1. 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 , China
SIP

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

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

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

5. 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

6. 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

7. 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

8. 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

9. 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.

10. 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

11. 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

12. 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

13. 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

14. 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)

15. 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)

16. 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 ( )
National Basic Research Program of China (2013CB127604)