B型烟粉虱对寄主转换的适应性

将B型烟粉虱分别从嗜性较强的番茄上转移到嗜性相对较弱的国抗22棉花、泗棉3号棉花和辣椒上, 以及从嗜性较弱的辣椒上转移到嗜性相对较强的番茄、国抗22棉花和泗棉3号棉花上, 观察寄主转移后的F₁代、F₂代、F₃代烟粉虱产卵效应和寄主适应度的变化;将F₄代烟粉虱再转移到原寄主, 观察烟粉虱产卵效应和寄主适应度的恢复情况。结果表明, 烟粉虱在不同嗜性寄主上的产卵效应存在明显的差异。在不同嗜性的寄主之间转移, 烟粉虱的寄主适应度变化趋势不同, 从嗜性较强的寄主转移到嗜好性相对较弱的寄主上, 烟粉虱的寄主适应度迅速下降;从嗜性较弱的寄主向嗜性较强的寄主转移后, 烟粉虱的适应度则会迅速提高。烟粉虱对新寄主的适应速度与其对原寄主和新寄主之间的嗜性差异程度有关, 但一般经过1-2个世代后, 产卵效应会逐渐恢复到烟粉虱在该寄主上的正常水平。从过渡寄主转移到原寄主, 烟粉虱的寄主适应度变化符合一般的寄主转移规律, 但嗜性相对较强的过渡寄主可以刺激烟粉虱提高寄主适应性。     

瓜实蝇对39种寄主适应度的评估

采用绝对寄主适应度(W)和相对寄主适应度(W_r)模型评估了瓜实蝇对39种寄主的适应性表现。结果发现瓜实蝇可以在所有供试寄主上产卵,但其幼虫不能在苹果、牛油果、佛手瓜以及百香果上完成发育,因此共得到35个有效评估值。研究也发现无论是绝对适应度(W)还是相对适应度(W_r)的评估值,都能使35种寄主显著地聚为两类,其中笋瓜、葫芦瓜、南瓜、黄瓜、香瓜为瓜实蝇嗜好寄主,其他30种为普通寄主。综上,瓜实蝇对不同寄主的适应度存在显著的差异,其寄主生态位可能存在着核心的"嗜好寄主"和周缘的"普通寄主",从而在瓜实蝇的寄主适应及寄主扩展中发挥着重要的作用。此外,可利用瓜实蝇对不同寄主适应度的差异来防治该虫,如可在"普通寄主"园区堆积嗜好寄主诱杀瓜实蝇。     

烟粉虱对寄主的选择行为

烟粉虱Bemisia tabaci(Gennadius)成虫对寄主植物选择行为的实验结果表明,烟粉虱是通过植物广谱的绿色气体识别植物材料,并进一步受到绿色的诱导。通过烟粉虱在适宜与非适宜寄主植物上滞留时间的差异,可以看出烟粉虱是通过口针刺探的寄主评估过程逐渐实现寄主偏好性的,存在一个短的时滞。综合来看,烟粉虱的寄主选择是通过嗅觉、视觉和味觉共同参与的一个决策过程,以寄主植物的气味、颜色和质量为线索,逐步定位到适宜的寄主植物上,因此在寄主选择过程中存在很大的可塑性。     

寄主种类、距离和种群密度对烟粉虱扩散的影响

在笼罩条件下,分别以黄瓜、棉花、蕹菜为虫源寄主和诱集寄主,研究寄主植物、空间距离、虫源密度等因子对B型烟粉虱扩散的影响。结果发现,从虫源寄主上扩散的成虫量,与烟粉虱对诱集寄主和虫源寄主的嗜性差异程度有关,诱集寄主相对于虫源寄主的嗜性越强,扩散出来的成虫数量就越多,反之扩散的成虫数量就越少。成虫扩散量与诱集寄主的距离呈负相关,并且诱集寄主的嗜性越强,随着距离的增大,诱集量下降的速率越快。成虫扩散量与虫源种群密度呈正关,但非嗜好寄主上的虫口承载量相对较低,在虫口密度相对较高时,非嗜好寄主上烟粉虱向外扩散的相对量更大。烟粉虱的扩散量与寄主营养状况呈负相关,寄主营养胁迫时,非嗜好寄主上可以获得相对更高的诱集量。     

