Agroecological basis for the design of biotechnological traps based on Isaria fumosorosea for the biological control of Bemisia tabaci in strawberry crops

Isaria fumosorosea is an entomopathogenic fungus that is used as a control alternative for nymphs and adults of Bemisia tabaci. Currently there are some commercial products, however, in greenhouse or field, these do not reach the levels of control as in the laboratory because the viability of the spores decreases as a result of the conditions of application of these products in situ. The objective of this work is to implement, through agroecological data, a system of biotechnological traps based on I. fumosorosea to increase the control efficiency mainly of adults of B. tabaci in strawberry greenhouses. One way to quantify the degree of infestation of a crop is the use of yellow traps, likewise to determine the spatial distribution of adults. The Taylor method [(1984). Assessing and interpreting the spatial distributions of insect populations. Annual Reviews of Entomology, 29, 321–357) was used in five different strawberry cultivation models, finding aggregate and regular distributions. Finally, once the crop model with the highest degree of infestation was selected, the designed traps were tested and mortalities were obtained between 50% and 90% in both the laboratory and the greenhouse. The biotechnological traps based on I. fumosorosea both in the laboratory and in the greenhouse had statistically the same effect as those used under the traditional method used in the field that is aspersion; therefore, this alternative method of application can be a tool important for the biological control of this pest.     

Host plants influence susceptibility of whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) to the entomopathogenic fungus Isaria fumosorosea (Hypocreales: Cordycipitaceae)

We quantified the tritrophic effect of host plant on the susceptibility of the sweetpotato whitefly Bemisia tabaci (Genn.) to a fungal pathogen in the laboratory. Second-instar whiteflies reared on cucumber, eggplant, tomato and bean plants for six generations were exposed to conidial suspensions of Isaria fumosorosea isolate IF-1106. Our results did not detect differences in response (proportional survival or median lethal time, LT₅₀ days) among insect populations derived from different plants that were treated with 10⁷ conidia/ml. However, at concentrations ≤ 5×10⁶ conidia/ml, whiteflies reared on bean and tomato died significantly more quickly (i.e. LT₅₀ of 4–5 days) compared with cucumber and eggplant reared populations (5–7 days). Bean and tomato-reared populations were also more susceptible to mycosis (LC₅₀ ≈ 6 × 10⁵ conidia/ml) compared with those reared on cucumber (1.9 × 10⁶ conidia/ml) and eggplant (1.5 × 10⁶ conidia/ml). A separate study confirmed that this differential response of whitefly populations to I. fumosorosea was not explained by differences in deposition rate of conidia on leaf surfaces (i.e. a dosage effect). Our findings show that host plants affect the pathogenicity and virulence of a herbivore pathogen, but depend on the rate of exposure (inoculum) applied.     

Joint action of the entomopathogenic fungus Isaria fumosorosea and four chemical insecticides against the whitefly Bemisia tabaci

The strain IfB01 of Isaria fumosorosea (Paecilomyces fumosoroseus) is a promising myco-insecticide candidate for control of Bemisia tabaci. Joint action of strain IfB01 and four chemical insecticides [spirotetramat (Spi), acetamiprid (Ace), imidacloprid (Imi) and thiamethoxam (Thi)] against the whitefly B. tabaci was evaluated using the cooperative virulence index (c.f.). Substantial synergistic actions were found in the mixtures of IfB01 conidia with Spi, Imi and Thi 2–4 days after treatment. The greatest synergism was recorded in the mixture of IfB01 (2.5 × 10⁶ conidia/L) and Imi (12.5 mg/L), which had a c.f. value of 184 at day 3 after treatment. Furthermore, the shorter LT₅₀ values recorded in mixtures indicated that effectiveness improved when the conidia were applied with the chemical insecticides. However, no substantial synergisms were recorded with Ace and from day 5 onwards.     

