Biological control of Polygonum perfoliatum in North America
Polygonum perfoliatum (Polygonaceae: EPPO A2 List) is an herbaceous, terrestrial vine which is native to Asia. It has been introduced as a contaminant of ornamental plants to North America and the EPPO region (see RS 2016/020). In the USA, P. perfoliatum can invade open fields, forest edges and ruderal habitats. Due its growth habit, P. perfoliatum can smother trees and other vegetation which can have a negative impact on their growth and the growth of other species below the canopy. The biological control agent Rhinoncomimus latipes (Coleoptera: Curculionidae) was released against P. perfoliatum in the USA in 2004. The feeding damage of adult weevils and the stem boring larvae can substantially inhibit the growth and reproductive potential of the plant. It is estimated that R. latipes can disperse 4.3 km per year. An experiment was conducted to assess (1) at what height P. perfoliata patches can be detected using aerial images taken from a drone, and (2) the effective release of weevils from a pod attached to an aerial drone. A pod was designed to hold adult weevils and was made using biodegradable polyvinyl alcohol and 3-D printed. The pod’s design enabled it to be attached to the drone and ensured that adults could escape from a 3 mm hole at the top of the pod upon release. An experiment was conducted where the drone was flown at 15 different altitudes to determine the detectability of P. perfoliata patches using aerial images. The results showed P. perfoliata patches were readily detectable on images taken at ≤15 m above the ground. When testing the pod design, more than 98 % of R. latipes successfully escaped from the pod within 24 h after the pod was released. The results suggest that aerial detection of P. perfoliata and deployment of R. latipes for targeted biological control in hard-to-access areas can be accomplished using drone technology.
Sources
Kim J, Huebner CD, Reardon R, Park YL (2021) Spatially targeted biological control of mile-a-minute weed using Rhinoncomimus latipes (Coleoptera: Curculionidae) and an unmanned aircraft system Journal of Economic Entomology 114(5), 1889–1895. https://www.doi.org/10.1093/jee/toab020