烟粉虱对不同寄主植物的选择性和适应性测试

为了明确在田间烟粉虱Bemisia tabaci(Gennadius)对不同寄主植物选择性和适应性,本实验在室内用Y型嗅觉仪测定了烟粉虱对13种寄主植物的选择性,随后对田间随机排列种植的这13种寄主植物依照测试结果由强到弱依次拔除(拔除次序为茄子、番茄、黄瓜、辣椒、棉花、茼麻、西葫芦、油菜、花菜、小青菜、莲花白、胡萝卜和苦瓜),每次拔除间隔时间为5 d,结果显示:田间第一次调查的结果与室内选择性测试结果一致;随着最适宜寄主的拔除,烟粉虱成虫数量在与其引诱力相近的一种或几种寄主上的略有增加,而其它植物上却没有大的变化,这表明随着最适宜寄主的拔除,烟粉虱成虫会重新分布,但趋向分布于引诱力相对较强的寄主植物;随着寄主植物的拔除,烟粉虱卵、若虫和蛹在引诱力较强的植株上均有所增加;但西葫芦拔除之后其余植株上烟粉虱卵、若虫和蛹的数量没有明显变化;小青菜拔除后,其余植株上烟粉虱卵、若虫和蛹的数量又有所增加。这表明随着最佳寄主的拔除,烟粉虱会趋向选择于引诱力相对较强的寄主植物产卵,当烟粉虱从嗜好性强的植物转移到嗜好性弱的植物时,产卵适应会滞后于取食适应。但整个实验过程中苦瓜上的烟粉虱上成虫、卵、若虫和蛹的数量均变化不大,苦瓜上的成虫应属偶然分布其上,烟粉虱成虫并不取食苦瓜,苦瓜对烟粉虱有趋避作用。本实验模拟田间种植模式,因此实验结果对田间种植具有指导意义。     

烟粉虱(Bemisia tabaci)的寄主选择性

通过田间系统调查、实验室嗅觉测定、笼内和培养皿内自由扩散观察,对烟粉虱的寄主选择性进行了研究.结果表明,在田间,烟粉虱对不同的寄主植物存在明显的寄主选择性,其中对茄子、花椰菜、黄瓜等植物具有较强的嗜性,而对蕹菜、芹菜、苋菜等植物的嗜性较差;烟粉虱对同一植物的不同品种也有明显的选择性.烟粉虱对寄主植物颜色有明显的选择性,选择结果与烟粉虱对这些寄主的嗜性趋势基本一致.烟粉虱对单株寄主植物的嗅觉反应不敏感,但对植物叶片的乙醇抽提物有明显的嗅觉反应,并表现出较强的寄主选择性.在养虫笼内,烟粉虱从虫源皿向寄主植物自由扩散的过程中,在不同寄主植物和同一植物的不同品种上着落的成虫数量不同,并且在一定的时间范围内,着落在寄主叶片上的虫量还会不断的发生变化.     