Effect of Isaria fumosoroseus on mortality and fecundity of Bemisia tabaci and Plutella xylostella

Abstract Entomopathogenic fungi have been used recently for the management of whitefly (Bemisia tabaci) and diamondback moth (Plutella xylostella). In previous studies, Isaria fumosoroseus has shown some potential to control these insect pests. In this paper, the effects of I. fumosoroseus (strain PF01-N4) on the mortality, fecundity and other life table parameters were observed under laboratory conditions. As a first step, the susceptibility of second instars of B. tabaci and P. xylostella was examined in dose-response experiments, which was followed by the studies on the effect of I. fumosoroseus on reproduction. Both B. tabaci and P. xylostella, were susceptible to I. fumosoroseus having median lethal concentration values of 1.10 × 10⁴ and 0.48 × 10⁴ conidia/mL after 12 and 11 days treatment, respectively. The fungal infection significantly reduced the longevity and fecundity of B. tabaci. At 1 × 10⁷ conidia/mL, a minimum average longevity of 9 days was observed as compared to 16.3 days for the control. Similar results were also observed in P. xylostella with an average longevity of 5.6 days as compared to 17.68 days in the control. In case of reproduction, the number of progeny produced by B. tabaci and P. xylostella decreased with an increase in conidial concentration, with the average values of 83.67 and 26.85, 10.92 and 225.51, 112.08 and 31.02 eggs/female for control, 1 × 10⁴ and 1 × 10⁷ conidial/mL, respectively. There was a significant effect of I. fumosoroseus on intrinsic rate of natural increase.     

Conidia production by Isaria fumosorosea on solid substrates and its pathogenicity towards Bemisia tabaci

Large amounts of conidia must be recovered to use Isaria fumosorosea as a biological control agent. Aerial conidia are mass-produced in solid substrate culture. Conidia obtained from growth on different substrates must be similar in quantity and quality (viability, purity and virulence). In the present work, several solid substrates were evaluated: rice, sorghum, sugarcane, corncob, plantain and wheat (derived from the production of Trichogramma sp.) to find alternatives that are economical and available in different regions. The highest conidia production was obtained on rice, plantain and corncob substrates, which yielded 5.33 × 10⁹ conidia/g, 5.24 × 10⁹ conidia/g and 4.8 × 10⁹ conidia/g substrate, respectively. At concentrations of 1 × 10⁷ conidia/mL, the mortality rates obtained with conidia developed on rice, plantain and corncob substrates were 98%, 97% and 88%, respectively. The lethal concentration 50 (LC₅₀₎ values of conidia obtained from rice and plantain were 7.2 × 10⁴ conidia/mL and 5.1 × 10⁴ conidia/mL, respectively.     

玫烟色棒束孢Pr1酶活力、Pr1酶基因表达量与其毒力的相关性

丝氨酸弹性凝乳蛋白酶Pr1是一类能高效降解昆虫体壁蛋白的重要酶,其活力与虫生真菌的毒力有很大的关系。探索玫烟色棒束孢不同菌株Pr1酶活力、Pr1蛋白酶基因表达量与毒力的相关性对该菌的应用具有重要的意义。文中采用专一性短肽底物Suc-Ala-Ala-Pro-Phe-pNA和荧光定量PCR分别测定了玫烟色棒束孢不同菌株的Pr1酶活和Pr1基因的表达量,并采用坡塔喷雾法测定了供试菌株对桃蚜的毒力。结果表明:不同供试菌株Pr1蛋白酶活力与其毒力的线性回归方程为y=3.64x+0.62,R~2=0.432,两者呈正相关;供试菌株Pr1酶活力、Pr1基因表达量与毒力的回归方程为y=0.236+10.833x_1–0.039x_2 (x_1=Pr1酶活力,x_2=Pr1基因表达量),R~2=0.568,说明线性拟合方程能很好地反映原始数据;序列相关系数D-W为2.444,在0.05水平上相关显著,表明Pr1酶活力、Pr1基因表达量对毒力有显著影响;VIF=12.705表明Pr1酶活力、Pr1基因表达量存在中度多重共线性。因此建议将Pr1蛋白酶的酶活力和Pr1基因表达量作为菌株毒力筛选时的重要指标。     

温湿度对玫烟色棒束孢IF‐1106菌株孢子萌发及对烟粉虱致病力的影响(英文)

B型烟粉虱Bemisia tabaci Gennadius是一种重要的世界性农业害虫。玫烟色棒束孢Isaria fumosorosea是防治烟粉虱的一种重要的虫生真菌。对不同温度(20、23、26、29、32℃)、不同湿度(53%、65%、75%、85%、95%)下玫烟色棒束孢IF‐1106菌株分生孢子萌发及其对烟粉虱的致病力进行了测定。结果表明:温度对孢子的萌发有显著影响,26℃时孢子萌发率最高。当相对湿度低于75%时,孢子不萌发或萌发率较低;当相对湿度为85%–95%时,孢子萌发率显著升高。26℃时,烟粉虱2龄若虫的累计死亡率最高。随着相对湿度增大,病菌的致病力增强。当相对湿度为53%–95%时,烟粉虱2龄若虫累计死亡率从54.55%增加到88.89%。玫烟色棒束孢的致病力与孢子萌发率呈正相关,但温度比相对湿度对其影响更明显。结果表明,玫烟色棒束孢IF‐1106菌株侵染烟粉虱的最佳条件是温度26℃和相对湿度大于85%。     

