Bemisia tabaci biotype B （Bt） and Trialeurodes vaporariorum （Tv） are two whiteflies that often coexist on greenhouse-grown vegetable crops in northern China. The host plant species ofB. tabaci biotype B have been increasing with the spread of its invaded areas. To clarify the effects of plant species on the performances of the two species, amylase and proteinase activity dynamics of both whitefly species were evaluated when their host plant species switched from tomato （preferred by both species, also used as the control） to cotton （pref...