寄主植物对B型烟粉虱(Bemisia tabaci)几种主要解毒酶活性的影响

研究测定了棉花、一品红、茄子和番茄4个B型烟粉虱(Bemisia tabaci)种群岐睳A羧酸酯酶、猹睳A羧酸酯酶、乙酰胆碱酯酶和谷胱甘肽S-转移酶活性.结果表明:岐睳A羧酸酯酶活性与猹睳A羧酸酯酶活性比值均大于1,说明B型烟粉虱水解岐睳A的能力高于对猹睳A的水解能力;B型烟粉虱不同寄主种群岐睳A羧酸酯酶、猹睳A羧酸酯酶活性个体分布频率均存在一定差异.B型烟粉虱番茄种群羧酸酯酶活性最高(93.06 mOD/(mg protein·min)),是棉花种群的1.49倍.B型烟粉虱茄子种群乙酰胆碱酯酶活性明显高于其他寄主种群,达极显著差异水平(p＜0.01);茄子种群乙酰胆碱酯酶活性分布频率在＞4U/mg protein区间段的分布高达85%,与其他3个寄主种群分布明显不同.B型烟粉虱茄子种群谷胱甘肽S-转移酶活性最高,与其他3个寄主种群间的差异达极显著水平(p＜0.01).上述结果表明,B型烟粉虱主要解毒酶活性在不同的寄主植物上具有一定的生理可塑性.研究有利于揭示该害虫寄主范围广和寄主适应性强的生理生态学基础.     

丽蚜小蜂两个品系寄生行为及对不同寄主植物上烟粉虱的选择性

对丽蚜小蜂两个品系(分别来自北京和美国)寄生烟粉虱的行为和在番茄、黄瓜、甘蓝、茄子及棉花烟粉虱上的发育历期和寄生率进行了研究。结果表明,丽蚜小蜂通过寄主定位、寄主检查、产卵、清扫和梳理等过程对烟粉虱进行寄生,北京品系平均产卵寄生时间为5.0 m in,美国品系为4.2 m in,品系间差异显著。北京品系在棉花烟粉虱上发育历期最短,为17.4 d,甘蓝烟粉虱上发育历期最长,为20.0 d;美国品系在棉花烟粉虱上发育历期最短,为16.3 d,在其余4种寄主植物烟粉虱上发育历期较长(17.3~17.9 d)。2个品系的寄生率均表现为番茄烟粉虱上最高,分别为37.3%和39.0%;棉花次之,分别为32.2%和35.5%;黄瓜上最低,分别为30.2%和29.6%。在寄主植物选择性试验中,2个品系亦表现为寄生番茄烟粉虱时寄生率最高,美国品系为62.7%,北京品系为56.3%,寄生黄瓜烟粉虱时寄生率最低,分别为30.8%和29.0%。     

烟粉虱及温室白粉虱为害后对后续粉虱种群的影响

【目的】分析烟粉虱Bemisia tabaci(Gennadius)或温室白粉虱Trialeurodes vaporariorum(Westwood)为害番茄后对后续温室白粉虱和烟粉虱生长、发育、成虫寿命和繁殖等产生的促进或抑制作用,可为明确寄主植物番茄介导的温室白粉虱-烟粉虱的种间互作,开展粉虱的科学防控提供科学依据。【方法】通过在寄主植物番茄叶片上先将B型烟粉虱或温室白粉虱按不同的顺序、时间间隔分开接种,再系统观察后续接上的两种粉虱生长、发育、繁殖等种群参数的变化。【结果】(1)先期接上烟粉虱对后续温室白粉虱的发育、寿命、产卵量有明显的促进作用;这种作用需烟粉虱的持续诱导,若去掉烟粉虱,其对温室白粉虱的促进作用即消失;先期接上温室白粉虱可缩短后续烟粉虱伪蛹期,但温室白粉虱的持续存在不利于烟粉虱的产卵,且明显降低烟粉虱的内禀增长率和净增殖率。(2)先后在番茄上同时接上温室白粉虱可降低后续烟粉虱的单雌产卵量和雌、雄虫的成虫寿命;先后同时接种烟粉虱却显著地增加了温室白粉虱的单雌产卵量;烟粉虱的提前存在降低了后续烟粉虱单雌产卵量。(3)但两种粉虱之间作用存在着一定的时间滞后性。烟粉虱对温室白粉虱的发育、寿命、产卵量产生的促进作用大约在其卵期后的一段时间才能显现出来;温室白粉虱对烟粉虱伪蛹期的缩短作用也需提前诱导;而温室白粉虱对温室白粉虱的促进作用相当滞后,直到成虫期才显现出来。【结论】B型烟粉虱和温室白粉虱之间可通过寄主番茄产生相互影响,前期烟粉虱为害可显著促进后续温室白粉虱卵和若虫的发育,而前期温室白粉虱为害对烟粉虱的发育不利。     

