Effect ofMelia azedarach fruit extract on juvenile hormone titer and protein content in the hemolymph of two species of noctuid lepidopteran larvae [insecta: Lepidoptera: Noctuidae]

The effect of an enriched methanolic extract ofMelia azedarach L. (Meliaceae) fruits on the size of the corpora allata (CA), the juvenile hormone (JH) titer and the protein content in the hemolymph of two lepidopteran pests in Egypt,Spodoptera littoralis (Boisd.) andAgrotis ipsilon (Hufn.), was studied. Different concentrations of the extract were incorporated into an artificial diet on which the larvae were allowed to feed. InS. littoralis, a significant reduction in the CA volume of larvae treated at the 1000 ppm extract levelvs that of control larvae was observed. In A.ipsilon, a reduction was found in the right CA gland only. Larvae of both species that had fed on a diet withMelia extract had a higher mean JH-II titer in the hemolymph than did control larvae. In both species, the content of hemolymph protein was decreased significantly after feeding for 6 days on a diet treated with concentrations above 50 ppm extract, followed by 6 days on a normal diet. The results show that aM. azedarach fruit extract has an effect on the neuroendocrine control in the insects. The effect on the hemolymph protein levels is discussed in connection with changes in the morphology/physiology of the gut.