Insects are the pre-eminent form of metazoan life on land, with as many as 1018 individuals alive at any one instant and over three-quarters of a million species described. Although it is estimated that there are as many as 14,000 species that are blood feeders, only three to 400 species regularly attract our attention. Some of these are of immense importance to us, as vector-borne diseases still form a huge burden on both the human population and our domesticated animals.

Current paradigms generally assume that increased plant nitrogen (N) should enhance herbivore performance by relieving protein limitation, increasing herbivorous insect populations. We show, in contrast to this scenario, that host plant N enrichment and high-protein artificial diets decreased the size and viability of Oedaleus asiaticus, a dominant locust of north Asian grasslands. This locust preferred plants with low N content and artificial diets with low protein and high carbohydrate content.

The brown planthopper Nilaparvata lugens (Stål) is the most serious pest of rice across the world, especially in tropical climates. N. lugens nymphs and adults were exposed to high temperatures to determine their critical thermal maximum (CTmax), heat coma temperature (HCT) and upper lethal temperature (ULT). Thermal tolerance values differed between developmental stages: nymphs were consistently less heat tolerant than adults.

The brown planthopper Nilaparvata lugens (Stål) is the most serious pest of rice across the world, especially in tropical climates. N. lugens nymphs and adults were exposed to high temperatures to determine their critical thermal maximum (CTmax), heat coma temperature (HCT) and upper lethal temperature (ULT). Thermal tolerance values differed between developmental stages: nymphs were consistently less heat tolerant than adults.

Establishing a direct link between climate change and fluctuations in animal populations through long-term monitoring is difficult given the paucity of baseline data. We hypothesized that social wasps are sensitive to climatic variations, and thus studied the impact of ENSO events on social wasp populations in French Guiana. We noted that during the 2000 La Niña year there was a 77.1% decrease in their nest abundance along ca. 5 km of forest edges, and that 70.5% of the species were no longer present.

Parasitoid disturbance populations in agroecosystems can be maintained through the provision of habitat refuges with host resources. However, specialized herbivores that feed on different host plants have been shown to form host-specialized races. Parasitoids may subsequently specialize on these herbivore host races and therefore prefer parasitizing insects from the refuge, avoiding foraging on the crop.