吡虫啉胁迫对西花蓟马生长发育及种群性比的影响

为明确吡虫啉持续大量使用对外来入侵害虫西花蓟马Frankliniella occidentalis的影响。本研究通过毒力测定得到西花蓟马室内种群LC_(30)及LC_(50)的两种吡虫啉浓度162 mg/L和171 mg/L,在室内人工气候箱环境下研究了西花蓟马各虫态的发育历期、成虫寿命及性比等相关种群参数。结果表明,西花蓟马未成熟虫期的发育历期在经过吡虫啉处理后相比对照显著缩短(P0.05),且雌性西花蓟马的未成熟虫期明显短于雄性西花蓟马,其中以171 mg/L吡虫啉处理后西花蓟马的雌性种群未成熟虫期发育历期缩短最为明显(P0.05);西花蓟马雄性种群的寿命略长于雌性种群,且171 mg/L吡虫啉处理后雌雄虫寿命与对照相比均显著缩短(P0.05);吡虫啉处理后西花蓟马的平均产卵期低于对照,但单雌产卵量、日均产卵量均显著高于对照,171 mg/L吡虫啉处理后的单雌产卵量和日均产卵量最高(P0.05)。吡虫啉胁迫后,西花蓟马的雌性种群在整个种群中所占比例增速迅速上升,经过125 d(大约5代)之后,雌性种群已经占绝对优势,几乎取代雄性种群,即种群中90%以上均为雌性西花蓟马。西花蓟马雌性种群对吡虫啉的胁迫适应性强于雄性种群,吡虫啉胁迫是造成西花蓟马雌性种群比例迅速升高的主要原因之一,在吡虫啉浓度LC_(30)到LC_(50)胁迫的范围内,随着吡虫啉胁迫浓度的增加,种群中雌性种群所占比例增大。     

在CO_2浓度升高条件下西花蓟马和花蓟马的生长发育及繁殖力比较

为明确大气CO2浓度升高对外来入侵害虫西花蓟马Frankliniella occidentalis及其本地近缘种花蓟马F.intonsa的影响,利用两种CO2浓度(800μL/L vs.400!L/L)的人工气候箱研究了西花蓟马和花蓟马未成熟期的发育历期、累积存活率、单雌产卵量及净生殖率等种群参数。结果表明:在CO2浓度倍增条件下(800μL/L),西花蓟马和花蓟马的非成虫历期显著短于对照CO2浓度(400μL/L)下的种群;花蓟马的累积存活率比对照下降了26.30%(P0.05),而西花蓟马的累积存活率与对照差异不显著;西花蓟马的单雌平均产卵量比对照组增加了4.17粒,而花蓟马的雌成虫寿命、成虫平均单雌产卵量和日均单雌产卵量分别降低了1.31 d、4.83粒和0.56粒(P0.05)。与对照相比,高CO2浓度处理下西花蓟马种群的净生殖率(R0)、内禀增长率(rm)和周限增长率(λ)均显著增加,而平均世代周期(T)、种群加倍时间(t)均明显减少;而花蓟马则相反,其种群的R0、rm和λ均显著降低,T和t均明显长于对照(P0.05)。在相同CO2浓度下,西花蓟马的非成虫虫态历期短于花蓟马;两种蓟马非成虫虫态的不同发育阶段存活率由高至低的顺序相同,依次为:蛹期预蛹期2龄若虫期1龄若虫期。研究结果说明入侵种西花蓟马对未来高CO2浓度大气环境的适应性强于本地种花蓟马。     

西花蓟马对蔬菜寄主的选择性研究

通过西花蓟马在田间不同蔬菜上的种群数量、在室内对不同蔬菜的自由选择和不同蔬菜对西花蓟马生长发育和繁殖的影响等方面,研究了西花蓟马对蔬菜寄主的选择性。结果表明西花蓟马在田间可危害24种蔬菜,但在不同蔬菜上种群数量差异很大,存在明显的寄主选择性,对黄瓜、四季豆、茄子、萝卜和香菜的嗜食度很高,为最适宜寄主,而对番茄、蒜、芹菜等11种蔬菜的嗜食度较低,为非适宜寄主。西花蓟马在室内的自由选择结果表明西花蓟马在7种不同蔬菜上着落的成虫数量和产卵量不同,其选择性为黄瓜＞四季豆＞茄子＞莴苣＞甘蓝＞芹菜＞蒜。不同蔬菜对西花蓟马的发育历期和产卵量有明显的影响,西花蓟马在黄瓜上发育最快,在四季豆上产卵量最高。西花蓟马对蔬菜寄主的选择性在田间的调查结果和室内实验结果基本一致。     

