Journal of Applied Entomology (2012) 136, 263-270

M.H. Bahar, J.N. Stanley, P.C. Gregg, A.P. Del Socorro and P. Kristiansen (2012)
Comparing the predatory performance of green lacewing on cotton bollworm on conventional and Bt cotton
Journal of Applied Entomology 136 (4), 263-270
Abstract: We compared the survival of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) eggs and larvae on Bt and conventional cotton, in the presence or absence of the generalist predator, green lacewing larvae, Mallada signatus, (Schneider) (Neuroptera: Chrysopidae). In small arenas, green lacewings consumed a similar number of H. armigera eggs (ave. 15.8 ± 1.3 on conventional, 12.6 ± 1.4 on Bt cotton per predator over 24 h) and larvae (ave. 6.8 ± 0.7 conventional, 6.5 ± 0.8 Bt per predator over 24 h) whether on Bt or conventional cotton leaves. Likewise, similar numbers of eggs were consumed by each lacewing larva searching whole plants of either Bt (ave. 15.5 ± 0.6 of 49 over 24 h) or conventional (ave. 13.6 ± 1.1 of 49 over 24 h). On conventional plants over 72 h, survival of H. armigera larvae was 72.8% and decreased to 37.7% when lacewings were present, giving a net consumption rate of 35.1% (8.6 prey per predator over 72 h). On Bt cotton plants, 13.6% of the H. armigera larvae survived after 72 h and this decreased to 1.7% when lacewings were present. This combination of mortality factors operated synergistically. Helicoverpa armigera larvae moved to fruiting structures on conventional or Bt cotton but failed to survive in the squares (young flower buds) when the impacts of Bt and lacewings were combined. The removal of first to second instar H. armigera larvae from squares of Bt cotton by predators has the potential to reduce immediate pest damage and, perhaps more importantly, remove potentially Bt-resistant genotypes.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Md. Habibullah Bahar, Peter C. Gregg, Alice P. Del Socorro

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Helicoverpa armigera	Cotton (Gossypium)
Mallada signata (predator)	Helicoverpa armigera
Bacillus thuringiensis genes in crops (entomopathogen)	Helicoverpa armigera