烟粉虱对四种蔬菜寄主的选择性

为探讨利用趋避作用防治烟粉虱的可能性,进行了3方面试验：1）烟粉虱Bemisia tabaci (Gennadius) 对黄瓜、花椰菜、油菜和莴苣等4种蔬菜的寄主选择性; 2）互喷烟粉虱不同嗜好的寄主植物汁液对其寄主选择性的影响; 3）不同间作方式对黄瓜叶上烟粉虱成虫密度的影响。结果表明,烟粉虱对供试植物有明显的选择性,其嗜好程度为花椰菜>黄瓜>油菜>莴苣。喷施莴苣和花椰菜汁液对烟粉虱的寄主选择性均有显著影响,喷施莴苣原液后,花椰菜和黄瓜上的成虫数分别减少79.6%和87.4%,花椰菜上的着卵量减少84.3%;喷施花椰菜原液后,莴苣上的成虫数和着卵量分别增加82.4%和79.2%,表明不同蔬菜中的内含物是引起烟粉虱对寄主选择性的重要原因。在黄瓜中间作莴苣可使黄瓜叶上烟粉虱成虫数平均减少76.5%;间作花椰菜时,通过诱集作用,也可使黄瓜叶上的成虫数平均降低69.7%。这些结果为利用喷施蔬菜汁液和间作方式控制烟粉虱危害提供了理论依据。     

Feeding Experience of Bemisia tabaci (Hemiptera: Aleyrodidae) Affects Their Performance on Different Host Plants

The sweetpotato whitefly, Bemisia tabaci biotype B is extremely polyphagous with >600 species of host plants. We hypothesized that previous experience of the whitefly on a given host plant affects their host selection and performance on the plants without previous experience. We investigated the host selection for feeding and oviposition of adults and development and survival of immatures of three host-plant-experienced populations of B. tabaci, namely Bemisia-eggplant, Bemisia-tomato and Bemisia-cucumber, on their experienced host plant and each of the three other plant species (eggplant, tomato, cucumber and pepper) without previous experience. We found that the influence of previous experience of the whiteflies varied among the populations. All populations refused pepper for feeding and oviposition, whereas the Bemisia-cucumber and the Bemisia-eggplant strongly preferred cucumber. Bemisia-tomato did not show strong preference to any of the three host palnts. Development time from egg to adult eclosion varied among the populations, being shortest on eggplant, longest on pepper, and intermediate on tomato and cucumber except for the Bemisia-cucumber developed similarly on tomato and pepper. The survivorship from egg to adult eclosion of all populations was highest on eggplant (80-98%), lowest on pepper (0-20%), and intermediate on tomato and cucumber. In conclusion, the effects of previous experience of whiteflies on host selection for feeding and oviposition, development, and survivorship varied depending on host plants, and host plants play a stronger role than previous experience. Preference of feeding and oviposition by adults may not accurately reflect host suitability of immatures. These results provided important information for understanding whitefly population dynamics and dispersal among different crop systems.     

