Enhancement of Bacillus thuringiensis with monosodium glutamate against larvae of obliquebanded leafroller (Lep.:Tortricidae)

Abstract

Monosodium glutamate, a taste enhancer widely used in food industry, was tested in the laboratory to determine its phagostimulatory effects on larvae of Choristoneura rosaceana (Harris). Larvae fed apple leaves treated with 50-700 lg/l monosodium glutamate increased leaf tissue consumption by approximately 40%. The stimulatory effect of monosodium glutamate (at 675 lg/l concentration) was maintained throughout 10 days of continuous exposure. Adding 675 lg/l monosodium glutamate to commercial formulation of Bacillus thuringiensis ssp. kurstaki, (DiPel Ò 2X DF), lowered LC 50 from 450 to 150 lg/l (P < 0.05, Lethal Ratio Significance Test), indicating good potential for monosodium glutamate to enhance B. thuringiensis-based formulations.

Recovery of Bacillus thuringiensis in vegetative form from the phylloplane of clover (Trifolium hybridum) during a growing season

“…Droplets (1 L) containing diluted crystal suspensions from vegetative isolates 2810-S-1 and 2810-S-6 were spotted onto cabbage discs (1 cm 2 ) and larvae were left to eat the entire disc before feeding them again with fresh cabbage, as required. The crystal suspension of each strain was diluted in sterile, distilled water containing 0.01% Tween 20 and 700 g L ¡1 monosodium glutamate as a feeding stimulant (Pszczolkowski et al, 2004). Three diVerent concentrations (50, 200 and 400 g mL ¡1 ) of -endotoxin suspension from each strain were tested.…”

The attractiveness of phagostimulant formulations of a nucleopolyhedrovirus-based insecticide depends on prior insect diet

“…Indeed, the eVectiveness of many feeding stimulants may be concentration dependent (Hostetter et al 1982), but the large volumes of spray applications (500-1,000 l/ha) for greenhouse crops means that only feeding stimulants that function at low concentrations are likely to be economically viable. Similarly, the culinary Xavour enhancer monosodium glutamate (MSG) and the more active product Sorbex (a mixture of MSG, inosinic acid and guanylic acid), that was tested at various concentrations (25, 50 and 100 parts per million, ppm), did not prove attractive to S. exigua larvae despite evidence that MSG has phagostimulant properties in tortricid larvae and can enhance the eVectiveness of bioinsecticides Pszczolkowski et al 2004).…”

Changes in the properties of Bacillus thuringiensis after prolonged culture in a rich medium

“…Droplets (1 μ l) containing diluted crystal suspensions were spotted onto cabbage disks (1 cm 2 ), and larvae were left to eat the entire disc before feeding them again with fresh cabbage, as required. The crystal suspension of each strain was diluted in sterile, distilled water containing 0·01% Tween‐20 and 700‐ μ g mol l −1 monosodium glutamate as a feeding stimulant (Pszczolkowski et al. 2004).…”