Bulletin of Entomological Research (1989) 79, 115-121
Clifford S. Gold, Miguel A. Altieri and Anthony C. Bellotti (1989)
The effects of intercropping and mixed varieties of predators and parasitoids of cassava whiteflies (Hemiptera: Aleyrodidae) in Colombia
Bulletin of Entomological Research 79 (1), 115-121
Abstract: Cassava intercropped with cowpea in Colombia had lower numbers of Aleurotrachelus socialis Bondar and Trialeurodes variabilis (Quaintance) per leaf and per plant than did monoculture cassava. These differences persisted for up to six months after harvest of the cowpea. These results are examined in light of the natural enemies hypothesis, which suggests that natural enemies may be favoured in diversified systems, thereby reducing herbivore load. In this regard, the effects of different cropping systems on the whitefly predator Delphastus pusillus (Le Conte) and on the combined action of the parasitoids Amitus aleurodinis Haldeman and Eretmocerus aleyrodiphaga (Risbec) are discussed. D. pusillus displayed a functional response and was more abundant in monocultures than in intercrops. Predator:prey ratios were similar between treatments and so low that predation appeared to have little impact on whitefly numbers. Parasitism levels of Aleurotrachelus socialis were not affected by crop combinations. The data suggest that the activity of the natural enemies does not explain cropping system effects on cassava whitefly populations.
(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): Clifford S. Gold, Anthony C. Bellotti
Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
