Adult Lepidoptera are capable of associative learning. This helps them to forage flowers or to find suitable oviposition sites. Larval learning has never been seriously considered because they have limited foraging capabilities and usually depend on adults as concerns their food choices. We tested if Spodoptera littoralis larvae can learn to associate an odor with a tastant using a new classica...

One of our objectives in this investigation is to determine responses of S. littoralis through different developmental stages and generations to secondary metabolic compound presumably gossypol. Gossypol did not significantly show antifeedant except with high concentration (1.7% gossypol in the diet) that gave 10.6, 21.9, and 46.8% for three generations, respectively. Significantly longer larva...

One of our objectives in this investigation is to determine responses of S. littoralis through different developmental stages and generations to secondary metabolic compound presumably gossypol. Gossypol did not significantly show antifeedant except with high concentration (1.7% gossypol in the diet) that gave 10.6, 21.9, and 46.8% for three generations, respectively. Significantly longer larva...

Insecticide and repellent activity of an acetone extract and oil from fresh leaves of Pelargonium x hortorum (cv. Orangesonne) were evaluated against the 2nd and 4th instar larvae of Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae). The oil showed medium toxicity against the 2nd instar and low toxicity against the 4th instar larvae, while the extract showed high significant toxicity at a...

In the context of the study on plant defensive compounds we have isolated the main alkaloid from Hippeastrum puniceum (Amaryllidaceae), 3-O-acetyl-narcissidine (1), and its biological activities tested against two divergent insect species and several plant species. 1 was isolated from the bioactive alkaloidal fraction of H. puniceum. Its chemical structure was established by spectroscopic analy...

Two serine proteases were identified in midgut of 4 instar of Spodoptera littoralis. A trypsin-like one (BApNAhydrolyzing) (TRYP) with a pH optimum at 11.0, and a chymotrypsin esterase-like enzyme (BTEE-hydrolyzing) (CHYMO) with optimum activity at pH 10.0. Serine protease activities were significantly (p < 0.001) inhibited in vitro by soybean trypsin inhibitor (SBI). The incorporation of diffe...