Effects of a begomovirus on tritrophic interaction of tomato, whitefly Bemisia tabaci and its parasitoid Eretmocerus hayati Yin-Quan Liu Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China SIP15 -2014

Background Information Insect pests Natural enemies Plants Insect vector Plant Virus ？

Background Information Turnip yellow Virus Aphid (Macrosiphum euphorbiae) Parasitoid (Aphidius ervi) Lettuce (Lactuca sativa) Higher larvae mortality Longer developmental times Calvo and Fereres, 2011. Biocontrol, 56(5): 747-757

Study System---Material Solanum lycopersicum cv. Hezuo 903 Insect pests Natural enemies Plants Bemisia tabaci Tomato Yellow leaf curl virus (TYLCV) Eretmocerus hayati

Study System---Experiment design Olfactory Responses of whitefly and parasitoid to tomato plant（Y tube experiments） Foraging behavior of wasp E. hayati （Observer system : Patch residence time and other parameters) Ecological characters of wasps developed in whiteflies on virus-infected tomato or uninfected tomato plant Comparison of leaf trichome density

Main Results: Olfactory response 主要结果 N(n) Olfactory response of whitefly to tomato plant H：Uninfected tomato；V：Virus-infected tomato； HB：Whitefly-infected tomato； VB： Co-infected tomato plant；CK：Control 6

Main Results: Olfactory response 主要结果 N(n) Olfactory response of parasitoid to tomato plant H：Uninfected tomato；V：Virus-infected tomato； HB：Whitefly-infected tomato； VB： Co-infected tomato plant；CK：Control 7

Main Results: Olfactory response 主要结果 Main terpenoids detected in both virus-infected tomato and uninfected tomato (GC-MS) beta.-Myrcene alpha.-Pinene alpha.-Phellandrene 4-Carene alpha.-Caryophyllene Comparison of terpenoids in quantity is ongoing 8

主要结果 Main Results : Foraging behavior Foraging behaviour of Eretmocerus hayati on tomato leaflets (Patches) Treatment No. of patches tested Patch residence time (s) Host handling time (s) Searching time per patch (s) parasitism rate of whiteflies (%) The total handling time per patch Time for parasitizing per patch Time for parasiting a host Feeding time on Uninfected tomato 16 1509.0±191 564.6±92 245.2±37 72. 5±6 497.8±29 944.4±136 33.1±5 Virus infected tomato 2274.9±258 1106.0±179 406.1±62 89.6±9 1132.1±47 1168.8±131 43.8±6 P Values 0.024 0.012 0.034 0.12 0.008 0.88 0.20 Each Patch contains 10 whitefly hosts.

主要结果 Main Results : Parasitism rates Uninfected Plant Virus-infected Plant Parasitism rate （Mean ± SE） of Eretmocerus hayati on Bemisia tabaci reared on uninfected and TYLCV-infected tomato plants 10

主要结果 Main Results : Emergence rates Uninfected Plant Virus-infected Plant Emergence rate （Mean ± SE） of Eretmocerus hayati on Bemisia tabaci reared on uninfected and TYLCV-infected tomato plants 11

主要结果 Main Results : Developmental duration Uninfected Plant Developmental duration(d) Uninfected Plant Virus-infected Plant Developmental time of Eretmocerus hayati on Bemisia tabaci reared on uninfected and TYLCV-infected tomato plants 12

Leaf trichome density (per mm2) Main Results : Leaf trichomes density 主要结果 Leaf trichome density (%) Leaf trichome density (per mm2) Uninfected Plant Uninfected Plant Virus-infected Plant Virus-infected Plant The leaf trichomes density of uninfected and TYLCV-infected tomato plants 13

Conclusion and Discussion TYLCV showed asymmetrical effects to whitefly and wasp in their olfactory responses The wasp preferred the infected plant when tomato was infected by either whitefly or virus The wasp showed no preference between co-infected plants and whitefly-infected plant but prefer to co-infected plants in comparison with virus-infected plant (which implies whitefly infection had stronger effects than virus infection to wasps)

Conclusion and Discussion Parasitoid had longer patch residence time in virus-infected tomato plants, and longer host-handling time. Change of leaf surface feature including leaf trichomes density could be main factors that contribute to the difference. The parasitsm rates, emergence rates and developmental durations of the parasitoid on infected and uninfected plants were similar, (similar suitability of whitefly--- Liu et al., 2009)

Thank you for your attention！ Acknowledgements: Pan, deng Yan, Ting-Ting Zhang, Zhen Liu, Shu-Sheng Li, Yuan-Xi Thank you for your attention！ National Natural Science Foundation of China (31071736) National Basic Research Program of China (2013CB127604)