Effect Of TYLCV And Flonicamid On Feeding Behavior Of MED Bemisia Tabaci

Herbivorous insects and host plants have co-evolved for a long time.The emergence of plant viruses has brought more complex effects on herbivorous insects and host plants.Studies have shown that plant viruses affect the feeding behavior of herbivorous insects.Pesticides are currently the most effective measures to prevent and control herbivorous pests.But pesticides often have problems such as low specificity and environmental pollution.It is urgent to select environmentally friendly pesticides to control the host pests and the spreading viruses.Bemisia tabaci(Gennadius),using their needles of mouthparts to feed on plants,is a worldwide invasive pest.It transmits more than 200 plant virus.At present,MED Bemisia tabaci causes serious damage to peppers,tomatoes and the other vegetables.The feeding of Bemisia tabaci induces plants to produce a variety of secondary metabolites,including non-volatile substances and volatile substances.These secondary substances affect the feeding behavior of Bemisia tabaci.The electrical penetration graph(EPG)technology is the highest effective approach for studying how insects transmit plant viruses.This technology is mainly focused on the feeding behavior of insects,through which we could understand the mechanism of virus transmission.In the present study,we determined the effects of tomato yellow leaf curl virus(TYLCV)and flonicamid(pyridine amide insecticide)on the feeding behavior of MED B.tabaci.The main results are shown as following:1.The effects of different treatments of peppers(previously infected and exposure treatment to MED)on the feeding behavior of MED B.tabaci with and without TYLCV have shown that,MED without TYLCV probed more frequently than those with TYLCV in the non-phloem stage of pepper.In contrast,MED with TYLCV probed and fed more in the phloem stage of pepper.We concluded that,TYLCV increases the adaptability of MED to peppers.The research on the feeding behavior of MED showed that previously infected and exposure treatment resulted in a higher feeding efficiency on peppers.It is obvious that the previously infected and exposure treatment significantly improved the feeding ability of the subsequent MED.The interaction between TYLCV with the previously infected and exposure treatments of peppers found that the MED without TYLCV had higher feeding efficiency on the peppers under the control treatments.However,after previously infected and exposure treatment,MED with TYLCV has a higher feeding efficiency on the peppers.Moreover,when TYLCV combined with previously infected and/or exposure treatments of pepper,the feeding efficiency of MED was significantly enhanced on pepper.2.The repellent effect of flonicamid on MED showed that the landing percentage of MED with TYLCV on control tomatoes was significantly higher than that of the tomatoes treated with different concentrations of flonicamid.With the increase of the flonicamid concentration,the percentage of MED landings gradually decreased.3.The feeding behavior of MED on tomatoes changed with 3 different concentrations of flonicamid.The feeding efficiency of MED was significantly lower than that of the control.The higher the flonicamid concentration,the lower the feeding efficiency.We determined that MED transmitted TYLCV to the host tomatoes,and the TYLCV content in tomatoes was significantly lower than control after treatment with 3 different concentrations of flonicamid.However,there was no significant difference in TYLCV content in tomatoes among the three concentrations.The present study aimed to explore the effects of TYLCV and flonicamid on the feeding behavior of MED Bemisia tabaci.In order to clarify the control potential of flonicamid on MED Bemisia tabaci,we compared the effects of different tomatoes treated with different concentrations of flonicamid on the repellent effect against MED whitefly,MED feeding behavior and TYLCV transmission efficiency o by MED whitefly.The present study,to some extent,has offered a theoretical basis for the use of flonicamid on control of MED B.tabaci and TYLCV.