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ARS Home » Southeast Area » Gainesville, Florida » Center for Medical, Agricultural and Veterinary Entomology » Insect Behavior and Biocontrol Research » Research » Publications at this Location » Publication #239117
Title: The impact of a parasitic nematode Thripinema fuscum (Tylenchida: Allantonematidae) on the feeding behavior and vector competence of Frankliniella fusca (Thysanoptera: Thripidae)

Author
item SIMS, KELLY - University Of Florida
item FUNDERBURK, JOE - University Of Florida
item Reitz, Stuart
item BOUCIAS, DRION - University Of Florida

Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2009
Publication Date: 7/1/2009
Citation: Sims, K., Funderburk, J., Reitz, S.R., Boucias, D. 2009. The impact of a parasitic nematode Thripinema fuscum (Tylenchida: Allantonematidae) on the feeding behavior and vector competence of Frankliniella fusca (Thysanoptera: Thripidae). Entomologia Experimentalis et Applicata. 132:200-208.

Interpretive Summary: The tobacco thrips, Frankliniella fusca, is one of the most important pests of peanut because it transmits Tomato spotted wilt virus (TSWV). The insect eating nematode Thripinema fuscum is a unique natural enemy of F. fusca that parasitizes larval and adult thrips in the field. To develop biologically-based management programs for the tobacco thrips, scientists with the USDA-ARS Center for Medical, Agricultural and Veterinary Entomology and the University of Florida determined the impact of parasitism by Thripinema fuscum on feeding and TSWV transmission by the tobacco thrips. Laboratory experiments demonstrate that parasitized thrips feed significantly less than unparasitized ones. This reduction in feeding led to a reduction in transmission of tomato spotted wilt virus by parasitized thrips compared with unparasitized ones. These results indicate how T. fuscum aids in regulating viruliferous thrips populations and demonstrate its potential as a biological control agent for tobacco thrips in peanut.

Technical Abstract: Frankliniella fusca (Hinds) (Thysanoptera: Thripidae) is the predominant thrips species found inhabiting and reproducing in peanut (Arachis hypogaea L.) and is one of at least seven thrips species reported to transmit Tomato spotted wilt virus (TSWV). The entomogenous nematode Thripinema fuscum Tipping & Nguyen (Tylenchida: Allantonematidae), a natural enemy of F. fusca, parasitizes larval and adult populations under field conditions. All known Thripinema species render the host female thrips sterile and have the potential to suppress pest populations to near extinction. As a result, secondary spread of TSWV in peanut is reduced. Reduction of the virus in field conditions may also be due to lower transmission rates caused by parasite-induced alterations in host feeding behavior. Therefore, the feeding rates of healthy and parasitized F. fusca male and female cohorts on leaf discs were recorded daily for 10 days and digital images were subjected to image analysis and viral transmission rates were compared daily using DAS-ELISA. Thripinema fuscum reduced the feeding of female F. fusca by nearly 65%, and the ability of females to transmit TSWV by 50%. Potential mechanisms underlying the parasite-induced alterations in feeding behavior and transmission are discussed. Parasitism by T. fuscum significantly reduced male longevity, but female longevity was not affected. These results provide further evidence that T. fuscum aids in regulating viruliferous F. fusca pest populations and suggests its potential as a biological control agent for inoculative release in peanut.