Insecticidal activity of essential oils from two eucalyptus species on rhyzopertha dominica (coleoptera: Bostrichidae) and its effects on digestive enzymes of progenies | Actividad insecticida de aceites esenciales de dos especies de eucalyptus sobre rhyzopertha dominica y su efecto en r enzimas digestivas de progenies

The volatile fraction of essential oils from Eucalyptus globulus and Eucalyptus camaldulensis was used to evaluate their effective insecticidal toxicity against the lesser grain borer Rhyzopertha dominica (F.). Wheat grain samples were infested with the beetle and exposed to the vapors of different volumes (5, 10 and 15 μL) of the essential oils for different periods (24, 48 and 72 h). Emerging adults from each wheat sample were counted and analyzed in terms of amylolytic and proteolytic activity. Both essential oils were effective at promoting high amylolytic and proteolytic activity in emerged progenies, but only E. globulus caused lethal effects on the progenies (P < 0.05). By increasing the volume of E. camadulensis oil, the proteolytic activity of the insect increased, even at longest exposure time. The results of this study show that the volatile fraction of the essential oils from eucalyptus, especially E. globulus, is an effective insecticidal agent for controlling R. dominica in stored wheat