Spatial and temporal patterns of Frankliniella fusca (Thysanoptera: Thripidae) in wheat agroecosystems

Authors: GOETHE, JAMES - North Carolina State University; Dorman, Seth; WANG, HEHE - Clemson University; KENNEDY, GEORGE - North Carolina State University; HUSETH, ANDERS - North Carolina State University

Submitted to: Journal of Applied Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/21/2022
Publication Date: 2/10/2022
Citation: Goethe, J.K., Dorman, S.J., Wang, H., Kennedy, G.G., Huseth, A.S. 2022. Spatial and temporal patterns of Frankliniella fusca (Thysanoptera: Thripidae) in wheat agroecosystems. Journal of Applied Entomology. 146(5):570-578. https://doi.org/10.1111/jen.12979.
DOI: https://doi.org/10.1111/jen.12979

Interpretive Summary: Thrips (Frankliniella fusca) are an economically important insect pest of many cultivated crops, including cotton, tomatoes, peppers, and tobacco. Previous research has focused on the importance of non-crop weeds for thrips populations when estimating crop infestation risk in the spring. Although weeds play an integral role in population development, other early-season cultivated hosts (e.g., wheat, sage) may also contribute. However, few studies have examined the role of early-season crops as an intermediate host between weeds and sensitive crops that mature later in the season. The goal of this study was to investigate environmental conditions and landscape features associated with thrips populations in winter wheat (Triticum aestivum L.). Exploring these relationships will provide new insights into the drivers of thrips abundance in cultivated crops. In this research we found that immature thrips abundance sampled during the developmental growth stages of wheat after flowering best predicted adult dispersal from the field two weeks later. Cumulative precipitation and the number of precipitation events beginning in the autumn of the prior year were the most important environmental predictors of thrips abundance. At the landscape scale, adult thrips density was negatively related to the area of agriculture, grasslands, and amount of landscape fragmentation. Results of our study provide a basis on which to assess larval thrips and forecast dispersal of this pest from wheat using a head sampling method. At a landscape scale, we show that specific combinations of environmental and landscape variables influence population abundance of thrips in North Carolina row-crop agroecosystems.

Technical Abstract: Frankliniella fusca Hinds (Thysanoptera: Thripidae) is an economically important pest of many cultivated crops, including cotton, tomatoes, peppers, and tobacco. Previous research has focused on the importance of non-crop weeds for F. fusca populations when estimating crop infestation risk in the spring. Although weeds play an integral role in population development, other early-season cultivated hosts (e.g., wheat, sage) may also contribute to the overall population. However, few studies have examined the role of early-season crops as an intermediate host between weeds and sensitive host crops later in the season. The goal of this study was to investigate abiotic conditions and landscape components associated with F. fusca populations in winter wheat (Triticum aestivum L.). Exploring these relationships will provide insight into the drivers of F. fusca. To do this, we conducted a two-year study documenting F. fusca populations during a ten-week period each spring. We sampled immature thrips abundance on wheat heads while concurrently monitoring adult dispersal from the field using yellow sticky cards. Across both years, we found that immature thrips abundance sampled during the milk and dough development stages best predicted adult dispersal from the field two weeks later. Cumulative precipitation and the number of precipitation events beginning in the autumn of the prior year were the most important abiotic predictors of F. fusca abundance. At the landscape scale, adult F. fusca density was negatively related to the area of agriculture, grasslands, and amount of landscape fragmentation. Results of our study provide a basis on which to assess larval thrips and forecast dispersal of this pest from wheat using a head sampling method. At a landscape scale, we show that specific combinations of abiotic and landscape variables influence population abundance of F. fusca in North Carolina row-crop agroecosystems.