Résumé
The butterfly, citrus swallowtail Papilio demoleus L. is an important pest in nursery and young citrus trees in Iran and worldwide. It has received considerable attention among researchers. Here, we studied the physiological parameters ofP. demoleus L. (Lepidoptera: papilionidae) fed on four varieties of citrus (i. e. Citrus sinensis (L.) Osbeck, C. limon (L.) Burm.f., C. sinensis var. valencia, C. paradise Macfad.). The study was carried out under laboratory conditions (24±2°C, 65±10% RH and 16 h photoperiod). The 5th instar larvae showed highest relative consumption rate (RCR) by feeding on C. limon. The highest relative growth rate (RGR) (1.28±0.03) was recorded with C. sinensis. Efficiency of conversion of ingested food (ECI) (26.21±0.43) and Efficiency of conversion of digested food (ECD) (39.05±0.57) were highest with C. sinensis. The approximate digestibility (AD) recorded the lowest amount on C. sinensis. The highest activities of proteases were observed in the alimentary tracts of the larvae reared on C. sinensis var. valencia and C. paradisi at two different pH, pH 7 and 10. Chymotrypsin, trypsin, aminopeptidase, carboxypeptidase, α-glucosidase and β-glucosidase showed higher activities in larvae reared on C. paradise. While elastase and lipase showed higher activities in C. sinensis var. valencia, and α-amylase on C. sinensis. The amount of glycogen and triglyceride and total protein were higher in the hemolymph of larvae reared on C. paradisi, C. paradisi and C. sinensis var. valencia, respectively. The highest activities of gamma-glutamyntransferase, lactate dehydrogenase, alkalin aminoteransferase, alkaline phosphatase, acids phosphatase were observed on C. paradisi. However, the highest amount of aspartate aminotransferase was observed in C. sinensis var. valencia. Overall, these results indicate that the Citrus limon is an unsuitable host for Papilio demoleus.
Résumé
Aims: It is acknowledged that many essential oils isolated from various plants can exert toxic activity against insect species. In the present study, the essential oil from aerial parts of Agastache foeniculum (Pursh) Kuntze (Lamiaceae) evaluated for its larvicidal and physiological effects against the larvae of Tribolium castaneum Herbst. Place and Duration of Study: Place – Department of plant protection, Faculty of agriculture, Guilan university, Rasht, Iran. Duration – May, 2012 to January, 2013. Methodology: The essential oil was isolated from aerial parts of A. foeniculum by hydrodistillation method with a Clevengertype apparatus. In Larvicidal bioassay, five concentrations of the essential oil were prepared with acetone as solvent. Control samples were treated only with pure acetone. Ten same-aged instars were randomly selected, placed with treated diets and kept at 27 ± 2ºC and 60 ± 5% RH. The experiment was repeated four times and insect mortalities were recorded after 24 h. The effects of essential oil on total carbohydrate, lipid and protein contents on the surviving larvae were assessed. Also, the responses of general esterase and glutathione S-transferase as two detoxifying enzymes to essential oil were investigated. Results: A. foeniculum essential oil caused high mortality and the mortality was dose dependent i.e. with increasing of essential oil concentrations more mortality achieved. Furthermore, study on the effect of essential oil on total carbohydrate, lipid and protein contents demonstrated that all of them were decreased with increasing of concentrations. When A. foeniculum essential oil was applied, inhibition of esterase and glutathione Stransferase activities was observed. Conclusion: It has been found that the essential oil of A. foeniculum may produce a great range of biological effects on T. castaneum larvae and can be a potent candidate for such insect pest management.