接种番茄斑萎病毒番茄植株对西花蓟马生物学特性的影响

西花蓟马Frankliniella occidentalis(Pergande)是我国的一种重要入侵害虫。本文研究了西花蓟马在番茄3种处理(健康CK、机械接种番茄斑萎病毒MI、机械损伤MD)叶片上的生长发育、存活及种群增长。结果表明:健康、机械接种番茄斑萎病毒、机械损伤叶片上的发育历期依次为12.68、12.99和11.79d。雌雄成虫寿命和雌虫繁殖能力在各处理叶片上差异不显著(P>0.05)。健康、机械接种番茄斑萎病毒、机械损伤叶片上的内禀增长率依次为0.1362、0.1526和0.1292d-1。本研究表明,接种番茄斑萎病毒的番茄叶片未缩短西花蓟马发育历期,也不能延长寿命及提高产卵量,不能明显加速种群数量增长。这意味着番茄斑萎病毒对西花蓟马在番茄叶片上的生物学特性未能产生明显的有利作用。     

吡虫啉对西花蓟马和花蓟马种间竞争及后代发育的影响

本研究采用浸渍饲喂法测得吡虫啉对西花蓟马(Frankliniella occidentalis)和花蓟马(Frankliniella intonsa)的LC50浓度,并选取花蓟马2龄若虫的LC50浓度11.00 mg·L-1作为本试验用浓度,在此浓度胁迫下将2种蓟马以1∶1的种群数量比例用菜豆在同一养虫笼中饲养,进行室内种间竞争试验,测定2种蓟马的生长发育和繁殖力等参数。结果表明:在吡虫啉胁迫下,从25~150 d内西花蓟马与花蓟马种群数量比值不断升高,2种蓟马种内雌性种群数量所占比例均高于雄性种群,且西花蓟马种群中雌性种群所占比例(斜率为6.22)高于花蓟马种群中雌性种群所占比例(斜率为2.68)(P0.05);两种蓟马的未成熟虫期各虫态的发育历期在吡虫啉胁迫下均显著缩短,且西花蓟马的发育历期缩短更为明显(P0.05);在吡虫啉胁迫下西花蓟马种群的存活率、雌雄成虫寿命稍高于花蓟马种群但差异不显著(P0.05),西花蓟马的净生殖率(R0)、内禀增长率(rm)、周限增长率(λ)的值均要高于花蓟马的值;2种蓟马种群内雌雄成虫寿命、平均世代周期(T)和种群加倍时间(DT)与对照相比均显著缩短(P0.05);吡虫啉处理下西花蓟马的平均产卵量、R0、rm、λ值均显著高于对照(P0.05),而花蓟马的平均产卵量、R0、T和DT却显著低于对照。研究表明,在吡虫啉浓度11.00 mg·L-1胁迫下,西花蓟马种群的竞争能力和对吡虫啉胁迫的适应性强于花蓟马种群,蓟马种群内雌性种群的竞争力强于雄性种群,吡虫啉胁迫是加速西花蓟马对花蓟马种群种间取代的重要因子。     

西藏拉萨地区西花蓟马种群生命表及发生动态研究

【目的】明确拉萨地区西花蓟马Frankliniellaoccidentalis的生物学特性和田间动态规律。【方法】建立了该种群的两性生命表,采用黄板诱集成虫的方法调查了日光温室番茄上西花蓟马的周年发生动态。【结果】该种群西花蓟马成虫前期总发育历期为12.54 d,2龄若虫发育历期为5.62 d,占成虫前期发育历期的44.8%,卵能存活到成虫阶段的概率为0.598。雌虫的平均寿命为27.76 d,雄虫为20.2 d。该种群的内禀增长率(r)和净增殖率(R0)分别为0.153/d和22.817。在拉萨日光温室番茄上西花蓟马能够周年发生,种群增长呈"单峰"型,6月中旬至8月上旬为发生盛期。【结论】拉萨地区西花蓟马的2龄若虫期明显较长,日光温室中西花蓟马的最佳防治适期在4月初。     