Editorial note

Generalist herbivores can face many challenges when choosing their host plant. This can be particularly difficult if their choice and performance are affected by host experience. Greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), is an invasive generalist herbivore, which has established in year‐round greenhouses at northern latitudes where it cannot overwinter outdoors. It mainly uses crops such as cucumber (Cucumis sativus L.), tomato (Solanum lycopersicum L.), and ornamentals as host plants. However, every summer the insect escapes greenhouses and is exposed to natural vegetation. We evaluated the performance of T. vaporariorum on diverse vegetation outside greenhouses after prolonged experience of greenhouse crops. First, we surveyed the vegetation near infested greenhouses. Development success of the insect differed among wild hosts. We identified five new hosts among 12 plant species that bore pupae and were thus considered suitable as the insect's host plants. Members of the Urticaceae and Onagraceae were the most preferred and frequently inhabited by all insect life stages. The highest abundance of insects occurred in plots with low plant species richness, independent of plant family in these habitats. We then studied experimentally the impact of 1 year of preconditioning to one of three common greenhouse crops, cucumber, tomato, or poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch), on the performance of the preconditioned adults and their progeny on four wild plants. Adults from tomato and poinsettia preferred the novel host species over the species to which they were preconditioned. The whitefly population preconditioned to cucumber was the most fecund on all offered hosts. We conclude that generalist herbivores can have large variation in performance, despite polyphagy, on novel hosts as shown by the variable abundance of T. vaporariorum pupae among outdoor hosts. Furthermore, performance of whiteflies on natural vegetation was affected by experience on greenhouse crops. Based on our observations, we provide insights and recommendations for pest management.     

Influence of plant combinations on population characteristics of Bemisia tabaci biotypes B and Q

In recent years, the dominant biotype of Bemisia tabaci (Gennadius) has shifted from biotype B to Q in many locations of China. Our field monitoring showed that B. tabaci biotype Q could be found on pepper Capsicum frutescens L. while biotype B could not be found on the plant. To study the role of the host plant in the displacement of biotype B by Q, the adult mortality, female fecundity, and adult emergence of both biotypes B and Q on different host combinations were studied using a model system involving pepper and eggplant. The results showed that pepper is not a preferred host for either biotype B or Q adults in comparison with eggplant. The negative impact of pepper to biotype B is, however, much greater than that to biotype Q. Because both the survival rates of the adult whitefly and the average number of emerged adults per female of biotype Q on pepper are higher than that of biotype B, biotype Q showed higher fitness in comparison with biotype B. Our results suggest that the existence and differential impact of a nonpreferred host might affect the population fitness and therefore could play a role in the displacement of biotype B in some regions.     

Vector-virus mutualism accelerates population increase of an invasive whitefly

The relationships between plant viruses, their herbivore vectors and host plants can be beneficial, neutral, or antagonistic, depending on the species involved. This variation in relationships may affect the process of biological invasion and the displacement of indigenous species by invaders when the invasive and indigenous organisms occur with niche overlap but differ in the interactions. The notorious invasive B biotype of the whitefly complex Bemisia tabaci entered China in the late 1990s and is now the predominant or only biotype in many regions of the country. Tobacco curly shoot virus (TbCSV) and Tomato yellow leaf curl China virus (TYLCCNV) are two whitefly-transmitted begomoviruses that have become widespread recently in south China. We compared the performance of the invasive B and indigenous ZHJ1 whitefly biotypes on healthy, TbCSV-infected and TYLCCNV-infected tobacco plants. Compared to its performance on healthy plants, the invasive B biotype increased its fecundity and longevity by 12 and 6 fold when feeding on TbCSV-infected plants, and by 18 and 7 fold when feeding on TYLCCNV-infected plants. Population density of the B biotype on TbCSV- and TYLCCNV-infected plants reached 2 and 13 times that on healthy plants respectively in 56 days. In contrast, the indigenous ZHJ1 performed similarly on healthy and virus-infected plants. Virus-infection status of the whiteflies per se of both biotypes showed limited effects on performance of vectors on cotton, a nonhost plant of the viruses. The indirect mutualism between the B biotype whitefly and these viruses via their host plants, and the apparent lack of such mutualism for the indigenous whitefly, may contribute to the ability of the B whitefly biotype to invade, the displacement of indigenous whiteflies, and the disease pandemics of the viruses associated with this vector.     

