Survival of citrus thrips, Scirtothrips citri (Moulton), propupae and pupae was investigated by seeding emergence traps with known numbers of larvae and recovering emerging adults. Results from traps in the field and undisturbed soil cores in the laboratory suggest that frequent irrigation and some autoclave-excludable factors suppress survival of citrus thrips. The autoclave-excludable factors exhibited a more pronounced suppression at 20 and 25ºC than at 18 or 30ºC, but the effect appeared to be relatively independent of gravimetric water content. Adding Berlese extracts, or water-leaches from suppressive soils to autoclaved soils did not result in reduced survival. Exposing citrus thrips larvae in screen cages to the soil microflora and fauna did not yield any evidence of virulent pathogens. Adding decollate snails, Rumina decollate (L.), to autoclaved soil cores resulted in significant suppression. Assuming that adult migration from adjacent groves contributes only marginally to the population increase in a particular orchard, citrus thrips levels may be reduced through frequent irrigation and inoculative releases of decollate snails. However, large-scale field studies remain to be carried out to judge the practical feasibility of such tactics.
Document Type: Research Article
Publication date: April 1, 1997
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Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.