嗜虫书虱种群增长模型的研究

【目的】构建嗜虫书虱Liposcelis entomophila (Enderlein)在不同环境条件下的种群增长模型,为粮库书虱种群预测预报提供基础数据和理论模型。【方法】通过构建嗜虫书虱实验种群生命表,分析温度、湿度、食物破碎率和种群初始密度对嗜虫书虱种群数量动态的影响,验证种群的指数增长模型,并拟合温湿度与内禀增长率的函数关系。【结果】在温度26-34℃,湿度65%-85%,食物破碎率4%-12%的条件下,温度和湿度对发育历期有显著影响,三者对种群数量趋势指数、净增殖率、内禀增长率的影响均不显著。三者对种群增长影响的主次顺序为:温度>湿度和食物破碎率。嗜虫书虱种群增长的最适条件为温度34℃、相对湿度85%、食物破碎率12%。当种群初始密度为0.26-1.04头/cm2时,嗜虫书虱种群数量呈指数增长。【结论】在22-34℃,相对湿度65%-85%的环境中,嗜虫书虱种群数量动态与温度和湿度的关系可以拟合为Nt=N0EXP[(0.002 96T+0.021 67RH-0.037 2)t]。     

嗜卷书虱的实验生态研究

在8种温度(17.5～35℃)及5种相对湿度(50%、60%、70%、80%和90%)条件下,以全麦粉、酵母粉、脱脂奶粉(10∶1∶1)为食料,系统研究了嗜卷书虱Liposcelis bostrychophila Badonnel实验种群生态学特性。获得了该虫在不同温、湿度条件下生长发育、生存和繁殖的一系列特性和参数,包括各虫态发育历期、存活率、发育起点温度、有效积温和平均繁殖力等,并建立了发育速率、存活率及繁殖力的理论模型。     

杀虫剂胁迫下嗜卷书虱和嗜虫书虱能源物质的代谢比较

采用比色法测定嗜卷书虱（Liposcelis bostrychophila）和嗜虫书虱（L．entomophila）体内甘油三酯、多糖和可溶性蛋白的贮存量。结果表明,嗜虫书虱体内3种物质的贮存量均显著高于嗜卷书虱。在毒死蜱和丁硫克百威的胁迫下,嗜虫书虱体内3种物质的变化幅度均大于嗜卷书虱,其中甘油三酯的含量先增高后降低,整体呈现下口抛物线趋势;多糖和可溶性蛋白的消耗率增加。这些说明在毒死蜱和丁硫克百威的作用下,书虱更多地启动了多糖和可溶性蛋白的代谢,降低了对甘油三酯的利用,以应对杀虫剂的胁迫。     

四种杀虫剂对两种书虱羧酸酯酶和乙酰胆碱酯酶的抑制作用

选用有机磷类杀虫剂(敌敌畏、毒死蜱、对氧磷)和氨基甲酸酯类杀虫剂(丁硫克百威),通过生物测定(药膜法)和生化测定(比色法)比较了嗜卷书虱和嗜虫书虱对所选药剂的敏感差异性。根据LC50可知嗜虫书虱对所选药剂比嗜卷书虱敏感。离体酶活性分析结果显示嗜卷书虱和嗜虫书虱的羧酸酯酶只对敌敌畏敏感,且嗜卷书虱比嗜虫书虱更敏感;4种药剂对乙酰胆碱酯酶均有强烈的抑制作用,同样是嗜卷书虱比嗜虫书虱敏感。乙酰胆碱酯酶的动力学研究结果和离体酶活性测定相一致。聚丙烯酰胺凝胶电泳分析显示,4种杀虫剂离体条件下对2种书虱的酯酶同工酶的抑制能力有明显差异,其中敌敌畏的抑制力最强;但对不同同功酶的抑制趋势(对大分子的抑制似乎较强)是一致的。酶的敏感性分析结果与生测结果比较表明,2种书虱的耐药力差异与其乙酰胆碱酯酶和酯酶对药剂的敏感性无关。如要弄清耐药力机制,需做进一步研究。     

