No evidence for change in oviposition behaviour of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) after widespread adoption of transgenic insecticidal cotton.
Cotton growing landscapes in Australia have been dominated by dual-toxin transgenic Bt varieties since 2004. The cotton crop has thus effectively become a sink for the main target pest, Helicoverpa armigera. Theory predicts that there should be strong selection on female moths to avoid laying on such plants. We assessed oviposition, collected from two cotton-growing regions, by female moths when given a choice of tobacco, cotton and cabbage. Earlier work in the 1980s and 1990s on populations from the same geographic locations indicated these hosts were on average ranked as high, mid and low preference plants, respectively, and that host rankings had a heritable component. In the present study, we found no change in the relative ranking of hosts by females, with most eggs being laid on tobacco, then cotton and least on cabbage. As in earlier work, some females laid most eggs on cotton and aspects of oviposition behaviour had a heritable component. Certainly, cotton is not avoided as a host, and the implications of these finding for managing resistance to Bt cotton are discussed.
School of Biological Sciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia.
M P
MP
Zalucki
School of Biological Sciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia.
J P
JP
Cunningham
CSIRO Ecosystem Sciences, Australian Cotton Research Institute, Narrabri, 2390, NSW.
S
S
Downes
School of Biological Sciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia.
P
P
Ward
School of Biological Sciences, The University of Queensland, St Lucia, Brisbane, 4072, Australia.
C
C
Lange
CSIRO Ecosystem Sciences, Brisbane, 4001, Australia.
M
M
Meissle
CSIRO Ecosystem Sciences, Brisbane, 4001, Australia.
N A
NA
Schellhorn
School of Environment, Griffith University, Nathan, Brisbane, 4111, Australia.
J M
JM
Zalucki
D000818:Animals; D001315:Australia; D001522:Behavior, Animal / Q000187:drug effects*; D001937:Brassica; D018556:Crops, Agricultural / Q000469:parasitology; D005260:Female; D003368:Gossypium / Q000235:genetics*; D009036:Moths / Q000187:drug effects* / Q000235:genetics; D010058:Oviposition / Q000187:drug effects*; D030821:Plants, Genetically Modified; D014026:Nicotiana