Greenhouse whitefly, Trialeurodes vaporariorum is a major pest of horticultural and ornamental plants and is usually controlled with insecticides or biological control agents. In the current study, we examined the effects of synthesized zinc oxide nanoparticles (ZnO NPs) and Beauveria bassiana TS11 on T. vaporariorum adults. ZnO NPs were synthesized by precipitation method. Field emission scanning electron microscope images indicated that ZnO NPs were non-compacted uniformly. X-ray diffraction results confirmed the hexagonal wurtzite structure of ZnO NPs. Fourier transform infrared analysis showed an intense absorption peak at a range of 434-555 cm-1 related to Zn-O bond. In bioassays, adults were exposed to different concentrations of ZnO NPs (3, 5, 10, 15, 20 mg l-1) and fungi (104, 105, 106, 107, 108 spores ml-1). LC50 values for ZnO NPs and fungi were 7.35 mg l-1and 3.28×105 spores ml-1, respectively. Mortality rates obtained with ZnO NPs and fungi at the highest concentration were 91.6 % and 88.8 %, respectively. The results indicate a positive effect of ZnO NPs and B. bassiana TS11on adults. The current study was conducted under laboratory conditions, therefore, more studies are needed in field.

Heat shock proteins (hsps) protect proteins in eukaryotic cells from damage. Expression of hsps in insects subject to different environmental stimuli is poorly characterized. Here, levels of expression of the hsps genes (hsp40, hsp70, and hsp90) were recorded in Apis mellifera Linnaeus (Hymenoptera: Apidae) workers after exposure to sublethal concentrations of thymol, eucalyptol, α-pinene, trans-anethole, diallyl disulfide and infestation with Varroa mites. Our results show a dose-dependent up-regulation in the levels of all the hsps tested after the bees were treated with thymol, eucalyptol and α-pinene. Although these up-regulated expressions were statistically significant for hsp70 and hsp90 when the bees were treated with thymol and eucalyptol, they were not significant when treated with α-pinene. In addition, significant down-regulated expressions of the hsp genes were recorded in the diallyl disulfide treatment. The transcriptions of all the hsps tested were significantly down-regulated when pupae were infested with different numbers (0-5) of Varroa mites. Thus, it is likely that hsps can be used as biomarkers of survival when honey bees are under toxic and pathogenic stress, but this needs to be confirmed.

The effects of Carum copticum essential oil (CC EO) and thymol were assayed against fourth instar of Ephestia kuehniella Zeller by determining insecticidal activities and enzymatic responses. Concentrations of 5.42 and 6.81 μl/ml were obtained as LC₅₀ values for CC EO and thymol, respectively. The activities of esterases, aminotransferases, aldolase, and lactate dehydrogenase significantly decreased in the treated larvae by CC EO and thymol. Significant increases in glutathione S-transferases, γ-glutamyl transferase, and phosphatases were observed after treatment. Results revealed that CC EO and thymol significantly influenced the enzymatic activities of E. kuehniella leading to disruption of survival and metabolic responses.

Ephestia kuehniella Zeller is a key pest by severe deficiencies on quantity and quality of stored products. Due to concerns made by synthetic insecticides, use of natural products (like botanical insecticides) is of great importance as an alternative pest management. In the current study, the effect of diallyl disulfide was determined on digestive enzymes and those involved in intermediary metabolism of E. kuehniella. Concentration of 0.31% was obtained as LC₅₀ of diallyl disulfide followed by bioassay experiments. Activities of α-amylase, proteases, alanine aminotransferase, alkaline phosphatase and lactate dehydrogenase significantly decreased in the treated larvae, while the adverse effects were observed in case of triacylglyceride-lipase, aspartate aminotransferase, γ-glutamyl transferase, aldolase and acid phosphatase. Results confirmed that diallyl disulfide interrupted larval digestion by lower activities of digestive enzymes indicating significant effect on intermediary metabolism.