两种书虱微卫星富集文库的构建及比较

利用链霉亲和素与生物素之间的强亲和性原理,将链霉亲和素偶联的磁珠与微卫星探针(AC)12、(TC)12、(ATC)8、(ATG)8、(AAC)8、(ATAC)6及(GATA)6退火结合后,再亲和捕捉含接头和微卫星序列的单链书虱基因组DNA限制性酶切目的片段,经PCR扩增形成双链后进行克隆、建库。结果表明本研究成功构建了嗜卷书虱和嗜虫书虱共13个微卫星富集文库,包括6个嗜卷书虱文库,7个嗜虫书虱文库,其平均阳性克隆率为71.17%。经检测发现共得到两种书虱260个微卫星位点。这两种书虱微卫星富集文库的建立和高多态性微卫星位点的筛选将为嗜卷书虱和嗜虫书虱的种群遗传与进化、基因连锁图谱构建、分子系统发育研究等提供大量分子遗传标记,对其在实仓中的持续控制提供遗传学信息。     

中国常见仓储书虱PCR-RFLP快速识别

应用PCR-RFLP技术,对我国4种常见仓储书虱即嗜虫书虱Liposcelis entomophila(Enderlein)、嗜卷书虱L.bostrychophila(Badonnel)、无色书虱L.decolor(Pearman)和小眼书虱L.paeta(Pearman)开展快速识别方法的研究。采用CTAB法从上述4种书虱体内提取基因组DNA,选用1对引物扩增16S rDNA基因区域,分别用5种限制性内切酶对PCR产物进行酶切。结果表明,PCR扩增片段大小约为500bp,用限制性内切酶DraI酶切得到的片段可将供试书虱区分开。该方法不受4种供试书虱地理种群、虫态(成虫、若虫)和性别的影响,可用于4种书虱的快速识别。     

储藏根茎类中药材孳生书虱种类研究

本研究从安徽淮南采集储藏根茎类中药材样本共30种,采用直接镜检法和光照驱虫法分离其中孳生的书虱,光镜下鉴定书虱种类并计数。结果表明,30份样本中书虱的孳生率为933%（28/30）,检获的书虱为嗜卷书虱（Liposcelis bostrychophila Motschulsky,1852）;该书虱年平均孳生密度为57头/克,孳生指数为142。本研究表明安徽淮南部分储藏根茎类中药材有书虱孳生,在中药材储藏和加工过程中应注意书虱的防制。     

嗜卷书虱气调抗性形成过程中能源物质的积累与利用

报道了嗜卷书虱对高二氧化碳,低氧气调抗性形成过程中能源物质的积累以及抗性形成后在气调胁迫下能源物质的利用情况。结果表明随着抗性水平的提高。嗜卷书虱体内甘油三酯,多糖以及游离氨基酸含量均显升高。在气调胁迫环境下,嗜卷书虱抗性品系能源物质的消耗率明显低于敏感品系,甘油三酯的积累以及在气调摁迫下缓慢消耗可能是其抗气调性的主要内在机理之一。     

温度对沙巴拟刀角瓢虫生长发育和繁殖的影响

【目的】明确不同温度对沙巴拟刀角瓢虫Serangiellasababensis生长发育和繁殖的影响,为烟粉虱天敌的应用提供理论依据。【方法】在17、20、25、30和32℃的恒温条件下,测定沙巴拟刀角瓢虫的存活率和发育历期,计算出发育起点温度、有效积温和生命表参数。【结果】成虫前期存活率和产卵量在25℃时最高,分别为80.78%±6.42%和（284.00±59.71）粒。从卵发育至成虫的发育历期在17℃时最长（57.06±1.28）d,30℃时最短（13.85±0.12）d。成虫前期的发育起点温度和有效积温分别为（11.29±1.86）℃和（271.40±34.44）日·度。在25℃时,沙巴拟刀角瓢虫种群的净增殖力R0最高,内禀增长率rm在30℃最高。【结论】沙巴拟刀角瓢虫的最适温区为25-30℃,与烟粉虱Bemisia tabaci (Gennadius)的最适温区相近,可以在烟粉虱暴发的时期大量应用。     

无色书虱AChE基因克隆及其系统进化分析

利用RT-PCR结合RACE技术克隆获得了无色书虱Ld acel的3'端序列和Ld ace2的全长序列(GenBank登录号分别为:FJ647186和FJ647187).其中Ld ace2基因全长2111 bp,ORF 1917 bp,编码638个氨基酸组成的前体蛋白,成熟蛋白的分子量为71.9 kDa,理论等电点为4.70,序列比对表明该基因包括AChE家族的所有保守性功能位点;Ld acel基因仅获得了3'端1616 bp的序列,编码500个氨基酸残基,序列比对发现,除缺少形成一对二硫键的半胱氨酸外,Ld acel包含了AChE家族的所有保守性功能位点.结合其它物种AChE构建的分子进化树可以看出,AChE分为4个类群:昆虫I型AChE类群、脊椎动物AChE类群、昆虫Ⅱ型AChE类群和线虫AChE类群,其中无色书虱Ld acel和Ld ace2分别属于昆虫Ⅰ型AChE类群和昆虫Ⅱ型AChE类群,且与嗜卷书虱和嗜虫书虱的AChE具有最近的进化关系.     