印楝素的杀虫活性及其对烟粉虱的驱避作用

印楝素(azadirachtin)被认为是最有发展前景的植物源杀虫剂。文章主要介绍印楝素对昆虫的接触驱避、产卵驱避、拒食、毒杀、降低生殖力、生长调节等作用及其作用机理。同时也论述印楝素对烟粉虱Bemisia tabaci(Gennadius)寄主选择、产卵、孵化、若虫发育的影响。     

Effects of starvation and oviposition activity on the reproductive physiology of the sweet potato whitefly, Bemisia tabaci

Abstract. We examined the effects of starvation and oviposition on the reproductive physiology of the sweet potato whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae). In a first set of experiments, females were starved as well as denied the opportunity to oviposit. The combined amounts of vitellogenin and vitellin per female increased by 69% when they were removed from plants for 24 h, egg load increased two-fold in approximately 4.5 h. The lipid content, on the other hand, decreased significantly over an 8 h perod. Thus, vitellogenin synthesis and the formation of mature eggs do not seem to be limited by the lack of nutrient intake or the ability to oviposit. In a second set of experiments, females were restricted to either young leaves of melon plants (Cumis melo), that are preferred oviposition sites, or to old melon leaves, that are non-preferred oviposition sites. At the end of the experiment, females on the old leaves contained significantly higher amounts of vitellogenins and vitellins than females confined to young leaves. These comparisons were made relative to body weight. The data also indicate that females accumulated both vitellogenins and lipids when confined to old leaves, but did not do so on young leaves. These results are consistent with the hypothesis that females of B. tabaci explicitly discriminate against older leaves for oviposition. We argue that examinations of changes in egg load or the combined vitellogenin and vitellin content that accompany oviposition can provide better insights into the oviposition behaviour of B. tabaci.     

玫烟色棒束孢侵染对小菜蛾幼虫体内不同酶活的影响

在实验室条件下,测定了昆虫病原真菌玫烟色棒束孢Isaria fumosorosea的侵染对小菜蛾Plutella xylostella3龄幼虫体内酚氧化酶(PO)和不同抗氧化酶类,包括超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢(CAT)及谷胱甘肽S-转移酶(GSTs)活力的变化。结果表明,玫烟色棒束孢侵染小菜蛾3龄幼虫后,体内PO、SOD、POD、CAT和GSTs活力均受到明显的影响。其中感病小菜蛾幼虫体内的PO活力始终高于同期未感染的小菜蛾幼虫,当接菌40h时,酚氧化酶活力达到最大37.4U/g,为对照的2.6倍,而SOD、POD、CAT和GSTs活力在感病前期明显高于对照,接菌40–48h各种酶活力均达到最大,当接菌56h酶活力开始下降,64h时酶活力均明显低于对照。可见玫烟色棒束孢的侵染严重干扰了小菜蛾幼虫体内正常的生理活动。     

Effect of Eugenia winzerlingii Extracts on Bemisia tabaci and Evaluation of its Nursery Propagation

The development of plant-derived products to control Bemisia tabaci Genn. (Hemiptera: Aleyrodidae) is an urgent need for production of horticultural crops. Plant extracts and essential oils of several species of the genus Eugenia (Myrtaceae) have shown insecticidal activity. In southern Mexico, leaf extracts from Eugenia winzerlingii showed nematicidal effect but its insecticidal properties have not been explored. Therefore, the objective of this study was to evaluate the insecticidal effect of aqueous and organic extracts from E. winzerlingii leaves on B. tabaci egg, nymph and adult stages, and else to explore its nursery propagation. Then, extracts of this species were obtained by maceration with different polarity solvents. Bioassays were carried out on Capsicum chinense leaves. Mortality assays showed that aqueous and total crude ethanol (TCE) extracts necrosed the eggs (LC50 = 0.21% w/v and 4.68 mg/mL, respectively), whereas hexane, ethyl acetate (ETA), residual ethanol and TCE extracts affected the nymphs (LC50 = 0.25 - 4.85 mg/mL). In adults, oviposition inhibition by free choice assay indicated that TCE and ETA extracts had major activity (EC50 = 14.62 and 27.86 μg/cm2, respectively). On other hand, the sexual and vegetative propagation of E. winzerlingii showed that this species can be easily cultivated by seeds. In conclusion, extracts of E. winzerlingii leaves are highly effective in controlling B. tabaci. TCE extract, in particular, was toxic to three stages of B. tabaci. This plant could be a potential alternative to develop a novel botanical insecticide to manage this destructive pest.     

