to May), while C. pentheus was abundant in the warm season (May to June). Other common parasitoid species were Dacnusa nipponica, Neochrysocharis formosa and Halticoptera circulus. The effects of two insecticides, malathion and tralomethrin, on parasitoid populations were investigated both in the cool and warm seasons. The insecticides caused a reduction in the density of most parasitoid species for at least one month and resulted in resurgence of the leafminer. However, the density of H. circulus increased after insecticide applications, suggesting that this parasitoid was tolerant to both insecticides but H. circulus could not reduce C. horticola populations when insecticide applications were made to the crop. These studies provide insight into the development of integrated control strategies of leafminer pests in field and glasshouse crops.

No abstract