title: Sub-lethal effects of Vip3A toxin on survival, development and fecundity of Heliothis virescens and Plutella xylostella.
abstract: The assessment of sub-lethal effects is important to interpret the overall insecticide efficacy in controlling insect pest populations. In addition to the lethal effect, sub-lethal effects may also occur in exposed insects. Vegetative insecticidal proteins (Vips) have shown a broad spectrum of insecticidal activity against many insect pest species. In this study the sub-lethal effects of the Bacillus thuringiensis vegetative insecticidal toxin Vip3A on the development and reproduction of Heliothis virescens F. and Plutella xylostella L. were evaluated in the laboratory. The results indicated that the sub-lethal concentration of Vip3A increased the duration of the larval and pupal stages as compared with the control treatment for both species. The percent pupation and percent adult emergence were significantly lower for Vip3A-treated insects. The proportion of pairs that produced eggs and the longevity of adults were not significantly different between treatments. H. virescens and P. xylostella treated with Vip3A showed an 11 and 17 % decrease in their intrinsic rate of increase (rm) respectively compared with untreated insects. The results from this study will be helpful to develop the strategy to incorporate Vip 3A containing crops in an integrated pest management programme.
authors.affiliation: Department of Entomology, PMAS-AAU Rawalpindi, Muree Road, Rawalpindi, Pakistan. asim@uaar.edu.pk.|Department of Life Sciences, Imperial College London, Silwood Park campus, Ascot, Berks, SL5 7PY, UK. asim@uaar.edu.pk.
authors.forename: Asim
authors.initials: A
authors.lastname: Gulzar
authors.affiliation: Department of Life Sciences, Imperial College London, Silwood Park campus, Ascot, Berks, SL5 7PY, UK.
authors.forename: Denis J
authors.initials: DJ
authors.lastname: Wright
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000737:chemistry*; D001426:Bacterial Proteins / Q000494:pharmacology*; D005298:Fertility / Q000187:drug effects; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects / Q000254:growth & development / Q000382:microbiology; D008136:Longevity / Q000187:drug effects; D009036:Moths / Q000187:drug effects* / Q000254:growth & development / Q000382:microbiology; D010572:Pest Control, Biological
chemical_list: D001426:Bacterial Proteins; D007306:Insecticides; C447139:Vip3A protein, Bacillus thuringiensis
keywords: Heliothis virescens; Plutella xylostella; Sublethal; Vip3A