Biodiversity and biocontrol: emergent impacts of a multi‐enemy assemblage on pest suppression and crop yield in an agroecosystem

Ecology Letters - Tập 6 Số 9 - Trang 857-865 - 2003
Bradley J. Cardinale1, Chad T. Harvey1, Kevin Gross1, Anthony R. Ives1
1Department of Zoology, University of Wisconsin-Madison, Madison, WI 53706, USA

Tóm tắt

AbstractThe suppression of agricultural pests has often been proposed as an important service of natural enemy diversity, but few experiments have tested this assertion. In this study we present empirical evidence that increasing the richness of a particular guild of natural enemies can reduce the density of a widespread group of herbivorous pests and, in turn, increase the yield of an economically important crop. We performed an experiment in large field enclosures where we manipulated the presence/absence of three of the most important natural enemies (the coccinellid beetle Harmonia axyridis, the damsel bug Nabis sp., and the parasitic wasp Aphidius ervi) of pea aphids (Acyrthosiphon pisum) that feed on alfalfa (Medicago sativa). When all three enemy species were together, the population density of the pea aphid was suppressed more than could be predicted from the summed impact of each enemy species alone. As crop yield was negatively related to pea aphid density, there was a concomitant non‐additive increase in the production of alfalfa in enclosures containing the more diverse enemy guild. This trophic cascade appeared to be influenced by an indirect interaction involving a second herbivore inhabiting the system – the cowpea aphid, Aphis craccivora. Data suggest that high relative densities of cowpea aphids inhibited parasitism of pea aphids by the specialist parasitoid, A. ervi. Therefore, when natural enemies were together and densities of cowpea aphids were reduced by generalist predators, parasitism of pea aphids increased. This interaction modification is similar to other types of indirect interactions among enemy species (e.g. predator–predator facilitation) that can enhance the suppression of agricultural pests. Results of our study, and those of others performed in agroecosystems, complement the broader debate over how biodiversity influences ecosystem functioning by specifically focusing on systems that produce goods of immediate relevance to human society.

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Tài liệu tham khảo

10.1146/annurev.en.36.010191.003021

10.1016/S0169-5347(03)00011-9

10.1046/j.1570-7458.1998.00310.x

10.1016/S0169-5347(97)01293-7

10.1046/j.1570-7458.2000.00720.x

10.1038/415426a

10.1016/0169-5347(88)90080-8

10.1016/S1049-9644(02)00002-6

10.1007/BF00334664

10.1007/BF02373098

10.1007/s004420000476

10.2307/4425

10.1146/annurev.en.29.010184.000513

10.2307/3546654

10.1086/285853

10.1086/286018

10.1890/0012-9658(1998)079[0704:TROCAC]2.0.CO;2

10.1007/s004420050180

10.1093/ee/13.5.1173

10.1007/BF02515463

10.1086/303269

10.1046/j.1365-2745.2000.00470.x

10.2307/2403041

10.1126/science.264.5165.1581

10.1006/bcon.1996.0029

10.1146/annurev.en.34.010189.002123

10.1126/science.1064088

10.1890/0012-9658(1998)079[2143:PPPIEP]2.0.CO;2

10.1890/1051-0761(1999)009[0378:FFSPTC]2.0.CO;2

10.1038/40849

Mackauer M., 1986, Ecology of Aphidophaga, 347

Mooney H.A., 1995, Global Biodiversity Assessment, 275

10.1146/annurev.es.20.110189.001501

10.1890/1051-0761(2001)011[1224:BCIDAS]2.0.CO;2

10.1146/annurev.ento.43.1.421

10.1007/BF00317517

SAS, 1996, Statistical Analysis System. Version 8.0 for Windows

10.2307/3546733

10.1016/S0169-5347(98)01437-2

10.2307/2404218

10.1890/0012-9658(2001)082[0705:GPDBCB]2.0.CO;2

10.1890/0012-9658(2003)084[0091:IBSAGN]2.0.CO;2

10.1603/0046-225X-29.6.1173

10.1641/0006-3568(2001)051[0235:MFATSO]2.0.CO;2

Swift M.J., 1996, Functional Roles of Biodiversity: A Global Perspective, 261

10.1146/annurev.ento.47.091201.145240

10.1126/science.285.5429.893

10.1073/pnas.94.5.1857

10.1303/aez.2001.399

10.1017/S000748530003282X

10.1046/j.1461-0248.2002.00331.x

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Ecology Letters

Tập 6 Số 9

857-865

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