不同作物田烟粉虱发生的时空动态

2008～2009年连续2年系统调查了番茄、茄子、棉花、大豆、玉米等寄主植物上烟粉虱种群发生的时间与空间动态。结果表明：不同寄主植物上的烟粉虱成虫及其伪蛹数量有显著性差异,其密度大小依次为：茄子>棉花>番茄>大豆>玉米。其中,在玉米上除了发现极少量的成虫逗留外,没有发现烟粉虱的卵及若虫。在发生的时间序列上,烟粉虱成虫及伪蛹的数量呈现为先逐渐上升后又下降的变化过程,发生高峰期集中在8月5日到8月31日,9月初以后烟粉虱数量慢慢减少。在空间分布上,表现为烟粉虱成虫喜食寄主的上部叶片。统计分析显示,寄主对烟粉虱成虫和伪蛹的数量的影响极显著,而年份对其数量的影响没有显著差异。由此得出的烟粉虱发生和达到高峰的时间,可为烟粉虱预测预报和区域性综合治理提供重要理论依据。     

Evolutionary dynamics of specialisation in herbivorous stick insects

Understanding the evolutionary dynamics underlying herbivorous insect mega‐diversity requires investigating the ability of insects to shift and adapt to different host plants. Feeding experiments with nine related stick insect species revealed that insects retain the ability to use ancestral host plants after shifting to novel hosts, with host plant shifts generating fundamental feeding niche expansions. These expansions were, however, not accompanied by expansions of the realised feeding niches, as species on novel hosts are generally ecologically specialised. For shifts from angiosperm to chemically challenging conifer hosts, generalist fundamental feeding niches even evolved jointly with strong host plant specialisation, indicating that host plant specialisation is not driven by constraints imposed by plant chemistry. By coupling analyses of plant chemical compounds, fundamental and ecological feeding niches in multiple insect species, we provide novel insights into the evolutionary dynamics of host range expansion and contraction in herbivorous insects.     

Biotype-dependent secondary symbiont communities in sympatric populations of Bemisia tabaci

The sweet potato whitefly, Bemisia tabaci, harbors Portiera aleyrodidarum, an obligatory symbiotic bacterium, as well as several secondary symbionts including Rickettsia, Hamiltonella, Wolbachia, Arsenophonus, Cardinium and Fritschea, the function of which is unknown. Bemisia tabaci is a species complex composed of numerous biotypes, which may differ from each other both genetically and biologically. Only the B and Q biotypes have been reported from Israel. Secondary symbiont infection frequencies of Israeli laboratory and field populations of B. tabaci from various host plants were determined by PCR, in order to test for correlation between bacterial composition to biotype and host plant. Hamiltonella was detected only in populations of the B biotype, while Wolbachia and Arsenophonus were found only in the Q biotype (33% and 87% infection, respectively). Rickettsia was abundant in both biotypes. Cardinium and Fritschea were not found in any of the populations. No differences in secondary symbionts were found among host plants within the B biotype; but within the Q biotype, all whiteflies collected from sage harboured both Rickettsia and Arsenophonus, an infection frequency which was significantly higher than those found in association with all other host plants. The association found between whitefly biotypes and secondary symbionts suggests a possible contribution of these bacteria to host characteristics such as insecticide resistance, host range, virus transmission and speciation.     