Effect of temperature and humidity on development, survival and oviposition in laboratory populations of Eriworm, Philosamia ricini (Boisduval) (Lepidoptera Saturniidae)

Experiments were conducted on laboratory populations of Eriworm, Philosamia ricini Boisduval to study the effect of temperature and humidity on development, growth, survival and oviposition. Experiments were performed at four different temperatures (22 +/- 2 degrees C, 26 +/- 2 degrees C, 28 +/- 2 degrees C and 34 +/- 1 degrees C) each with three different humidities (50%, 70% and 90% relative humidity). Shortest developmental period (42 days) was observed in 28 +/- 2 degrees C and 70% RH. Longest developmental period was (63.6 days) observed in 22 +/- 2 degrees C at 50% RH. Highest larval weight (9.1 g) was found in 28 +/- 2 degrees C at 70% RH. Best pupal weight was observed in 26 +/- 2 degrees C at 70% RH. Weight of silk material was found to be maximum in 26 +/- 2 degrees C at 70% RH. Survival was best in 28 +/- 2 degrees C and 26 +/- 2 degrees C at 70% RH. Oviposition was found to be highest in 28 +/- 2 degrees C at 70% RH.     

Influence of temperature on the hygropreference of the Collembolan, Cryptopygus antarcticus, and the mite, Alaskozetes antarcticus from the maritime Antarctic

The hygropreference of adult Cryptopygus antarcticus and Alaskozetes antarcticus was investigated over 2 h at 5, 10 and 20 degrees C, along humidity gradients (9-98% RH) established by means of different salt solutions. Two chamber arrangements were employed, linear and grid, to determine any influence of thigmotactic behaviour on distribution within the RH gradient. The humidity preference of both species varied with temperature. At 5 and 10 degrees C, C. antarcticus distributed homogeneously showing no clear RH preference. At 20 degrees C, this species preferred the highest humidity (98% RH). A. antarcticus demonstrated a preference for the lowest humidity (9% RH) at 5 degrees C, but at 10 degrees C its distribution differed between the two arena types. At 20 degrees C, A. antarcticus showed no clear humidity preference. Assays to control for experimental asymmetries along the gradient; thigmotactic behaviour; and aggregative behaviour exclude these factors as explanations for the observed results. The mean initial water content of samples did not differ significantly between temperature regimes (C. antarcticus: 68.6, 71.1 and 74.3%; A. antarcticus: 68.1, 70.1 and 68.6% at 5, 10 and 20 degrees C respectively), but the level of water loss increased significantly with temperature. The influence of desiccation tolerance and the ecological significance of the observed humidity preferences are discussed.     

温湿度对安徽虫瘟霉在桃蚜居群中流行的影响

用安徽虫瘟霉(Zoopphthoraanhuiensis)接种桃蚜(Myzuspersicae)无翅成蚜3头和健蚜3头组成新的蚜群若干,在不同温湿组合条件下任其繁殖、发病和传染,以评价温湿度对该菌在蚜群中流行的影响.持续26d观察,在偏低温与各湿度(90～100%RH)的组合中均成功诱发了蚜病流行,其程度受湿度影响较小.在10℃与各湿度组合中,最终感病死亡率为72.9%～98.2%,15℃下为78.7%～94.4%,流行强度极大.而20℃下仅100%RH诱发了高强度流行病,其余湿度下感病死亡率仅为5.1%～12.8%.在25℃,100%RH下死亡率仅27.2%.与所有湿度组合中的对照蚜群相比,10℃下流行病控蚜效果为89.5%～96.9%,15℃下为96.1%～98.2%,20℃下为45.9%～85.7%,25℃下为56.4%～69.7%.逐步回归分析表明,安徽虫瘟霉引发的蚜病流行与温度及其相对湿度和蚜群带菌后天数的互作项密切相关(r2=0.82,a＜0.01),这些变量在很大程度上决定了安徽虫瘟霉是否在蚜群中流行.     

