Studies On Probing And Feeding Behavior Of B And Zhejiang Non-B Biotypes Of Bemisia Tabaci (Gennadius) On Three Types Of Host Plant

Bemisia tabaci(Gennadius) was one of the important pests in tropical,subtropical regions and adjacent temperate zone(Mound and Halsey,1978;Oliveira et al., 2001). With transportation of flowers and other plants,Bemisia tabaci had spread widely throughout the world since 1980s. It hadbeen a serious problem all over the world. The annual economic lossoverran three hundred million dollars (De Barro et al.,1997). In ourcountry, Bemisia tabaci broke out and aggravated yearly. Their damage wasrampant in local areas and it resulted in no harvest. Bemisia tabaci hadbecome important pest of the economic crops, such as vegetables, cottonand flowers. Moreover, it had the developing trend .Bemisia tabaci belongs to piercing sucking insects. Their damagemethod and feeding behavior have consanguineous relationship. Thisexperment researched the differences of feeding behavior in three types ofplants of B and Zhejiang non-B biotypes. The main technology was EPG ,the probing and feeding behavior in free condition was assistant method.The intention of this experiment was to beat out the resiatant mechanism ofplants and the pests'adaptability to host plants. It would offer academictheory to the management of Bemisia tabaci . The experiment results andelementary production were as follows.1) Through many times of attempt, we summed up a sort of feasibleexperimental method of EPG in Bemisia tabaci. The gluing method ofwhitefly includes carbon dioxide anesthetization(Walker and Perring, 1994),vacuum pump(van Helden and Tjallingii, 2000) and cold plate(Walker andJanssen, 2000). We compared the methods through manipulation and foundthat cold plate method had obvious advantage. 2) Seven probing and feeding waveforms of Bemesia tabaci wererecorded. They were A,C,E,F,G,pd and np waveforms. We had notrecorded B waveform. 3) For B biotype Bemisia tabaci, the adaptive degree was cabbage>summer squash >hot pepper. Cabbage was the most adaptive host plant. In25 individuals, 22 individuals reached phloem and had sustained phloemingestion. Both epidermis, mesophyll layers and phloem had not obviousresistance. In 6h recording of summer squash, only 10 individuals hadsustained phloem ingestion in 25 individuals. Before sustained phloemingestion, probing number was more and percentage of non-probingwaveforms was higher than cabbage. It indicated that epidermis-mesophylllayer had resistant factors. Only 10 individuals had sustained phloemingestion in 19 individuals which reached phloem indicated that phloem hadresistant factors also. These factors baffled the sustained phloem ingestionof Bemisia tabaci. It had strong resistance in hot pepper leaves because only1 individual had sustained sap ingestion. Percentage of whiteflies withphloem phase in 1st probe was low, probing and less than 2min probingnumbers were comparatively high, these indicated that all of the three plantswere not the favourite hostplant. For non-B biotype ZHJ-1 population, the adaptive degree wascabbage> summer squash >hot pepper too. On cabbage leaves, 15 whiteflieshad sustained sap ingestion in 25 individuals. On summer squash leaves, 10whiteflies had sustained sap ingestion in 25 individuals. There was nosusutained phloem ingestion on hot pepper leaves. In all of the three periods,cabbge had higher adaptive degree than others. 4) On cabbage leaves, the individual number of sustained phloem...