|Yu, Hao -|
|Gouge, Dawn -|
|Shapiro Ilan, David|
Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 6, 2010
Publication Date: December 1, 2010
Citation: Yu, H., Gouge, D.H., Shapiro Ilan, D.I. 2010. A novel strain of Steinernema riobrave (Rhabditida: Steinernematidae) possesses superior virulence to subterranean termites (Isoptera:Rhinotermitidae). Journal of Nematology. 42:91-95. Interpretive Summary: Among the most economically important subterranean termite species in the US are, Reticulitermes flavipes, and Coptotermes formosanus. Subterranean termites are major global pests of wood structures and wood products. More effective environmentally friendly pest control solutions are needed for these devastating insects. Entomopathogenic nematodes (or beneficial nematodes) are safe and natural biopesticides. In prior studies, compared with other nematode species, the entomopathogenic nematode called Steinernema riobrave strain 355 strain, exhibited a high level of virulence (killing power) to one species of subterranean termite named Heterotermes aureus. However, S. riobrave 355 did not do well in suppressing two other important termite species called Reticulitermes flavipes and Coptotermes formosanus. We hypothesized that other strains of the nematode S. riobrave may possess a high level of virulence to all three termite species. Under laboratory conditions we compared three new strains of S. riobrave, and the 355 strain, for virulence to the three termite species. One of the new strains, called TP, was highly virulent to all the termites. Additional studies are warranted to determine the ability of S. riobrave (TP) to control termites under field conditions.
Technical Abstract: Subterranean termites are major global pests of wood structures and wood products. Among the most economically important subterranean termite species in the US are Heterotermes aureus, Reticulitermes flavipes, and Coptotermes formosanus. In prior studies, the entomopathogenic nematode, Steinernema riobrave strain 355, exhibited a high level of virulence to H. aureus compared with other nematode species. However, S. riobrave 355 was reported to be poorly and only moderately virulent to R. flavipes and C. formosanus, respectively. We hypothesized that other strains of S. riobrave may possess a high level of virulence to all three termite species. Under laboratory conditions we compared three novel strains of S. riobrave (3-8b, 7-12, and TP) with the 355 strain for virulence to H. aureus, R. flavipes, and C. formosanus workers. H. aureus was very susceptible to all the S. riobrave strains, and termites in all nematode treatments were dead after 4 d. The TP strain of S. riobrave caused greater mortality in R. flavipes and C. formosanus compared to the other nematode strains. Specifically, the TP strain caused 75% and 91% mortality in R. flavipes and C. formosanus, respectively, which was more than 300% and 70% higher than the mortality caused by other strains. Additional studies are warranted to determine the ability of S. riobrave (TP) to control the targeted termite species under field conditions.