Location: Fruit and Tree Nut ResearchTitle: Laboratory virulence of entomopathogenic nematodes to the sweetpotato whitefly, Bemisia tabaci
|LI, YINPING - Fort Valley State University|
|MBATA, GEORGE - Fort Valley State University|
|Shapiro Ilan, David|
Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/29/2021
Publication Date: 11/28/2021
Citation: Li, Y., Mbata, G., Shapiro Ilan, D.I. 2021. Laboratory virulence of entomopathogenic nematodes to the sweetpotato whitefly, Bemisia tabaci. Journal of Nematology. 53. https://doi.org/10.21307/jofnem-2021-096.
Interpretive Summary: The sweetpotato whitefly is a major insect pest that attacks various crops including vegetables and cotton. Control of the whiteflies relies primarily on chemical insecticides. However, due to pesticide resistance as well as environmental and regulatory concerns, alternative methods of controlling whiteflies must be sought. Beneficial nematodes (also known as entomopathogenic nematodes) may be a viable alternative to chemical insecticides for whitefly control. Beneficial nematodes are small round worms that are used as natural biopesticides. These nematodes do not harm humans or the environment. Our goal was to determine which nematode species is the best at killing sweetpotato whiteflies. In the laboratory, we tested nine different nematode species for their virulence (killing power) to whiteflies. We discovered that the nematode called Heterorhabditis floridensis is the most virulent. Next we will need to test this nematode for the ability to kill whiteflies under greenhouse and field conditions. Our research brings us one step closer to finding a safe alternative method of controlling whiteflies.
Technical Abstract: The sweetpotato whitefly, Bemisia tabaci Middle East-Asia Minor 1 (MEAM1), is a major insect pest on vegetable crops worldwide. Enormous economic losses result from direct and indirect plant damage caused by MEAM1. Biological control using entomopathogenic nematodes (EPN) may be an effective alternative strategy against MEAM1 because this pest has developed resistance to most insecticides. First, nine species of EPN (Heterorhabditis bacteriophora, H. indica, H. georgiana, H. floridensis, Steinernema feltiae, S. carpocapsae, S. riobrave, S. glaseri, and S. rarum) were investigated for virulence against MEAM1 third instar nymphs on snap bean. The percentage mortality of MEAM1 nymphs was evaluated at 3-day post inoculation (dpi). Mortality of MEAM1 nymphs that resulted from application ofThe application of H. bacteriophora (66.31%), H. floridensis (56.38%), S. carpocapsae (54.54%), and S. rarum (57.80%) resulted inwere significantly higher mortality of MEAM1 nymphs than the water control. Subsequently, the four most virulent EPN species, H. bacteriophora, H. floridensis, S. carpocapsae, and S. rarum were evaluated further for virulence against MEAM1 nymphs on snap bean and tomato. The percentage mortality of MEAM1 nymphs was assessed at 3 dpi and 7 dpi. There were no significant differences in MEAM1 nymphal mortality between tomato and snap bean at both 3 dpi and 7 dpi. Compared with other EPN species and water control, the application of H. floridensis caused significantly higher mortality of MEAM1 nymphs (99.25%) at 7dpi. The results indicate that H. floridensis is a very promising biocontrol agent for B. tabaci management.