西花蓟马在6种蔬菜寄主上的实验种群生命表

自西花蓟马Frankliniella occidentalis传入我国后,该虫对蔬菜寄主的危害趋于严重,组建了25℃条件下,西花蓟马在黄瓜、甘蓝、莴苣、茄子、芹菜和大蒜叶片的实验种群生命表,以研究西花蓟马的危害差异性,为西花蓟马的防治提供基础数据。结果表明西花蓟马的生长发育、繁殖和生命表参数等在不同寄主之间有明显差异。西花蓟马在黄瓜上发育最快,其未成熟期为11.43 d,同时在黄瓜上最先开始产卵,产卵前期为1.22 d,在芹菜上发育最慢,为16.11 d。其每雌每天在甘蓝上和莴苣上产卵量最大,分别为2.88粒和2.48粒,在大蒜上最小,为0.77粒;每雌每天产雌率、子代雌性比在甘蓝和莴苣上都大于其他寄主。雌虫寿命在甘蓝上最长(29.06 d)、雄虫寿命在莴苣上最长(13.22 d)。西花蓟马在黄瓜、莴苣、茄子、甘蓝、芹菜和大蒜上的内禀增长力rm值分别为0.1318、0.1228、0.1154、0.1197、0.0860和0.0791;净增殖率R0分别为19.1248、30.8523、17.9322、34.5322、8.9491和8.3536。种群趋势预测指数(I)在甘蓝(34.17)、莴苣(30.09)上明显高于其它寄主,在芹菜(8.00)和大蒜(8.22)上最低。     

东亚小花蝽对西花蓟马的控害能力评价

在实验室条件下,采用编制特定年龄生命表的方法,获得东亚小花蝽Orius sauteri和西花蓟马Frankliniella occidentalis的重要种群生物学参数,进而分析评价东亚小花蝽对西花蓟马的控害能力。结果表明：东亚小花蝽的净生殖力（22.6）和内禀增长率（0.1345）均大于西花蓟马（20.2、0.1225）。此外,东亚小花蝽的世代历期（23.17 d）和种群倍增时间（5.15 d）均小于西花蓟马（24.54 d、5.65 d）。另外,东亚小花蝽的单雌平均产卵量（61.8粒）大于西花蓟马（35.4粒）。综合上述研究结果说明,东亚小花蝽的种群扩繁速度大于西花蓟马,且具有控制西花蓟马种群增长的巨大潜力。     

番茄斑萎病毒对多杀菌素抗性西花蓟马发育繁殖和药剂敏感性的影响

【目的】西花蓟马Frankliniella occidentalis (Pergande)是重要的入侵害虫,是番茄斑萎病毒（TSWV）最有效的传播媒介,TSWV对西花蓟马的生长发育有一定的影响。多杀菌素是防治西花蓟马最有效的药剂之一,但已有田间西花蓟马对多杀菌素产生抗药性的报道。TSWV对抗性西花蓟马是否也有影响及程度如何尚不清楚。本研究通过对此问题进行深入研究,以期为进一步了解TSWV对西花蓟马的影响提供依据。【方法】应用特定年龄-龄期及两性生命表的方法,研究用番茄斑萎病毒处理和未处理的多杀菌素抗性和敏感西花蓟马种群的生物学特性;用叶管药膜法测定不同处理种群对3种药剂（多杀菌素、甲氨基阿维菌素苯甲酸盐和虫螨腈）的敏感性变化。【结果】对于抗性品系,TSWV处理后西花蓟马的发育历期缩短,雌成虫寿命和产卵量略高,但与对照组差异不显著(P＞0.05),内禀增长率（r）和净生殖率（R₀）分别为0.0433 d^-1和2.210,显著高于对照组（分别为0.0356 d^-1和1.972）（P ≤ 0.001）。对于敏感品系,TSWV处理后西花蓟马的发育历期缩短,雌雄成虫寿命均显著延长（P ≤ 0.001）,产卵量也略有提高,R₀为4.125,显著高于对照组（3.979）（P ≤ 0.001）。TSWV处理后敏感和抗性西花蓟马对多杀菌素的敏感性没有发生明显变化,对甲氨基阿维菌素苯甲酸盐和虫螨腈的敏感性显著降低。【结论】番茄斑萎病毒对多杀菌素敏感和抗性西花蓟马均有直接有利影响,病毒处理的西花蓟马发育历期缩短,繁殖能力增强,成虫寿命延长,对药剂的敏感性降低。     

