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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 #217803
Title: NEMATODE PARASITISM REDUCES BOTH THE FEEDING OF FRANKLINIELLA FUSCA AND THE TRANSMISSION OF TOMATO SPOTTED WILT VIRUS

Author
item SIMS, KELLY - UNIVERSITY OF FLORIDA
item FUNDERBURK, JOE - UNIVERSITY OF FLORIDA
item Reitz, Stuart
item BOUCIAS, DRION - UNIVERSITY OF FLORIDA

Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 8/31/2007
Publication Date: 10/25/2007
Citation: Sims, K., Funderburk, J., Reitz, S.R., Boucias, D. 2007. Nematode parasitism reduces both the feeding of frankliniella fusca and the transmission of tomato spotted wilt virus. Meeting Abstract.

Interpretive Summary: Frankliniella fusca (Hinds) is the predominant thrips species found inhabiting and reproducing in peanut (Arachis hypogaea L.) and is one of at least nine thrips species to transmit Tomato spotted wilt virus (TSWV). The entomogenous nematode Thripinema fuscum Tipping & Nguyen, a natural enemy of F. fusca, parasitizes larval and adult populations under field conditions. All known Thripinema species render the host female thrips sterile, thereby potentially suppressing 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 cohorts on leaf discs were recorded daily and digital images were subjected to image analysis. Viral transmission rates were compared daily using a local lesion assay and ELISA. The effects of wing form and gender on virus acquisition and transmission were evaluated. Thripinema fuscum greatly reduced the feeding frequency of male and female F. fusca, and in turn, their persistence for transmitting TSWV. Gender appears to have a significant effect on virus acquisition and transmission, with more females acquiring the virus than males but males being more efficient at transmitting TSWV. Wing form does not appear to influence virus uptake. 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.

Technical Abstract: The tobacco thrips (Frankliniella fusca) is the predominant vector of Tomato spotted wilt virus in peanuts. Scientists with the University of Florida and USDA-ARS-CMAVE are addressing biologically-based management programs for this key pest complex in peanuts. One unique natural enemy of the tobacco thrips is the parasitic nematode Thripinema fuscum. This nematode sterilizes female thrips and thus could limit thrips populations and spread of tomato spotted wilt. 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 by parasitized thrips compared with unparasitized ones. These results provide further evidence of how T. fuscum aids in regulating viruliferous F. fusca pest populations and suggests its potential as a biological control agent for inoculative release in peanut.