Feeding damage to plants by insect herbivores induces the production of plant volatiles, which are attractive to the herbivores natural enemies. Little is understood about the plant biochemical pathways involved in aphid-induced plant volatile production. The aphid parasitoid Diaeretiella rapae can detect and respond to aphid-induced volatiles produced by Arabidopsis thaliana. When given experi...

The small white butterfly Pieris rapae is one of the most destructive pests of Brassicaceae. Yet little is understood about its genes involved in development. To facilitate research on P. rapae, we sequenced the transcriptome of P. rapae during six developmental stages, including the egg, three larval stages, the pupa, and the adult. In total, 240 million high-quality reads were obtained. De no...

Plants protect themselves against herbivory with a diverse array of repellent or toxic secondary metabolites. However, many herbivorous insects have developed counteradaptations that enable them to feed on chemically defended plants without apparent negative effects. Here, we present evidence that larvae of the specialist insect, Pieris rapae (cabbage white butterfly, Lepidoptera: Pieridae), ar...

The wing-scale morphologies of the pierid butterflies Pieris rapae (small white) and Delias nigrina (common jezabel), and the heliconine Heliconius melpomene are compared and related to the wing-reflectance spectra. Light scattering at the wing scales determines the wing reflectance, but when the scales contain an absorbing pigment, reflectance is suppressed in the absorption wavelength range o...

Response to the alarm pheromone, (E)-beta-farnesene, produced by many species of aphids, was assessed in laboratory bioassays using an aphid pest, Myzus persicae (Sulzer), and its primary endoparasitoid, Diaeretiella rapae (McIntosh). This was done in three separate studies, the first investigating responses of a large number of M. persicae clones carrying different combinations of metabolic (c...

The host specificity of Cotesia rubecula (Marshall) was examined through literature searches, behavioural and ecological observations, and host specificity tests of a South Australian population. The results led to the importation and testing of C. rubecula in quarantine in New Zealand where its specificity to the genus Pieris was confirmed. Introduction of the parasitoid was approved and the s...

1. Host ranges of parasitoid wasps are mediated by behavioural responses to hosts and their environment (infectivity), and development in hosts (virulence). Determinants of host range were measured in Diaeretiella rapae (Hymenoptera: Aphidiidae), which has been described as a generalist that attacks more than 60 species. 2. In northern Colorado, this wasp mainly attacks two hosts: cabbage aphid...

We hypothesized that a parasitoid of an herbivore would be attracted to large rather than small patches of plants that provide food for the herbivore. We conducted experiments to determine whether such parasitoids would be more likely to find and/or less likely to leave large patches of their victims' host plants. We also examined whether prey density (independent of patch size) affects plant f...

Spatial distribution or how abundances vary through space is an important trait of insect populations. Knowledge of the spatial distribution provides a basis for understanding various aspects of population biology including resource exploitation, intraspecific competition or the dynamics of predators and parasitoids. For insect pests, information on the spatial structure of populations may help...