乙基多杀菌素和印楝素对西花蓟马生长发育及繁殖的亚致死效应

为探讨乙基多杀菌素和印楝素对西花蓟马的亚致死效应,采用浸叶法确定了它们对西花蓟马2龄若虫的亚致死浓度(LC₂₅),并研究了该浓度下两种生物源农药对西花蓟马生长发育和繁殖力的影响.结果表明: 两种生物源农药亚致死浓度处理对西花蓟马均有不同程度的影响.在两性生殖方式下,乙基多杀菌素对西花蓟马产卵前期、雌成虫寿命和产卵量均无显著影响,但雄成虫寿命显著缩短;印楝素处理后,西花蓟马产卵量显著降低,产卵前期明显延长.在孤雌生殖方式下,不论乙基多杀菌素和印楝素处理,西花蓟马产卵前期均明显延长,但只有印楝素使雌成虫寿命缩短和产卵量显著降低.两种生物源农药对西花蓟马次代各虫态的发育历期影响不同,无论在何种生殖方式下,乙基多杀菌素处理后西花蓟马的未成熟期均明显短于印楝素处理.乙基多杀菌素处理后西花蓟马的内禀增长率(r_m)和周限增长率(λ)均高于对照,而印楝素较对照低.以上结果说明,两种杀虫剂对西花蓟马生长发育和繁殖影响不同,乙基多杀菌素亚致死浓度对西花蓟马种群的增长有一定的刺激作用,而印楝素有明显的抑制作用.两种杀虫剂的影响程度还与西花蓟马的生殖方式有关.     

Transmission of Chrysanthemum Stem Necrosis Virus, a Recently Discovered Tospovirus, by Two Thrips Species

The biological transmission of a recently discovered tospovirus species, Chrysanthemum stem necrosis virus (CSNV), was studied. The transmission capacity of three thrips species ( Frankliniella schultzei , Frankliniella occidentalis and Thrips tabaci ) was tested using a leaf disc assay combined with DAS-ELISA. This capacity was tested with adults which were given an acquisition access period of 16 h on CSNV-infected plants as new-born larvae, up to 8 h old. The virus was efficiently transmitted by F. schultzei (78.1%) and F. occidentalis (65.1%), but not at all by T. tabaci (0.0%). Infection was confirmed in adult thrips; high virus titres were found in 75.9% of F. schultzei and 97.4% of F. occidentalis adults. Although T. tabaci did not transmit CSNV in this study, comparatively low amounts of virus were detected in 75.0% of the tested population. The results obtained showed that F. occidentalis and F. schultzei may be the major vectors of CSNV in Brazil.     