飞虱虫疠霉继发性感染对桃蚜数量增长的控制作用

用飞虱虫疠霉（Pandora delphaics)“孢子浴”接种的桃蚜(Myzus persicae)无翅成蚜在离体甘蓝菜叶片（65cm^2)上建立蚜群,在不同温度（10－30℃）和湿度（74％－100％RH）的组合条件下任其繁衍,发病和交互感染,以评价该菌的控蚜效果。在25个温,湿度组合处理（8次重复,每重复含3头接种成蚜)中,蚜群均不同程度的发病死亡,在历时30d的观察中,以高温（20－30℃）,高湿（95％RH）组合条件下的蚜群发病快且死亡率高,蚜尸上产生的孢子有效地引起若蚜继发性感染。与相同温度下不带菌的对照蚜群相比,次于30℃下,各湿度除个别例外,第8d的控蚜率达30％以上,第20d达80％以上。在10℃和15℃下,控蚜效果一般不如上述较高温度下,且与湿度的关联程度相对较低,但最大控蚜效果均发生在100％RH处理中。结果表明,飞虱虫疠霉用于蚜虫防治的潜力很大,值得深入研究和开发利用。     

Influence of environmental storage relative humidity on biological indicator resistance, viability, and moisture content.

The effect of environmental storage relative humidity (RH) on the moisture content, viability, and moist heat and gaseous ethylene oxide (EO) resistance of biological indicators (BIs) was evaluated. No statistically significant difference was observed between the initial Bacillus stearothermophilus spore population and the spore population of BIs stored at 20 degrees C and 0, 20, 44, of 55% RH or under ambient, 4 degrees C, or -20 degrees C conditions after 12 months. A statistically significant decrease in moist heat resistance from initial starting levels was found for BIs stored at 20 degrees C and either 0 or 20% RH. There was a statistically significant decrease in the B. subtilis BI spore population, compared with initial levels, when the BIs were stored at 20 degrees C and 0% RH concomitant with a significant increase in their EO resistance. BI storage at 20 degrees C and 20 or 44% RH, or under ambient, 4 degrees C, or -20 degrees C conditions, had no significant effect on EO resistance. BIs stored at 20 degrees C and 66% RH demonstrated a significantly lower EO resistance compared with starting levels.     

温湿度对稻纵卷叶螟卵的联合作用

为了探讨温湿度在稻纵卷叶螟Cnaphalocrocis medinalis （Guenée）种群发展中的作用, 通过室内实验调查了不同温度和湿度组合下该蛾卵的发育历期、 胚胎发育情况、 孵化率和卵粒重量的变化。结果表明： 在相同温度下卵历期随相对湿度的增大而缩短, 孵化率随相对湿度的加大而提高。在22℃下低于46%的相对湿度显著降低了卵的孵化率, 而在25～34℃下低于66%的相对湿度会引起孵化率的显著降低, 37℃下卵无论在何种湿度中均不能孵化。在50%左右的低湿条件下, 温度高于28℃后卵也不能孵化。温度在22～31℃和相对湿度在77%～100%范围内, 卵的孵化率无显著差异, 这属于稻纵卷叶螟卵的适宜温湿度范围。稻纵卷叶螟卵的发育起点温度和有效积温分别为10.1±0.6℃和63.7±3.5日度。卵的孵化率（Y）与温湿系数（RH/T）间呈显著的逻辑斯蒂曲线关系Y=0.8662/[1+exp(17.4084-7.5714×RH/T)]。温湿系数在2.34以下时卵孵化率将低于50%, 而达到3.0左右时孵化率接近最高值。结论认为, 低湿造成的稻纵卷叶螟卵重量显著降低、 卵粒干瘪、 胚胎发育受阻是致死卵的主要原因。     

Development rates of two Xenopsylla flea species in relation to air temperature and humidity

