An insecticidal exclusion method was used to assess the effect of parasitoids on level of infestation by the diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), in cabbage. In field trials conducted at Rietondale, Pretoria, Gauteng Province and Brits, North-West Province, South Africa, a selective organophosphate pesticide, with systemic and contact action, dimethoate, ...

A viral histone H4 (CpBV-H4) is encoded in a polydnavirus, Cotesia plutellae bracovirus. Its predicted amino acid sequence is highly homologous to that of host insect histone H4 except for an extended N-terminal tail containing 38 amino acids with nine lysine residues. Its expression induces an immunosuppression of target insects by suppressing immune-associated genes, presumably through an epi...

Sex pheromones have rarely been studied in parasitoids, and it remains largely unknown how male and female parasitoids locate each other. We investigated possible attraction (and repellency) between the sexes of two braconid wasps belonging to the same genus, the gregarious parasitoid, Cotesia glomerata (L.), and the solitary parasitoid, Cotesia marginiventris (Cresson). Males of both species w...

Insecticide resistance and concomittant field failure to control the diamondback moth (DBM), Plutella xylostella were first recorded in 1968 in Punjab. Studies carried out in different states like Tamil Nadu, Karnataka, Madhya Pradesh, Punjab, indicate that fenvalerate, quilnalphos and monocrotophos resistance are now ubiquitous in Plutella xylostella. In Tamil Nadu, the discriminating dose tec...

Vegetables, cultivated on 4.65 million ha with annual production of 53.5 million t in South and Southeast Asia, are subject to severe yield losses from insect pests and diseases in the tropics. Chemical pesticides account for onethird to one-half of the total mean material input cost for vegetable production in the region. Extensive and inappropriate pesticide use has led to pests developing re...