Functional response of Franklinothrips vespiformis (Thysanoptera: Aeolothripidae) to eggs and nymphs of Bemisia tabaci (Hemiptera: Aleyrodidae)

Authors: SCHOELLER, ERICH - University Of Georgia; HOGAN, JOSHUA - University Of Florida; McKenzie, Cindy; OSBORNE, LANCE - University Of Florida

Submitted to: Journal of Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/14/2024
Publication Date: 3/5/2024
Citation: Schoeller, E., Hogan, J., Mckenzie, C.L., Osborne, L.S. 2024. Functional response of Franklinothrips vespiformis (Thysanoptera: Aeolothripidae) to eggs and nymphs of Bemisia tabaci (Hemiptera: Aleyrodidae). Journal of Insect Science. 24(2):3,1-9. https://doi.org/10.1093/jisesa/ieae030.
DOI: https://doi.org/10.1093/jisesa/ieae030

Interpretive Summary: The whitely Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a highly polyphagous pest recorded on over 600 plant species, many of which are economically important field and greenhouse crops. Adding to the management complexities arising from its broad host range, is the fact that B. tabaci is a cryptic species complex comprised of over 44 genetically distinct yet morphologically indistinguishable species. The ‘silverleaf’ whitefly, also known as Middle East Asia Minor (MEAM1) or Biotype B, is one of the most economically important species in this complex. We investigate the biological control potential of a predatory thrips (Franklinothrips vespiformis) for whitefly eggs and nymphs be determining the functional response. The maximum daily prey consumption or attack rate for whitefly eggs was calculated as 14, 55, and 108 for first stage larvae, second stage larvae, and adults respectively. The maximum attack rate for nymphs was calculated as 3, 13, and 28 for first stage larvae, second stage larvae, and adults respectively. Results from this study suggest that F. vespiformis larvae and particularly adults are voracious whitefly predators at both low and high prey densities making them very promising biological control agents for B. tabaci.

Technical Abstract: The Middle East Asia Minor 1 (aka “silverleaf”) biotype of Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae) is a greenhouse and field crop pest of global significance. Larvae and adults of the generalist predatory thrips Franklinothrips vespiformis Crawford (Thysanoptera: Aeolothripidae) were assessed as a potential biological control agent for B. tabaci by examining their functional responses to varying densities of eggs and second or third instar nymphs of B. tabaci under laboratory conditions. Ten replicates of each predator and prey stage combination were performed on pepper leaf discs for a 24 h period. Following logistic regression analyses to determine the functional response type exhibited, response parameters were estimated with nonlinear least-squared regression using Roger’s equation. Results showed that F. vespiformis larvae and adults exhibited a type II functional response when feeding on B. tabaci. The handling times (Th) of F. vespiformis larvae and adults ranged from 0.22–1.76'h for B. tabaci eggs and 0.85–9.39'h for B. tabaci nymphs. The attack rate value (a) of F. vespiformis larvae and adults ranged from 0.019–0.22'h-1 for B. tabaci eggs and 0.001–0.08'h-1 for B. tabaci nymphs. The maximum attack rate (T/Th) for eggs was calculated as 13.63, 55.41, and 108.10 for first stage larvae, second stage larvae, and adults respectively. The maximum attack rate for nymphs was calculated as 2.55, 13.16, and 28.18 for first stage larvae, second stage larvae, and adults respectively. Results from this study suggest that F. vespiformis larvae and particularly adults are promising biological control agents for B. tabaci and are efficient predators at both low and high prey densities. Additional studies are necessary to further elucidate its capability in suppressing B. tabaci populations under greenhouse and field conditions.