Kairomones of Heliothis armigera and Corcyra cephalonica and their influence on the parasitic potential of Trichogramma chilonis (Trichogrammatidae: Hymenoptera)

Kairomones from moth scales tend to influence the parasitic potential byTrichogramma chilonis Ishii. Hexatriacontane, pentacosane, heptadecane, docosane and 2, 6, l0-dodecatrienal-3, 7, 11-trimethyl were identified from the active moth scale extract ofHeliothis armigera Hubner (its natural host) andCorcyra cephalonica Stainton (a laboratory host). The significance of an array of compounds from moth scales with kairomonal activity for manipulating entomophagous insects in biological control programmes is discussed

Antibiotic effects of resorcinol, gallic acid and phloroglucinol on Heliothis armigera Hubner (Insecta: Noctuidae)

The antibiotic effects of 3 phenolic substances viz. resorcinol, gallic acid and phloroglucinol on the cotton bollworm Heliothis armigera Hubner were evaluated with particular reference to the feeding regimes, survival and pupation. Some of the characteristic antibiotic effects observed for resorcinol and phloroglucinol include reduction in consumption index and approximate digestability, increased efficiency of conversion of ingested food and efficiency of conversion of digested food, extended larval duration and high mortality. However, there was no alteration in the various food utilization efficiencies in the case of gallic acid treated individuals. The defensive response of the larvae to these toxic substances seems to be excessive defaecation. Frass analysis through thin-layer chromatography and ultraviolet characterisation indicated the presence of the ingested antibiotics, opening further avenues of investigation on the possible role of these antibiotics present in the frass in biological control

Influence of some plant phenolics on the activity of δ-endotoxin of Bacillus thuringiensis var. galleriae on Heliothis armigera

Bioassays with Bacillus thuringiensis var. galleriae Berliner δ-endotoxin and plant phenolics on Heliothis armigera Hubner enhanced the activity of B.t. var. galleriae endotoxin. The presence of plant phenolics with B.t var. galleria endotoxin not only reduced feeding potential and weight gain by the larvae, but also enhanced the LC50 value of the toxin. Our study demonstrates the effect of phytochemicals from resistant crop plants on the biocidal activity of B. thuringiensis strains in laboratory conditions