An Isaria fumosorosea SCAR marker for evaluation of soil,insect, and airborne samples

Molecular detection markers are needed for ecological studies of entomopathogenic fungi. In this study, a sequence-characterized amplified region (SCAR) marker of Isaria fumosorosea was used to detect the fungus in soil, insects, and airborne samples. These were artificially added with different fungal conidial concentrations. Specificity and sensitivity were tested with semi-nested PCR using oligonucleotides E-AA/M-CTA₁₂₄ F and E-AA/M-CTA₁₂₄ R for the first amplification and E-AA/M-CTA₁₂₄ F and E-AA/M-CTA₁₀₃ R for the second amplification. Specificity assays showed a specific band of 103 bp for DNA samples from 10 I. fumosorosea strains used. Negative results were observed for DNA samples from other species of Isaria, including I. amoene-rosea, I. farinosa, and Paecilomyces carneus as well as with other entomopathogens such as Metarhizium acridum, M. anisopliae, M. majus, M. flavoviride Type E, and Lecanicillium lecanii. Sensitivity assays showed that the specific SCAR marker detected 10⁴ conidia from I. fumosorosea EH-511/3 that were artificially mixed with soil, from 1 to 10⁴ conidia artificially mixed with Galleria mellonella (Lepidoptera: Pyralidae), and from 10 to 10⁵ conidia in Melinex tape for airborne samples. The marker was also able to detect conidia in airborne samples from cotton wicks in a mini wind tunnel. These SCAR markers for I. fumosorosea had excellent specificity and sensitivity and are relevant tools for ecological studies of this fungus.     

Predation,oviposition and conversion rates of the predacious mite,Neoseiulus californicus (McGregor) consuming different densities of Tetranychus urticae Koch,Bemisia tabaci (Genn.) and Thrips tabaci Lind.

Rates of prey consumption, egg production and prey conversion by the predacious mite, Neoseiulus californicus (McGregor) were estimated at different densities of Tetranychus urticae Koch, Bemisia tabaci (Genn.) and Thrips tabaci Lind. in the laboratory. N. californicus females functionally and numerically responded to the increasing densities of T. urticae nymphs, B. tabaci nymphs and T. tabaci larvae showing Holling’s type II. The maximum mean predation and oviposition rates by the predator females devouring T. urticae, B. tabaci and T. tabaci occurred at 15, 10 and 10 prey individuals/day, respectively, followed by the plateau levels at higher prey densities. N. californicus females exhibited the highest feeding and oviposition on T. urticae nymphs, followed by T. tabaci larvae and B. tabaci nymphs. The predator females showed the highest efficiency in converting the prey into egg progeny at 5 individuals/day of the previous prey species, respectively. T. urticae was the most favourable for N. californicus females, followed by T. tabaci and B. tabaci.     

Characterisation of Isaria fumosorosea isolates and their virulence toward the Diamondback Moth,Plutella xylostella

Some morphological and physiological characteristics of an Isaria fumosorosea isolate with diminished virulence, IFCF01-D, and its parent isolate, IFCF01, were evaluated and laboratory bioassays were performed to assess their virulence against Plutella xylostella. The relationship among these traits and virulence against P. xylostella is discussed. There were no significant differences in conidial viability, spore production and the time required for 50% germination (GT₅₀). Spore viability after incubation for 24 h at 25°C was greater than 98% for both isolates tested. Spore production on potato dextrose agar after 14 days incubation at 25°C was 4.68 × 10⁸ and 4.59 × 10⁸ conidia/mL for IFCF01 and IFCF01-D, respectively. When exposed to high temperatures (40, 45, 50 or 55°C) through a water bath for 10 min, conidial germination ranged from 0.83% to 84.0% for IFCF01 and 0% to 86% for IFCF01-D. Germination rate showed a negative relationship with the exposure temperature for both isolates. The per cent germination of isolate IFCF01 24 h after ultraviolet (UV) radiation (18 W, 240–260 nm) varied from 0% to 92% and 0% to 81% for IFCF01-D. Germination rate and the exposure time exhibited a negative correlation for both isolates tested. Conidial surface hydrophobicity of IFCF01 (60%) was significantly higher than that of isolate IFCF01-D (53%). Subsequently, using the cicada exuviae as the substrate for enzymatic analysis, Pr1 and chitinase activity demonstrated the contrasting virulence traits: higher specific activities for the more virulent IFCF01 and lower enzymatic levels for isolate IFCF01-D.     

