Automated computed tomography based parasitoid detection in mason bee rearings.

In recent years, insect husbandry has seen an increased interest in order to supply in the production of raw materials, food, or as biological/environmental control. Unfortunately, large insect rearings are susceptible to pathogens, pests and parasitoids which can spread rapidly due to the confined nature of a rearing system. Thus, it is of interest to monitor the spread of such manifestations and the overall population size quickly and efficiently.

Constitutive and induced insect resistance in RNAi-mediated ultra-low gossypol cottonseed cotton.

Background: Besides fibers, cotton plants also produce a large amount of seeds with a high oil and protein content. The use of these seeds is restricted by their high contents of the terpenoid gossypol, which is harmful to humans and livestock. Using a genetic engineering approach, "Ultra-low gossypol cottonseed" (ULGCS) plants were produced by knocking down an enzyme that catalyzes the formation of a precursor of gossypol.

Cotton Defense Induction Patterns Under Spatially, Temporally and Quantitatively Varying Herbivory Levels.

In its defense against herbivores, cotton ( sp.) relies in part on the production of a set of inducible, non-volatile terpenoids. Under uniform damage levels, allocation of induced cotton terpenoids has been found to be highest in youngest leaves, supporting assumptions of the optimal defense theory (ODT) which predicts that plants allocate defense compounds to tissues depending on their value and the likelihood of herbivore attack.

Interaction of transgenic and natural insect resistance mechanisms against Spodoptera littoralis in cotton.

Background: Insect-resistant transgenic plants that express insecticidal Cry proteins from Bacillus thuringiensis (Bt) are grown on millions of hectares worldwide. While these proteins are efficient in controlling key lepidopteran pests, not all pests are affected and the development of resistance in target pests is always a concern. These shortcomings could be addressed by exploiting the natural insect resistance of cotton, especially inducible terpenoids such as gossypol.

Aphid honeydew quality as a food source for parasitoids is maintained in Bt cotton.

Bt-transgenic cotton has proven to be highly efficient in controlling key lepidopteran pests. One concern with the deployment of Bt cotton varieties is the potential proliferation of non-target pests. We previously showed that Bt cotton contained lower concentrations of insecticidal terpenoids as a result of reduced caterpillar damage, which benefited the aphid Aphis gossypii.

Indirect multi-trophic interactions mediated by induced plant resistance: impact of caterpillar feeding on aphid parasitoids.

Cotton produces insecticidal terpenoids that are induced by tissue-feeding herbivores. Damage by Heliothis virescens caterpillars increases the terpenoid content, which reduces the abundance of aphids. This effect is not evident in Bt-transgenic cotton, which is resistant to H.

Pest trade-offs in technology: reduced damage by caterpillars in Bt cotton benefits aphids.

The rapid adoption of genetically engineered (GE) plants that express insecticidal Cry proteins derived from Bacillus thuringiensis (Bt) has raised concerns about their potential impact on non-target organisms. This includes the possibility that non-target herbivores develop into pests. Although studies have now reported increased populations of non-target herbivores in Bt cotton, the underlying mechanisms are not fully understood.

Olfactory host finding, intermediate memory and its potential ecological adaptation in Nasonia vitripennis.

Associative learning of host-associated chemical cues was studied in Nasonia vitripennis, a parasitoid of fly pupae in nests of hole-nesting birds. When females encountered a fly pupa and performed one sequence of host recognition behaviour including drilling the ovipositor into the host in the presence of the artificial odour furfurylheptanoate (FFH), they were afterwards arrested by FFH in olfactometer experiments. The response vanished after 4 days and could be blocked after 3 days by feeding wasps with ethacrynic acid prior and after the training.