Manipulation Of Bemisia Tabaci Feeding Behaviors By Cucurbit Chlorotic Yellows Virus

Cucurbit chlorotic yellows virus(CCYV)as a recently reproted virus is transmitted specifically by B and Q biotypes of Bemisia tabaci in a semipersistent manner.Research on this newly reported virus is still at very early stage,so the mechanism of virus transmission by B.tabaci is still unclear.In this study,by using B.tabaci B and Q biotypes,CCYV host cucumber and non-host cotton as experimental materials,we compared feeding behaviors of viruliferous or non-viruliferous whiteflies on cucumber and cotton with the electrical penetration graph(EPG)technique,in attempt to understand the interaction relationship among CCYV,whiteflies and plants,by which to provide a basis for effective management of whiteflies and whitefly-transmitted viruses.The results of this study are as follows.(1)The feeding behaviors of males and females of B.tabaci B and Q biotypes on cucumberViruliferous B biotype had significantly more non-phloem probing and significantly longer salivation time than non-viruliferous B biotype on cucumber(P<0.05).The feeding behaviors of males or females of viruliferous B biotype were different to the whole viruliferous B biotype on cucumber.After infected by CCYV,Q biotype whiteflies had significantly more salivation and probes in phloem(P < 0.05).Compared to non-viruliferous whiteflies,the differences between feeding behaviors of viruliferous B and Q biotypes had reduced.The males of viruliferous B biotype had significantly more number of probes in phloem than males of Q biotypes(P<0.05),while the females of non-viruliferous B biotypes had significantly more number of probes in non-phloem than the females of viruliferous Q biotypes.However,the females of viruliferous Q biotypes had significantly more number of probes in non-phloem than the females of viruliferous B biotypes(P<0.05).(2)The feeding behaviors of males and females of B.tabaci B and Q biotypes on cottonViruliferous B biotype had significantly more non-phloem probing than non-viruliferous B biotype on cotton(P < 0.05).The feeding behaviors of males of viruliferous B biotype were similar to the whole viruliferous B biotype on cucumber,while the females of viruliferous B biotype than females of non-viruliferous B biotype had significantly more non-phloem probing(P< 0.05).Viruliferous Q biotype had significantly more non-phloem probing and duration of phloem than non-viruliferous Q biotype on cotton(P<0.05).The feeding behaviors of male and female of viruliferous Q biotype were similar to the whole viruliferous Q biotype on cucumber.(3)The feeding behaviors of males and females of B.tabaci B and Q biotypes on cucumber and cottonThe non-viruliferous B biotype had significantly more non-phloem probes on cucumber(P<0.05),but had significantly more phloem feeding on cotton(P<0.05).The viruliferous male of B biotype had significantly more phloem feeding than non-viruliferous(P < 0.05).The viruliferous Q biotype had significantly more phloem feeding on cotton than on cucumber(P<0.05),while the non-viruliferous Q biotype had significantly more non-phloem probes and phloem feeding than on cucumber(P<0.05).The males of viruliferous Q biotype had significantly more non-phloem probes on cucumber,but had significantly more phloem feeding on cotton(P<0.05).The females of Q biotype,whether viruliferous or non-viruliferous,had significantly more phloem feeding on cotton than on cucumber(P<0.05).However,the females of viruliferous Q biotype had significantly more numbers of probes and time in non-phloem on cucumber than on cotton(P<0.05).From the experimental results and analysis,we may safely draw the conclusions: The feeding behaviors of B and Q biotypes were manipulated at different degrees after they were infected by CCYV.On cucumber,CCYV promoted feeding of both biotypes of the whitefly,with stronger influence on B biotype than on Q biotype.The influence of CCYV on males of B biotype was stronger than females,but it was stronger for Q biotype females than males on feeding promotion.On cotton,CCYV increased non-phloem probing of B biotype,but enhanced phloem feeding of Q biotype.The promotion of CCYV was stronger on feeding of B biotype males than on females,while the influence of the virus on males and females of Q biotype adults were same,both increasing the phloem feeding.Therefore,CCYV modified the feeding behavior of the vector to enhance transmission of the virus.Manipulation degrees vary with plants,vectors and sexes.