During plaque purification of Spodoptera littoralis nucleopolyhedrovirus in S. littoralis Sl52 cell culture, a deletion mutant virus was isolated. Analysis of the biological properties of this mutant virus revealed an absence of per os infectivity of the occluded virus. Infectivity by injection of the non-occluded (budded) virus is not different between the wild-type and the deleted virus. Rest...

The hypothesis that constitutive and inducible plant resistance against herbivores should trade-off because they use the same resources and impose costs to plant fitness has been postulated for a long time. Negative correlations between modes of deployment of resistance and defences have been observed across and within species in common garden experiments. It was therefore tested whether that p...

The insecticidal activity of the delta-endotoxins of 14 Bacillus thuringiensis strains belonging to 12 subspecies was determined against Pieris brassicae, Heliothis virescens, and Spodoptera littoralis. Larvae of P. brassicae were highly susceptible to purified crystals of strains of B. thuringiensis subsp. thuringiensis and B. thuringiensis subsp. morrisoni, whereas H. virescens responded best...

Arabidopsis thaliana plants fend off insect attack by constitutive and inducible production of toxic metabolites, such as glucosinolates (GSs). A triple mutant lacking MYC2, MYC3, and MYC4, three basic helix-loop-helix transcription factors that are known to additively control jasmonate-related defense responses, was shown to have a highly reduced expression of GS biosynthesis genes. The myc2 m...

The most challenging tasks for phytophagous insects are the location and selection of mates, food sources, and oviposition sites, all crucial for survival and reproduction. To perform these tasks insects rely largely on their sense of smell (olfaction). I address how the insect olfactory system discriminates between components of complex odor mixtures, modulating behavior and fitness. I have st...

Populations of Eruca sativa (Brassicaceae) from desert and Mediterranean (Med) habitats in Israel differ in their defense against larvae of the generalist Spodoptera littoralis but not the specialist Pieris brassicae. Larvae of the generalist insect feeding on plants of the Med population gained significantly less weight than those feeding on the desert plants, and exogenous application of meth...

The antifeedant effect of six cacalolides and six eremophilanolides was tested against the herbivorous insects Spodoptera littoralis, Leptinotarsa decemlineata, and Myzus persicae. The test compounds included several natural products isolated from Senecio madagascariensis (14-isovaleryloxy-1,2-dehydrocacalol methyl ether, 4), S. barba-johannis (13-hydroxy-14-oxocacalohastine, 5; 13-acetyloxy-14...

Aqueous and organic (hexane, chloroform, and methanol) extracts of siliquae, stems and leaves, and seeds of Cleome arabica L. (Brassicales: Capparidaceae) were evaluated in the laboratory for their antifeeding and insecticidal effect on larvae of the cotton leafworm, Spodoptera littoralis (Boisduval) (Lepidoptera, Noctuidae), using a leaf dipping bioassay with castor bean, Ricinus communis L. (...