西花蓟马诱导的番茄植株防御反应对B型烟粉虱行为的影响

【目的】明确外来入侵害虫西花蓟马Frankliniella occidentalis (Pergande)取食诱导的番茄植株防御反应对B型烟粉虱Bemisia tabaci (Gennadius) B-biotype行为的影响, 探讨西花蓟马与B型烟粉虱的种间竞争机制。【方法】利用“Y”型嗅觉仪行为分析法、 选择性试验法, 研究了不同处理组合（健康植株CK vs烟粉虱为害植株B、 健康植株CK vs西花蓟马为害植株F、 烟粉虱为害植株B vs烟粉虱和西花蓟马共同为害植株B+F）下, 烟粉虱对不同处理植株的取食行为反应及寄主偏好的差异性, 并利用GC-MS分析了不同处理植株挥发性物质的差异性。【结果】“Y”型嗅觉仪行为分析结果表明, 在CK vs B和CK vs F两个组合中, 烟粉虱雌成虫对健康植株和昆虫为害植株的偏好性差异不显著; 而在B vs B+F组合中, 烟粉虱为害株对烟粉虱雌成虫具有极显著的引诱作用（P<0.01）。选择性试验结果表明, 在CK vs B和CK vs F这两个组合中, 烟粉虱成虫均偏好健康株并喜好在其上产卵（P<0.01）, 在B vs B+F组合中, 烟粉虱成虫偏好烟粉虱单独为害株并喜好在其上产卵（P<0.01）。GC-MS分析结果显示, 本实验收集到9种挥发性物质, 其中有5种烯萜类物质, 其相对含量高达90%以上。与烟粉虱单独为害株相比, 烟粉虱和西花蓟马共同为害株所释放的挥发性物质中, 对烟粉虱具有排斥作用的β-水芹烯显著升高, 而对其具有吸引作用的β-月桂烯却显著减少。【结论】综合分析认为, 西花蓟马诱导的番茄植株防御反应可以显著影响B型烟粉虱的寄主选择行为及产卵选择性。     

Winter and spring abundance of Frankliniella spp. and Thrips tabaci Lindeman (Thysan., Thripidae) on weed host plants in Turkey

Abstract:  The species composition of thrips and abundance of three pestiferous thrips species, Frankliniella occidentalis (Pergande), Thrips tabaci Lindeman and Frankliniella intonsa (Trybom) (Thysan., Thripidae) on weed species during winter and spring time were studied in vegetable production and polycultured areas in the eastern Mediterranean region of Turkey in years 2002 and 2003. Of a total of 61 543 thrips extracted from 8933 samples collected, 77% were adults. F. occidentalis was collected from all of 49 weed species sampled and F. intonsa was detected on 18 plant species between May and June. T. tabaci was collected from 42 of a total of 49 weed species. Immature thrips were extracted from 42 of a total of 49 weed species. Four weed species of a total 35 weed species sampled between April and May in the sampling areas hosted 63% of larvae and approximately 50% of F. occidentalis collected. A total of 23 thrips species was recorded from weeds sampled in this study. F. occidentalis accounted for 83% of a total 47 640 adult thrips collected and followed by low rates of T. tabaci and F. intonsa (9 and 1%, respectively). Melanthrips spp. accounted for 3.54% of total numbers of adult thrips. Flower-inhabiting thrips species and T. tabaci were most abundant on weeds between April and May when the number of weed species in bloom was greatest, then decreased to low levels after May. Most pestiferous thrips on weeds species were collected from vegetable production areas. F. occidentalis was the predominant thrips comprising over 80% in most months in the vegetable grown area. In polycultured area, the composition of adult thrips shifted monthly. While Melanthrips was the more prevailing thrips by rates 53% in February and 81% in March, F. occidentalis was the predominant thrips with 60 to 62% in spring, respectively.     

西花蓟马与烟蓟马药剂敏感性的比较

采用浸叶法比较了外来入侵物种西花蓟马Frankliniella occidentalis(Pergande)与本地物种烟蓟马Thrips tabaci Lindeman对辛硫磷、毒死蜱、高效氯氰菊酯、多杀霉素、甲氨基阿维菌素苯甲酸盐和阿维菌素6种杀虫剂的敏感性。结果显示:西花蓟马对辛硫磷、毒死蜱和多杀霉素的敏感性均比烟蓟马明显要高,而高效氯氰菊酯和阿维菌素对烟蓟马则具有较高的毒力。多杀霉素对西花蓟马和烟蓟马的防治效果最好,在药剂浓度为0.5mg/L时,2种蓟马的校正死亡率均超过90%。     

Bioactivity of carvacrol and thymol against Frankliniella occidentalis and Thrips tabaci

Abstract: Two constituents of essential oils, carvacrol and thymol, were tested for their effects on the feeding activity, oviposition preference and oviposition rate of Frankliniella occidentalis and Thrips tabaci . Given a choice between treated and untreated leaf discs, F. occidentalis avoided ovipositing on leaf discs treated with 1 or 0.1% thymol. In no-choice experiments, 1 and 0.1% thymol and 1% carvacrol resulted in a reduced oviposition rate of F. occidentalis compared with the control. Both constituents caused a slight reduction of the feeding damage of F. occidentalis . 1 and 0.1% carvacrol had a pronounced deterrent effect on the oviposition site selection of T. tabaci . Both constituents served as anti-ovipositants for both thrips species, albeit F. occidentalis was more affected than T. tabaci .     