Physiological effects of nanosilver on vegetative mycelium,conidia and the development of the entomopathogenic fungus,Isaria fumosorosea

An assessment of the influence of water nanosilver suspension was made at a concentration of 10 mg·L^?1 on biological material (i.e., vegetative mycelium and conidia of Isaria fumosorosea entomopathogen) on a background of the silver nitrate ionic form used. Conidia of I. fumosorosea treated with silver nitrate for more than 168 h were completely deactivated. The application of nanosilver on Isaria hyphae resulted in a quantitative limitation of mycelium growth and its weaker sporulation after culturing compared to the control. The pathogenicity of a conidial suspension obtained from such culturing towards test insects did not diverge from that observed in the standard culture. No obvious toxic effects of nanosilver were observed on I. fumosorosea conidia. Isaria conidia, after exposure to nanosilver over a period between 1 and 800 h, initially demonstrated weaker vegetative mycelium formation in culture on solid medium and, as a consequence, this mycelium often sporulated in a poorer manner. In one case, there was a significant stimulation of the sporulation process for nanosilver treatment before culture for 168 h. Concurrently, conidial suspensions obtained from the culture after exposure of over 168 h to nanosilver exhibited enhanced pathogenicity towards test insects, which may be considered a beneficial phenomenon in terms of the function played by Isaria in the whole environment. The reaction of conidia with nanosilver indicates the deactivation of conidia cells in suspensions and a possibility of selection in increased pathogenicity.     

江苏地区烟粉虱的越冬研究

通过室内模拟寒潮、越冬大棚内虫量观察,以及冬后田间调查,研究江苏地区烟粉虱的越冬状况。结果表明,在0℃以上的环境温度下,72 h内各虫态烟粉虱均不会造成急性致死,在-2℃的环境温度下,1 h内低龄若虫开始死亡,24 h后高龄若虫开始死亡,6 h后卵全部死亡。在-4℃的环境温度下,6 h后烟粉虱所有虫态均全部死亡。在单膜覆盖的大棚内,烟粉虱成虫在-2.5℃的寒潮下全部死亡,在双膜覆盖的大棚内,烟粉虱可以安全越冬。研究认为,在江苏地区,烟粉虱可以在日光温室或双膜覆盖的大棚内越冬,苏南部分地区可以在单膜覆盖的大棚内越冬。     

烟粉虱MEAM1隐种漆酶-1基因全长cDNA克隆、序列分析与组织表达

多酚氧化酶是多种刺吸式昆虫唾液中的关键酶类,可以通过干扰寄主植物正常的氧化还原反应来调控食物来源使其更有利于昆虫本身。昆虫体内的漆酶-1属于多酚氧化酶家族,被认为参与昆虫取食过程中的金属离子代谢、降解植物次生有毒物质以及免疫防御等生理活动。为研究漆酶-1基因在烟粉虱MEAM1隐种Bemisia tabaci Middle East-Asia Minor 1组织中的功能,利用RACE技术首次获得了烟粉虱MEAMI隐种漆酶-1（laccase-1,lac-1）基因的cDNA全长序列,命名为Btlac-1 ( GenBank 登录号： JQ966215）。结果表明,该基因含有一个2 733 bp的开放阅读框,编码910个氨基酸,其编码产物含有3个Cu-oxidase功能域, 属于蓝多铜氧化酶家族成员。同源性比较分析表明,Btlac-1与黑尾叶蝉Nephotettix cincticeps和豌豆蚜Acyrthosiphon pisum的lac-1编码的氨基酸序列一致性达58%。Btlac-1在不同组织和发育时期的转录表达分析表明, Btlac-1在烟粉虱MEAM1隐种中肠中的转录水平最高,显著高于头胸部和腹部组织中,且在各个发育时期均有表达,在成虫期的表达水平较高。该结果为进一步明确lac-1在烟粉虱取食过程的生理作用奠定基础,也为探讨刺吸式昆虫与植物相互作用机制提供理论依据。     

