Ecological Entomology (2004) 29, 309-317

Belén Lumbierres, Ramon Albajes and Xavier Pons (2004)
Transgenic Bt maize and Rhopalosiphum padi (Hom., Aphididae) performance
Ecological Entomology 29 (3), 309-317
Abstract: 1. The population abundance and age structure of Rhopalosiphum padi, one of the most common maize aphid species, on transgenic Bt (expressing the Cry1Ab protein) and non-Bt isogenic maize was studied in commercial plots during three crop seasons.
2. A higher density of aphids, particularly alates and young nymphs, occurred in Bt plots at very young maize development stages, corresponding to the settlement period, in the 3 years studied. Possible causes are discussed. After this period, there were no differences between Bt and non-Bt maize.
3. Mortality, development, and reproduction of the offspring of alate forms of R. padi and the offspring of different generations of apterous forms fed with Bt maize were evaluated in the laboratory under controlled conditions.
4. The developmental and pre-reproductive times of the offspring of the first generation of alatae were shorter and the intrinsic rate of natural increase (r_m) higher when aphids fed on Bt maize. The opposite occurs with the offspring of the first generation of apterous mothers, which have lower nymphal and adult mortality, shorter developmental and pre-reproductive times, a higher effective fecundity rate, and greater r_m, when fed on non-Bt maize. The differences in aphid development on the two cultivars may be linked to changes in host-plant quality due to pleiotropic effects of the genetic modification.
5. No differences on aphid mortality, developmental and pre-reproductive times, fecundity, and r_m were found between the offspring of apterous aphids maintained on Bt or non-Bt maize for several generations.
(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): Xavier Pons, Ramon Albajes

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
Research topic(s) for beneficials or antagonists:
non-target effects/fate in environm.

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Rhopalosiphum padi	Maize/corn (Zea mays)	Spain (Canary Is.)
Bacillus thuringiensis genes in crops (entomopathogen)			Spain (continental)
Bacillus thuringiensis Cry1A-toxin (entomopathogen)			Spain (Canary Is.)