Biocontrol of the lesser date moth Batrachedra amydraula Meryrick(Cosmopteridae=Batrachedridae) on date palm trees.

摘要

Bioassays of some botanical extracts (matrine + emmamectine containing extracts from Sophora flavescens and Melia azedarach), granulosis virus, paraffined summer oil and bacteria toxin Bacillus thuringiensis subsp. kurstaki and plant extracts (matrine and matrine + emamectin benzoate) were conducted against the first generation of lesser date moth Batrachedra amydraula at several sites during two campaigns (2004 and 2005) in Saudi Arabia in order to assess their efficacy against this important pest in the region. Several trials focussing on biopesticides were conducted in date palm areas (Bicha, Riyadh, Haer and Oyayna) using the following bio-products according to the infestation level: Bacillus thuringiensis subsp. kurstaki (Condor) 300-1000 g/hl; Spinosad (tracer 480): 100 cc/hl; Carpovirisin: (CYD-X): 500 cc/hl; Sunspray 98.8% (summer oil) 1 l/hl; Matrine3: Herbal source: 150 cc/hl. A trial protocol was adapted to each region according to its specificity. The application was made at the rate of 3 to 7 litres per tree, washing all bunches of the tree according to the size of trees and their bunches. In each bioassay, samples of 400 to 500 fruits were analysed from each plot weekly during one month after treatment. The results showed that when applied at the time corresponding to the oviposition and hatching periods (a few days after fruit set), the biopesticides controlled the lesser date moth well. The protection period was important in plots treated with Matrine one, Sunspray7E and Bacillus thuringiensis Kurstaki, but was less important in the plots treated with Spinosad and Carpovirusin. The efficacy of all tested biopesticides was improved if good sanitation was applied in the orchard by removing over-wintering larvae in fruit stalks and dry fruits.