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.

The seasonal prevalence of the citrus red mite and its predators on Satsuma mandarin trees was surveyed by nakedeye observation and the beating method in three commercial groves in Shizuoka Prefecture in 2003 and 2004. Of the predators, only phytoseiid mites were caught mainly by beating, and their population dynamics were synchronized with those of the citrus red mite from June to September. Most adult females of phytoseiid mites caught by beating belonged to the species Neoseiulus californicus. Furthermore, one population of N. californicus caught from a surveyed grove showed development and oviposition on the eggs of the citrus red mite as well as the Tetranychus urticae eggs under experimental conditions. These results indicate that an indigenous population of N. californicus in conventionally controlled citrus groves in central Japan has the ability to suppress the population of P. citri on Satsuma mandarin.

Survey sites. Surveys were conducted in the ornamental production area located on the east coast of Lake Hamanako; chrysanthemum and gerbera, Gerbera spp., are primarily produced in this area in fields and greenhouses throughout the year. In this area, three chrysanthemum fields, two orchards, and three grasslands were selected for the survey.Plant sampling. Eighteen weed species were AbstractEighteen weed species were surveyed for western flower thrips (WFT), Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), from spring through autumn in 1994 within an ornamental production area in central Japan. WFT were collected from eight weed species and occurred as the predominant thrips species on most of the weed species in April. In early April, the densities of WFT adults and thrips larvae were high on racemes of common groundsel. From April to May, the densities of WFT on flowers of narrowleaf vetch, dandelion, and white clover increased rapidly. Between June and July, WFT adults inhabited predominately the Poaceae weed, but the density of their larvae was low. Furthermore, WFT became the minor colonizers on several weed species from August onward. These results suggest that WFT inhabit and reproduce predominately on numerous weed species flowering around the fields in spring, so the removal of weeds flowering in early spring is important for the control strategy of WFT.

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.

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