A Survey of Tospoviruses in Bulgaria

A survey of tospoviruses present in Bulgaria was conducted during three vegetation periods. A total of 258 different virus isolates were obtained from tobacco, tomato, weeds and ornamentals in the open fields and from glasshouses. Virus isolates were identified by inoculation to test plants and serology as Tomato spotted wilt virus (TSWV). No indications were obtained that other Tospovirus species were present in Bulgaria. In addition the transmission ability and efficiency of several Bulgarian populations of Thrips tabaci (Lind.) and Frankliniella occidentalis (Perg.) was determined. The experimental results indicated that Bulgarian TSWV isolates are transmitted with high efficiency by F. occidentalis and that only arrhenotokous and not thelytokouse populations of T. tabaci could transmit TSWV.     

Lack of fitness costs of insecticide resistance in the western flower thrips (Thysanoptera: Thripidae)

The fitness costs of spinosad and acrinathrin resistance was investigated in the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). Fitness studies were conducted on susceptible and resistant strains of F. occidentalis. Resistant females were significantly more fecund (number of eggs per female) than susceptible females. The hatching rate (fertility) for both susceptible and acrinathrin-resistant strains was significantly lower than in the spinosad-resistant strain. Mean developmental time from egg to adult did not differ between thrips populations. Similarly, female longevity did not differ between populations. These data suggest that lack of fitness costs related to insecticide resistance may accelerate the development of insecticide resistance in populations of F. occidentalis from southeastern Spain.     

Genetic Regulation of Liver Microsomal CYP2E1 Activity among Strains of the Viviparous Fishes Poeciliopsis occidentalis and Poeciliopsis lucida

The use of CYP2E1 (cytochrome P4502E1) expression as a biomarker for xenobiotic contamination may be useful, but for full understanding of the response, components of inheritance need to be understood. CYP2E1 expression was examined in P. lucida (M61-31), two strains of P. occidentalis (V87-15 and AV76-7), and their F1, F2, and backcross progeny. Phenotypic expression of CYP2E1 in Poeciliopsis has two distinct components – maximal activity and temperature optimum (T0) (Kaplan et al. 1991). In all P. occidentalis and P. lucida crosses, CYP2E1 activity segregated in up to three phenotypic groups. In F1 individuals (P. lucida×P. occidentalis V87-15), an overdominant phenotype was generated in 50% of the progeny. The P. lucida phenotype was absent suggesting a maternal effect on the F1 phenotype. Backcrosses of these F1 progeny to P. lucida females resulted in a recovery of the P. lucida phenotype while maintaining expression of an overdominant phenotype in 50% of the progeny. Among F2 progeny, an overdominant phenotype was expressed less often as compared to the F1 generation, and parental phenotypes were observed in equal numbers. Phenotypic expression patterns of CYP2E1 activity among F1 fish changed significantly with replacement of P. occidentalis V87-15 by P. occidentalis AV76-7. The P. lucida and P. occidentalis phenotype was equally distributed among progeny without evidence of an overdominant phenotype. Backcrosses of F1 progeny to P. lucida females resulted in equal amounts of the parental phenotypes. Backcross of an F1 male to a P. occidentalis AV76-7 female increased the P. occidentalis phenotype at the expense of the P. lucida phenotype in resulting progeny. Backcross of a F1 female to a P. lucida male resulted in equal distribution of the parental phenotypes. In addition, a greater number of F2 fish expressed the P. occidentalis phenotype as compared to the P. lucida phenotype. No significant difference in the sex ratios was seen in any of the crosses with the exception of one backcross.