The Oriental fruit fly, Bactrocera dorsalis (Hendel) is an important quarantine pest around the globe. Although measures for its control are implemented worldwide through IPM and male annihilation, there is little effect on their population. Hence, there is a need for new strategies to control this minacious pest.
View Article and Find Full Text PDFOviposition site-selection in insects is mediated through innate recognition templates (IRTs) tuned to specific chemical cues. These cues aid gravid insects in choosing suitable oviposition sites and may even enhance the fitness of their offspring by warding off predators and parasitoids. However, studies on the evolution of oviposition site-selection and cues instigating oviposition in domesticated insects remain elusive.
View Article and Find Full Text PDFJ Invertebr Pathol
January 2015
Insects depend upon cuticular, humoral and cellular defenses to resist mycosis. However, entomopathogenic fungi through co-evolution have developed mechanisms to counter such defenses. Although a plethora of mechanisms of mycosis by entomopathogenic fungi are well-established, studies on the impairment of insects' antioxidative enzymes during mycosis remain elusive.
View Article and Find Full Text PDFCotton bollworm, Helicoverpa armigera, is one of the most damaging polyphagous pests worldwide, which has developed high levels of resistance to commonly applied insecticides. Mitochondrial P-glycoprotein (Pgp) was detected in the insecticide-resistant strain of H. armigera using C219 antibodies, and its possible role was demonstrated in the efflux of xenobiotic compounds using spectrofluorometer.
View Article and Find Full Text PDFBackground: Semiochemical is a generic term used for a chemical substance that influences the behaviour of an organism. It is a common term used in the field of chemical ecology to encompass pheromones, allomones, kairomones, attractants and repellents. Insects have mastered the art of using semiochemicals as communication signals and rely on them to find mates, host or habitat.
View Article and Find Full Text PDFSelecting a suitable oviposition site is crucial to the fitness of female insects because it determines the successful development of their offspring. During the oviposition process, an insect must use cues from the external environment to make an appropriate choice of where to lay eggs. Generalist insects can detect and react to a plethora of cues, but are under selection pressure to adopt the most reliable ones to override noise and increase efficiency in finding hosts.
View Article and Find Full Text PDFInnate recognition templates (IRTs) in insects are developed through many years of evolution. Here we investigated olfactory cues mediating oviposition behavior in the oriental fruit fly, Bactrocera dorsalis, and their role in triggering an IRT for oviposition site recognition. Behavioral assays with electrophysiologically active compounds from a preferred host, mango, revealed that one of the volatiles tested, γ-octalactone, had a powerful effect in eliciting oviposition by gravid B.
View Article and Find Full Text PDFPurified P-glycoprotein ATPase from Helicoverpa armigera (Ha-Pgp), reconstituted in proteoliposomes composed of phospholipids and cholesterol, shows higher ATPase activity in the presence of cholesterol than in its absence. The Ha-Pgp ATPase activity was increased 30-40% with cholesterol. The KM for ATP was found to be 1 and 0.
View Article and Find Full Text PDFThree major curcuminoids (I, II and III) were purified from turmeric and tested for their ability to modulate the function of P-glycoprotein ATPase of the insecticide-resistant pest Helicoverpa armigera (Ha-Pgp). The curcumin mixture inhibited the activity of Ha-Pgp ATPase by 80-90% at 100 μM concentration. Along with curcuminoids I, II and III, it inhibited the verapamil- and ethylparaoxon-stimulated Ha-Pgp ATPase activity.
View Article and Find Full Text PDFHelicoverpa armigera is a major pest of agricultural crops and has developed resistance to various insecticides. A P-glycoprotein (Pgp) with ATPase activity likely to be involved in insecticide resistance was purified and characterized from insecticide-resistant H. armigera.
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