Rodent control on small-scale farms a key to food security
Pests can inflict considerable damage on agriculture
of rodent pests on small farms in Africa. Our review highlighted several important findings. We found median crop losses (midpoint of reported losses) attributed to rodent pests were about 15%. This has a significant impact on grain yields and is comparable to losses from cereal stem borers in Africa where much greater investments have been made in control.
But there was a big discrepancy in estimated and reported losses, which highlights the importance of standardising research protocols. Little research has been done to try and find a link between rodent density to crop impact, which limits the setting of reasonable management thresholds on when to control rodents based on their density.
Most importantly, there is a paucity of research investigating effectiveness of control measures on rodent pests.
We made several recommendations that we feel will improve the robustness of rodent pest research. The most important ones included the fact that researchers must adopt a “metaanalytic” framework. For example, they must place their study in the context of prior literature and report on the effect of rodent control, particularly making the comparison between studies and strategies more explicit.
Researchers and funding organisations must be encouraged to establish and fund long-term studies. Once a firm foundation has been established on understanding the drivers of population cycles of the dominant rodent pest species, management and community ecology can be successfully developed.
For example, in some African countries such as Tanzania, researchers showed that rainfall plays an important role in predicting rodent pest outbreaks. This facilitated regional planning to control rodent pests in agricultural areas.
Rainfall predicts outbreaks Researchers must focus more on empirical treatment control studies that test a management action compared to no management actions.
These must be done with suitable replication that investigates management actions on rodent pest populations and associated crop losses. For example, our recent meta-analysis showed avian predators, such as barn owls, can reduce rodent pests.
Last, ecologically based rodent management activities and research should be carried out by multidisciplinary and interdisciplinary teams. In this way research can be sustained over a longer period. – The Conversation
Lourens Swanepoel is associate lecturer at the University of Venda and Steven Belmain is professor of ecology at the University of Greenwich
DEADLY PEST: As crop are endangered by rats, farmers in Kandal province, Cambodia, spend their nights catching the rodents and exporting them to Vietnam for food.