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Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/19/2002 Publication Date: 1/2/2002 Citation: Mckenzie, C.L. 2002. Effect of tomato mottle virus (tomov) on bemisia tabaci biotype b (homoptera: aleyrodidae) oviposition and adult survivorship on healthy tomato. Florida Entomologist. 2002. v. 85. 85(2): p. 367-368. Interpretive Summary: The population dynamics of the sweetpotato whitefly, Bemisia tabaci (Gennadius) biotype B (= silverleaf whitefly, Bemisia argentifolii Bellows & Perring) are driven by seasonal climatic conditions, natural enemies (including entomopathogens), host-plant interactions, and IPM practices. Physiological disorders and the spread of geminiviruses associated with whitefly infestations in Florida vegetables are becoming increasingly important limitations to grower profitability. The effect of plant viruses on the reproductive potential of the vector is key to understanding geminivirus epidemiology and developing effective control measures. The objective of this study was to determine the effect of tomato mottle virus (ToMoV) on whitefly oviposition and survival rates on healthy tomato. Whiteflies carrying ToMoV deposited significantly more eggs (40 percent) than nonviruliferous whiteflies when provided a healthy tomato host. However, there was no significant difference between virus-infected and nonviruliferous whiteflies for the number of adults emerged or the proportion of those adults surviving from the egg stage. In the present study, whiteflies were well adapted to the host plant, either with or without ToMoV. This suggests adaptation to the host plant and virus by the vector could override any adverse effect the virus had on host plant physiology. Insect adaptation to the host-plant is a critical factor that should be considered on a host-by-host basis when evaluating insect biology and vector-host-plant interactions for polyphagous insect species. Technical Abstract: Th effect of plant viruses on the reproductive potential of the whitefly (WF) vector, Bemisia tabaci biotype B, is key to understanding geminivirus epidemiology and developing effective control measures. The objective of this study was to determine the effect of tomato mottle virus (ToMoV) on WF oviposition and survival rates on healthy tomato. In each experiment, one male and one female adult WF from healthy or ToMoV infected WF colonie were confined in clip cages attached to the leaf of a healthy tomato plant. After 48 hours, adult WF were removed and eggs were counted. Experiments were repeated five times. In the last two experiments, progeny from cohorts used in the oviposition clip cage experiments were used to include survival to adult emergence which was evaluated 30 days after egg lay to ensure that all viable WF had emerged. WF infected with ToMoV deposited significantly more eggs (40 percent) on healthy tomato leaves than nonviruliferous whiteflies. There was no significant difference between virus-infected and nonviruliferous WF for the number of adults emerged or the proportion of those adults surviving from the egg stage. There was no significant correlation between the number of eggs deposited per female and progeny survival rates on healthy tomato for WF infected with or without the virus. In the present study, WF were well adapted to the host plant, either with or without ToMoV. This suggests adaptation to the host plant and virus by the vector could override any advese effect the virus had on host plant physiology. Insect adaptation to the host plant is a critical factor that should be considered on a host-by-host basis when evaluating insect biology and vector-host-plant interactions for polyphagous insect species. |
