Buckwheat (Fagopyrum esculentum): its impact on wireworm development and survival

Abstract

AbstractBuckwheat (Fagopyrum esculentum) is a member of the Polygonaceae family, cultivated as a cover crop to suppress or reduce weeds and improve soil health. In our field studies, buckwheat gave significant potato tuber protection from wireworm damage after two consecutive years of cropping. In this study, we identified the mechanism underlying the beneficial effect of buckwheat on wireworm suppression. Results show high wireworm numbers in buckwheat than other host plants in bioassays conducted under greenhouse and field conditions which reject the hypothesis that buckwheat has antifeedant activity. We found that newly hatched neonate wireworms feeding on either barley or buckwheat plants for 120 days, showed reduced body weight and head capsule size. The larvae feeding on buckwheat were 60% and 30% smaller than the ones feeding on barley. Survival was also impacted with 44% of the neonate larvae surviving on barley plants, and only 15% when feeding on buckwheat roots over 120 days. A similar bioassay with small to medium-sized wireworms showed higher mortality, lower weight gain and smaller head capsule size. Wireworms feeding on buckwheat were deformed and demonstrated irregular growth. In conclusion, this study revealed that buckwheat did not repel wireworms and they chose to feed on the roots despite it not being a good host. Long-term feeding on buckwheat roots caused reduced weight gain, abnormal growth, and reduced survival. This study provided a better understanding of how buckwheat functions as a biopesticide for wireworm control and its potential for use in an IPM program.