Guild-specific patterns of species richness and host specialization in plant-herbivore food webs from a tropical forest.

1. The extent to which plant-herbivore feeding interactions are specialized is key to understand the processes maintaining the diversity of both tropical forest plants and their insect herbivores. However, studies documenting the full complexity of tropical plant-herbivore food webs are lacking.

Low beta diversity of herbivorous insects in tropical forests.

Recent advances in understanding insect communities in tropical forests have contributed little to our knowledge of large-scale patterns of insect diversity, because incomplete taxonomic knowledge of many tropical species hinders the mapping of their distribution records. This impedes an understanding of global biodiversity patterns and explains why tropical insects are under-represented in conservation biology. Our study of approximately 500 species from three herbivorous guilds feeding on foliage (caterpillars, Lepidoptera), wood (ambrosia beetles, Coleoptera) and fruit (fruitflies, Diptera) found a low rate of change in species composition (beta diversity) across 75,000 square kilometres of contiguous lowland rainforest in Papua New Guinea, as most species were widely distributed.

Multiple paternity in a natural population of a wild tobacco fly, Bactrocera cacuminata (Diptera: Tephritidae), assessed by microsatellite DNA markers.

Mating frequency has important implications for patterns of sexual selection and sexual conflict and hence for issues such as speciation and the maintenance of genetic diversity. Knowledge of natural mating patterns can also lead to more effective control of pest tephritid species, in which suppression programmes, such as the sterile insect technique (SIT) are employed. Multiple mating by females may compromise the success of SIT.

Attractiveness of various combinations of colors and shapes to females and males of Bactrocera minax (Diptera: Tephritidae) in a commercial mandarin grove in Bhutan.

Bactrocera minax (Enderlein) (Diptera: Tephritidae) is a major pest of citrus fruit in the region from Nepal through to southwestern China. In tests on wild adult populations of B. minax in a mandarin, Citrus reticulata Blanco, orchard in western Bhutan, both males and females were more attracted to 50-mm-diameter spheres than to 50-mm discs of the same color.

Effect of physiological and experiential state ofBactrocera tryoni flies on intra-tree foraging behavior for food (bacteria) and host fruit.

Using caged host trees on which we manipulated food and oviposition sites, we investigated the foraging behavior of individually-releasedBactrocera tryoni (Diptera: Tephritidae) females in relation to state of fly hunger for protein, presence or absence of bacteria as a source of protein, degree of prior experience with host fruit, and quality of host fruit for oviposition. One aim was to evaluate whether it is immature or matureB. tryoni females that are responsible for initially inoculating host fruit surfaces with "fruit-fly-type" bacteria, the odor of which is known to attractB.