玫烟色棒束孢相容性农药筛选及混用对小菜蛾的防效

为了明确玫烟色棒束孢Isaria fumosoroseus与常用农药的相容性,本研究测定了7种常用农药制剂对玫烟色棒束孢菌丝生长、孢子萌发以及产孢量的影响,测试了相容性较好杀虫剂与玫烟色棒束孢混用对小菜蛾Plutella xylostella Linnaeus的防治效果。结果表明,田间使用浓度下,氯虫苯甲酰胺、双丙环虫酯和四氯虫酰胺对菌丝抑制作用相对较小,田间浓度和亚致死浓度的阿维菌素对菌丝生长具有促进作用。所有供试农药在田间使用浓度下对孢子萌发均具有明显抑制作用,抑制作用随农药浓度降低而减弱,其中噻虫啉和四氯虫酰胺对孢子萌发抑制作用相对较小。所有测试药剂对产孢量具有显著抑制作用,抑制作用随农药浓度降低而减弱,其中噻虫啉和氯虫苯甲酰胺抑制作用较小。玫烟色棒束孢3种浓度（9×107、9×106、9×105个孢子/mL）分别与次亚致死剂量四氯虫酰胺混用对小菜蛾的LT50分别为2.19 d、2.94 d、5.16 d,杀虫速度高于单用相应浓度真菌处理（2.34 d、3.29 d、5.33 d）和四氯虫酰胺单独处理（10.60 d）。综合分析结果表明,低剂量的四氯虫酰胺、噻虫啉和氯虫苯甲酰胺与玫烟色棒束孢相容性相对较好,是田间菌药混用可供选择对象;次亚致死剂量的四氯虫酰胺与真菌混用防控小菜蛾具有协同增效作用。     

The effects of physiological factors and host plant experience on the ovipositional activity of the sweet potato whitefly, Bemisia tabaci

Both egg load and levels of vitellogenin and vitellin increased when Bemisia tabaci Gennadius (Homoptera: Aleyrodidae), were deprived of host plants. These increases resulted in significant increases in rates of oviposition. There was no difference in total fecundity between whiteflies temporarily deprived of hosts and a control treatment that had continuous access to hosts. The results of previous exposure to a preferred host, melon (Cucumis melo), and a non-preferred host, cotton (Gossypium hirsutum), were also examined. B. tabaci deposited significantly more eggs during a 6-h period on melon than on cotton, regardless of host species they were previously confined to. In addition, whiteflies previously exposed to cotton, deposited more eggs than females previously exposed to melon. This higher rate of oviposition resulted in a low egg load as well as lower levels of vitellogenin and vitellin. Conversely, a low rate of oviposition led to high egg load and high levels of vitellogenin and vitellin. Individuals from the same treatment exhibited variation in egg load, which was negatively and significantly correlated with previous oviposition activity. We conclude that the effects of previous host plant exposure on oviposition were, in part, due to behavioral differences that are not related to the reproductive physiology.     

不同品种黄瓜对B型烟粉虱羧酸酯酶活性的影响

采用酶标仪动力学法,比较研究了3个黄瓜品种对B型烟粉虱Bemisia tabaci(Gennadius)羧酸酯酶比活力的影响。结果表明,不同品种黄瓜对B型烟粉虱羧酸酯酶活性具有明显的影响:取食四季秋瓜和22-94RZ的B型烟粉虱羧酸酯酶活性均较高,其比活力最低值分别为对照的1.07倍和1.27倍;取食Deltastar RZ的为最低,其羧酸酯酶比活力最低值仅为对照的0.56倍。取食不同品种黄瓜不同时间,B型烟粉虱羧酸酯酶比活力动态变化趋势不同:取食四季秋瓜、22-94RZ的B型烟粉虱,其羧酸酯酶比活力始终保持被激活状态;取食Deltastar RZ后则处于被抑制状态,但72h后恢复至起始水平,说明B型烟粉虱在Deltastar RZ上具有较强的恢复能力,适应性较好。研究表明羧酸酯酶在B型烟粉虱选择适应寄主过程中应该起着重要作用。