The beet armyworm, Spodoptera exigua (Hubner), has recently become a persistent and explosive pest of cotton in the southeastern United States. It is, however, attacked by a large and diverse complex of beneficial arthropods and pathogens that appear capable of maintaining beet armyworm populations below economically-damaging levels. Disruption of this complex contributes to outbreaks of S. exi...

Spodoptera exigua (Lepidoptera: Noctuidae) is one of the major pests of many crops in Pakistan. Effectiveness of different insecticides was evaluated against field populations of 2 instar larvae of S. exigua under laboratory conditions because in lepidopterous pests resistance is developed in 3 instars. Bioassays were performed through leaf dip method to evaluate the doseand time-mortality resp...

Fertilizer with different ratios of nitrogen (N) to phosphorus (P) can influence crop plant performance and defense against herbivores. Spodoptera exigua is an important agricultural pest that has caused serious economic loss, especially in recent decades. In the present study, we explored effects of different intensities and durations of S. exigua herbivory on host plant biomass and on S. exig...

Shortly prior to death, many species of Lepidoptera infected with nucleopolyhedrovirus climb upwards on the host plant. This results in improved dissemination of viral occlusion bodies over plant foliage and an increased probability of transmission to healthy conspecific larvae. Following applications of Spodoptera exigua multiple nucleopolyhedrovirus for control of Spodoptera exigua on greenho...

The role of salicylic acid (SA) in plant responses to pathogens has been well documented, but its direct and indirect effects on plant responses to insects are not so well understood. We examined the effects of SA, alone and in combination with jasmonic acid (JA), on the performance of the generalist herbivore, Spodoptera exigua, in wild-type and mutant Arabidopsis thaliana genotypes that varie...

Several mutants of the Bacillus thuringiensis Cry1Ca toxin affected with regard to specific activity towards Spodoptera exigua were studied. Alanine was used to replace single residues in loops 2 and 3 of domain II (mutant pPB19) and to replace residues 541-544 in domain III (mutant pPB20). Additionally, a Cry1Ca mutant combining all mutations was constructed (mutant pPB21). Toxicity assays sho...

Insect chemosensory genes have been considered as potential molecular targets to develop alternative strategies for pest control. However, in Spodoptera exigua, a seriously polyphagous agricultural pest, only a small part of such genes have been identified and characterized to date. Here, using a bioinformatics screen a total of 79 chemosensory genes were identified from a public transcriptomic...

Using a comparative approach, the mechanisms involved in maintenance of the transmembrane K+ activity gradients in the larval body-wall muscles of two insects, Phormia terraenovae (Diptera) and Spodoptera exigua (Lepidoptera), have been investigated. Double-barrelled K+-selective microelectrodes were used to obtain simultaneous measurements of intracellular K+ activity and membrane potential, w...

Many parasites enhance their dispersal and transmission by manipulating host behaviour. One intriguing example concerns baculoviruses that induce hyperactivity and tree-top disease (i.e., climbing to elevated positions prior to death) in their caterpillar hosts. Little is known about the underlying mechanisms of such parasite-induced behavioural changes. Here, we studied the role of the ecdyste...

Beet armyworm, Spodoptera exigua (Hübner) is one of the most destructive pests that causes significant losses in crops. Unfortunately, S. exigua have developed resistance toward the majority of insecticides. Synergists may provide an important choice to deal with the resistance problems. Dodecyl dimethyl benzyl ammonium chloride (DDBAC) is a cationic surfactant, which displayed enhancement effe...