Fitness of Encarsia sophia (Hymenoptera: Aphelinidae) parasitizing Trialeurodes vaporariorum and Bemisia tabaci (Hemiptera: Aleyrodidae)

Abstract Fitness and efficacy of Encarsia sophia (Girault & Dodd) (Hymenoptera: Aphelinidae) as a biological control agent was compared on two species of whitefly (Hemiptera: Aleyrodidae) hosts, the relatively smaller sweetpotato whitefly, Bemisia tabaci (Gennadius) biotype ‘B’, and the larger greenhouse whitefly, Trialeurodes vaporariorum (Westwood). Significant differences were observed on green bean (Phaseolus vulgaris L.) in the laboratory at 27 ± 2°C, 55%± 5% RH, and a photoperiod of 14: 10 h (L: D). Adult parasitoids emerging from T. vaporariorum were larger than those emerging from B. tabaci, and almost all biological parameters of E. sophia parasitizing the larger host species were superior except for the developmental times of the parasitoids that were similar when parasitizing the two host species. Furthermore, parasitoids emerging from T. vaporariorum parasitized more of these hosts than did parasitoids emerging from B. tabaci. We conclude that E. sophia reared from larger hosts had better fitness than from smaller hosts. Those from either host also preferred the larger host for oviposition but were just as effective on smaller hosts. Therefore, larger hosts tended to produce better parasitoids than smaller hosts.     

Forty‐nine new host plant species for Bemisia tabaci (Hemiptera: Aleyrodidae)

The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a worldwide pest of numerous agricultural and ornamental crops. In addition to directly feeding on plants, it also acts as a vector of plant viruses of cultivated and uncultivated host plant species. Moreover, host plants can affect the population dynamics of whiteflies. An open‐choice screening experiment was conducted with B‐biotype B. tabaci on a diverse collection of crops, weeds, and other indigenous plant species. Five of the plant species were further evaluated in choice or no‐choice tests in the laboratory. The results reveal 49 new reproductive host plant species for B. tabaci. This includes 11 new genera of host plants (Arenaria, Avena, Carduus, Dichondra, Glechoma, Gnaphalium, Molugo, Panicum, Parthenocissus, Trianthema, and Triticum) for this whitefly. All species that served as hosts were acceptable for feeding, oviposition, and development to the adult stage by B. tabaci. The new hosts include three cultivated crops [oats (Avena sativa L.), proso millet (Panicum miliaceum L.), and winter wheat (Triticum aestivum L.)], weeds and other wild species, including 32 Ipomoea species, which are relatives of sweetpotato [I. batatas (L.) Lam.)]. Yellow nutsedge, Cyperus esculentus L., did not serve as a host for B. tabaci in either open‐choice or no‐choice tests. The results presented herein have implications for whitefly ecology and the numerous viruses that B. tabaci spreads to and among cultivated plants.     

Comparison of performance on different host plants between the B biotype and a non-B biotype of Bemisia tabaci from Zhejiang, China

The capacity of the B biotype of the whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), to invade has often been linked to its presumably wider host range than the non‐B indigenous biotypes. However, there are few experimental studies of the relative performance of the B biotype and non‐B biotypes on different host‐plant species. Here, we compared the performance of the B biotype and an indigenous non‐B biotype (China‐ZHJ‐1) of B. tabaci from Zhejiang, China on five commonly cultivated host plants, each from a different family: cotton, tobacco, cabbage, squash, and kidney bean. We also examined the effect of rearing host plants on the performance of the B biotype. Overall, the performance of the B biotype on the five species of plants was much better than that of the indigenous non‐B population. On tobacco, cabbage, and kidney bean, no individuals of ZHJ‐1 completed development to adulthood, whereas the B biotype developed successfully from egg to adult on all three plants. On squash, the B biotype survived better, developed to adulthood earlier and had a higher fecundity than ZHJ‐1. The two biotypes performed more equally on cotton, but even on this plant the B biotype female adults lived nearly twice as long as that of ZHJ‐1 and may have realized a higher life‐time fecundity. The B biotype also showed a substantial capacity to acclimatize to alternative host plants for improved survival and reproduction, on both highly suitable and marginally suitable host plants. We conclude that the host range of the B biotype of B. tabaci may be much wider than those of some indigenous biotypes, and this advantage of the B biotype over the non‐B biotypes may assist in its invasion and displacement of some indigenous biotypes in the field.