Some of the biological effects of ethanol extract of the green algae Ulva comparssa and Cladophora crespata in the blow fly Chrysomya megacephala Fabricius, 1794 (Diptera:Calliphoridae)

摘要

This study was conducted to evaluate the effect of the ethanol extracts of green algae Cladophora crespata and Ulva comparssa in some biological aspects of the blow fly Chrysomya megacephla . The results showed that the biological effects of ethanol extract of Ulva comparssa were highest on Chrysomya megacephala in the larval and adult stages, while the Cladophora crespata were in the pupal stage with many significant differences. The 1 st larval instar was most affected in the mortality after the treatment with ethanol extracts of two algae compared to 2 nd and 3 rd instars. The rates of mortality increases with the rise of extract concentrations; the most larval mortality of all experiments was in the concentration 2%, compared to 0.5% and 1%. The prolongation in the larval duration of the treated larvae was observed after the treatment with ethanol extracts compared to control. A reduction of pupation of C. megacephala percent was induced, a highly decrease in the pupation percent was observed in the treatments. Larvae raised on tested extract diets recorded a highly lower pupal average weight, a highly prolongation in the pupal duration was observed in all tested concentration of ethanol extracts. Results revealed a reduction in the percent of total pupae developed to adults. The application of ethanol extracts induced different morphological abnormalities, including larval-pupal intermediates, compressed pupae, darkened pupae, spherical shaped pupa, and small sized pupae. Many adults could not emerge completely and remained concealed in the puparia. The adults that resulted from some abnormal pupa were with defective wings, and deformed head or abdomen. The algal ethanol extracts caused high mortality of adults and longevity or duration.