African Journal of Agriculture

African Journal of Agriculture ISSN 2375-1134 Vol. 3 (9), pp. 221-233, October, 2016. © International Scholars Journals

Full Length Research Paper

Effect of pests, pollinators and pest-control on crop yield within sub-Saharan Africa

Aaron O. Benjamin1*, David Taylor Gibb2 and Hugh Tom Johnson2,3

1Ministry of Agriculture and Food Security, Lunyangwa Research Station, P. O. Box 59, Mzuzu, Malawi.

2School of Biosciences, Division of Plant and Crop Sciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK.

3Centre for Environmental Geochemistry, Inorganic Chemistry British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK.


Accepted 10 October, 2016


It is essential that the net effect of biodiversity on crop yields is determined; particularly in developing nations, where both increasing food security and reducing biodiversity losses are of high importance. This study modelled the abundance of pests, pollinators and pest-control animals and determined their impact on crop yield within agroecosystems in four rural villages in Malawi. Data on the habitat area, survivorship, fecundity, birthing month and effect on crop yield for 14 animal functional groups were collated through a focused meta-analysis. Using this data, models were created to determine the abundance of each functional group using land cover as the sole input variable; with Participatory Rural Appraisals (PRA) utilised to validate the model prediction. Bees, birds and insects always improved crop yield, whereas monkeys, rodents and large herbivores always result in losses. Three out of four villages experienced a net benefit to crop yield from the animal biodiversity present. We conclude that models derived from meta-analyses appear useful for broadly predicting the local-scale abundance of functional groups and their qualitative impact on crop yield. However, long-term field observations should be conducted to ensure that the PRA values in this study correlate with direct observation.

Key words: Africa, Malawi, Zomba, agriculture, pest, pest control, pollination, pollinator.