The applicability of using digital aerial imagery to assess infestations of Lissorhoptrus oryzophilus (Coleoptera: Curculionidae) in Louisiana rice

Remote sensing technologies are being investigated as a means of improving pest management. Research indicates that insect feeding, which reduces crop growth, can be detected using unmanned aerial vehicles, equipped with digital cameras. The rice water weevil (RWW), Lissorhoptrus oryzophilus, is a damaging pest of rice in the United States. This insect impacts nutrient uptake and vegetative growth in rice. Therefore, it is possible that remote sensing, using diagnostic vegetation indices, will be able to accurately quantify RWW presence and damage within rice fields. This two-year study assessed the effectiveness of using digital aerial imagery to predict populations of RWW in small-plot experiments. A DJI Matrice drone was used to capture images of rice plots that had varying levels of RWW infestations. Ground data were taken, using soil-core samples, to ensure accuracy of image analyses. Different vegetation index output values for each plot were correlated with yield values to determine whether they could predict RWW related yield loss. Although data is still being analyzed to determine which flight protocol is most accurate, initial results indicate that digital aerial imagery can be used to differentiate which experimental plots have high RWW infestations. Visible atmospherically resistant index (VARI) was highly correlated with rice yields and may help us understand the impacts RWW has on rice productivity. Potential applications for rice management includes the detection of soil pests, such as RWW, which are difficult to sample commercially. This could greatly improve scouting tactics, resistance management, and lead to precision targeted control tactics.