EFFECT OF MELIA-AZEDARACH FRUIT EXTRACT ON JUVENILE-HORMONE TITER ANDPROTEIN-CONTENT IN THE HEMOLYMPH OF 2 SPECIES OF NOCTUID LEPIDOPTERANLARVAE [INSECTA, LEPIDOPTERA, NOCTUIDAE]

The effect of an enriched methanolic extract of Melia azedarach L. (Me liaceae) fruits on the size of the corpora allata (CA), the juvenile h ormone (JH) titer and the protein content in the hemolymph of two lepi dopteran pests in Egypt, Spodoptera littoralis (Boisd.) and Agrotis ip silon (Hufn.), was studied, Different concentrations of the extract we re incorporated into an artificial diet on which the larvae were allow ed to feed. In S. littoralis, a significant reduction in the CA volume of larvae treated at the 1000 ppm extract level vs that of control la rvae was observed. In A. ipsilon, a reduction was found in the right C A gland only. Larvae of both species that had fed on a diet with Melia extract had a higher mean JH-II titer in the hemolymph than did contr ol larvae. In both species, the content of hemolymph protein was decre ased significantly after feeding for 6 days on a diet treated with con centrations above 50 ppm extract, followed by 6 days on a normal diet. The results show that a M. azedarach fruit extract has an effect on t he neuroendocrine control in the insects. The effect on the hemolymph protein levels is discussed in connection with changes in the morpholo gy/physiology of the gut.