The rate of development of immature fleas, Xenopsylla conformis Wagner and Xenopsylla ramesis Rothschild (Siphonaptera: Xenopsyllidae) was studied in the laboratory at 25 degrees C and 28 degrees C with 40, 55, 75 and 92% relative humidity (RH). These fleas are separately associated with the host jird Meriones crassus Sundevall in different microhabitats of the Ramon erosion cirque, Negev Highlands, Israel. This study of basic climatic factors in relation to flea bionomics provides the basis for ecological investigations to interpret reasons for paratopic local distributions of these two species of congeneric fleas on the same host. Both air temperature and RH were positively correlated with duration of egg and larval stages in both species. Change of humidity between egg and larval environments did not affect duration of larval development at any temperature. At each temperature and RH, the eggs and larvae of X. ramesis did not differ between males and females in the duration of their development, whereas female eggs and larvae of X. conformis usually developed significantly faster than those of males. For both species, male pupae developed slower than female pupae at the same air temperature and RH. Air temperature, but not RH, affected the duration of pupal development. At each humidity, duration of the pupal stage was significantly longer at 25 degrees C than at 28 degrees C: 15.3+/-1.7 vs. 11.7+/-1.2 days in X. conformis; 14.1+/-2.0 vs. 11.5+/-1.7 days in X. ramesis, with a significantly shorter pupal period of the latter species at 25 degrees C. These limited interspecific bionomic contrasts in relation to basic climatic factors appear insufficient to explain the differential habitat distributions of X. conformis and X. ramesis.     

Life table study of Sitotroga cerealella (Lepidoptera: Gelichiidae), a strain from West Africa

Life table studies for the Angoumois grain moth, Sitotroga cerealella (Olivier), a pest on stored maize, Zea mays L., in West Africa, were conducted as part of the expansion of a mathematical simulation model that has been developed for two pests of stored maize. The effects of four temperatures (20, 25, 30, and 35 degrees C) and two relative humidity levels (44 and 80%) on developmental time, age-specific survivorship and fecundity, sex ratio, and intrinsic rate of natural increase (r(m)) of S. cerealella were investigated. Sex ratio was close to 1:1 at all temperatures and humidity. Minimum development time occurred close to 32 degrees C and 80% RH for both males and females, and developmental time of females was significantly shorter than that of males. Immature survivorship was highest between 25 and 30 degrees C and 80% RH and lowest at 35 degrees C under both humidity conditions. A similar low level was found at 20 degrees C and 44% RH. The greatest fecundity (124 eggs per female) occurred at 20 degrees C, 80% RH. The maximum r(m) value was 0.086 d(-1) at 30 degrees C and 80% RH, but the growth rate declined dramatically at 35 degrees C. If compared with the few other life table studies conducted on this species on maize in India and North America, some variation among the strains becomes evident. A common conclusion for the current study and previous ones is that optimal population development for S. cerealella occurs at approximately 30 degrees C and at high humidity.     

Influence of temperature, photoperiod and humidity on oviposition and egg hatch of the root-feeding flea beetle Longitarsus bethae (Chrysomelidae: Alticinae), a natural enemy of the weed Lantana camara (Verbenaceae)

The root-feeding flea beetle Longitarsus bethae Savini & Escalona, was introduced into South Africa as a candidate biological control agent for the noxious and invasive weed, Lantana camara L. As part of the study to predict the beetles' survival in its new range, the influence of climatic conditions on its egg development and reproductive performance were investigated in the laboratory. The threshold temperature (T degrees) and degree-days (DD) required for egg hatch were determined after exposing the eggs to various constant temperatures (12, 17, 22, 27 and 32 degrees C) in separate growth chambers. The DD required for egg hatch was 178.6, and the temperature threshold required for egg hatch was 11.3 degrees C. Survival of eggs varied from 27 to 56% at 32 and 17 degrees C, respectively, and was optimum between 17 and 25 degrees C. Oviposition was examined under high and low relative humidity (RH) regimes while egg hatch was determined at six RH levels, each maintained in a separate controlled growth chamber set at a constant temperature (25 degrees C). Whilst RH had no influence on oviposition, eggs were highly susceptible to aridity, and continuous exposure to relative humidity below 63% for more than three days was wholly lethal at 25 degrees C. Optimum egg hatch occurred at RH between 85 and 95% for up to 12 days. The effect of day length on oviposition and subsequent egg hatch was investigated under two photoperiod regimes. Neither oviposition nor subsequent egg hatch was influenced by photoperiod. The knowledge obtained will be useful for mass rearing as well as field release programmes for L. bethae.     

Effect of temperature and relative humidity on spinning behaviour of silkworm (Bombyx mori.L)

The rate of spinning of silkworm larva (Bombyx mori.L) was slow at 22 degrees C and fast at 38 degrees C. The time taken for completion of cocoon was longest at 98 +/- 2% and least at 40 +/- 2% RH. However, good quality cocoons were spun at 22 degrees C and 65 +/- 5% RH, hence it would be advantageous to maintain this temperature and relative humidity at the time of cocoon spinning in the case of CB race of silkworm.