Neoseiulus mites as biological control agents against Megalurothrips usitatus (Thysanoptera: Thripidae) and Frankliniella intonsa (Thysanoptera: Thripidae) on cowpea crop: laboratory to field

Authors: ZHANG, YU-FEI - Guizhou University; ZANG, LIAN-SHENG - Guizhou University; GUO, LING-HAO - Guizhou University; Singh, Sukhwinder; WU, SHENG-YONG - Guizhou University; Yang, Xiangbing; TANG, LIANG-DE - Guizhou University

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/9/2024
Publication Date: 5/23/2024
Citation: Zhang, Y., Zang, L., Guo, L., Singh, S., Wu, S., Yang, X., Tang, L. 2024. Neoseiulus mites as biological control agents against Megalurothrips usitatus (Thysanoptera: Thripidae) and Frankliniella intonsa (Thysanoptera: Thripidae) on cowpea crop: laboratory to field. Journal of Economic Entomology. https://doi.org/10.1093/jee/toae118.
DOI: https://doi.org/10.1093/jee/toae118

Interpretive Summary: Thrips, Megalurothrips usitatus and Frankliniella intonsa, have been devastated pests threatening cowpea production in many countries in Africa and China. Current management of these pests relied heavily on conventional synthesized pesticide, causing various issues including environmental contamination. Biological control using Neoseiulus mites for the two thrips species have been little studied and biocontrol programs are environmental friendly with various benefits to consider. To evaluate the potential of Neoseiulus mites as biological control agents for management of the two thrips, scientists from the Guizhou University (Guizhou, China) and USDA-ARS (Miami, Florida, USA) studied the functional responses of two Neoseiulus species, Neoseiulus barkeri and N. californicus, on the two thrips species, and further evaluated the control efficacy of the mites on the thrips in caged trials in the cowpea field. The results showed that both mites species demonstrated type II form of functional response, demonstrating an efficient pattern as predating the two thrips species. Field trials of releasing different densities of the two mite species showing that effective management of the two thrips species were achieved. This study provided useful guidance on using Neoseiulus spp. as biological control agents against M. usitatus and F. intonsa in cowpea production.

Technical Abstract: Megalurothrips (M.) usitatus and Frankliniella (F.) intonsa have been detrimental to cowpea production in many countries. Thrips management relies heavily on insecticides, but alternative methods such as biological control with Neoseiulus predatory mites should be explored. Laboratory experiments were conducted to determine the prey stage preference and functional response of two Neoseiulus species, N. barkeri and N. californicus, towards two thrips species, M. usitatus and F. intonsa, at varying densities and life stages on cowpea. Results showed that Neoseiulus species showed a preference for different life stages of prey. N. barkeri consumed more M. usitatus nymphs, while N. californicus consumed more F. intonsa (second instar nymphs). The functional response of the two Neoseiulus spp. to nymphs of either thrips species was Type II form on cowpea. The higher attack rate coefficient (a') and shorter handling time (Th) values were found on N. barkeri against M. usitatus and a similar trend was found for those in N. californicus against F. intonsa. Field-caged trials were conducted to evaluate the effectiveness of Neoseiulus spp. in controlling two thrips species. The results showed that Neoseiulus spp. was effective in controlling the two thrips species, with varying control efficacies at high or low release rates. The study provided valuable information on using Neoseiulus spp. as biological control agents against M. usitatus and F. intonsa in cowpea crops.