LEUCOKININ II A NEUROPEPTIDE HORMONE AFFECTING BIOLOGICAL AND BIOCHEMICAL ACTIVITIES OF THE EGYPTIAN COTTON LEAFWORM Spodoptera littoralis (BOlSD.)

Salem,, M. S.; El-Maasarawy, A. S.; Mohamed, Sondos A.; Abd El-Khalek, Samah

doi:10.21608/jppp.2006.235239

LEUCOKININ II A NEUROPEPTIDE HORMONE AFFECTING BIOLOGICAL AND BIOCHEMICAL ACTIVITIES OF THE EGYPTIAN COTTON LEAFWORM Spodoptera littoralis (BOlSD.)

Document Type : Original Article

Authors

¹ Economic Entomology Department, Fac.Agric.,Cairo Univ.,Giza, Egypt

² Plant Protection Research institute, ARC, Dokki. Giza, Egypt

10.21608/jppp.2006.235239

Abstract

The insect neuropeptide, leucokinin it was injected into larvae of the cotton
leafworm Spodoptera littoraiis(Boisd.) to investigate the inﬂuence on development,
digestive enzyme release and heamolymph main component. One injected dose of
(2x166 to 4x10'aM) of leucokinin ll into the 5"" instar larvae induced prolongation in
pupal period in all experimental groups, while it had no effect on the timing of larval
ecdysis and length of feeding period. Also leucokinin ll caused a great reduction in
pupal weight, adult longevity, oviposition period, fecundity and fertility. A significant
increase in larval mortality 66.66 to 86.66% was observed. Leucokinin ll inhibited the
release of digestive. protease, amylase, trehalase and invertase. A significant
reduction was obtained in total protein level, whereas total carbohydrate and total lipid
levels were significantly increased in dose dependent manner.