嗜卷书虱抗气性和抗药性品系呼吸代谢的比较

系境地比较了嗜卷书虱的抗高二氧化碳(RHCO2)、抗低氧高二氧化碳(RHCLO)、抗敌敌畏(RDDVP)和抗磷化氢(RPH2)4个抗性品系及敏感品系不同虫态的个体在鲜重及其呼吸代谢等方面的差异。结果表明抗性品系的体重和呼吸代谢发生了显著变化。抗气性品系(RHCO2和RHCLO)各虫态的鲜重均比抗药性品系(RDDVP和RPH2）增加。RHCO2品系和RDDVP品系(除卵期外)每个发育阶段的耗氧量均比敏感品系显著增加;从全生育期来看,RH—CLO品系的耗氧量最低,而RDDVP品系最大。RHCLO品系单位时间呼出CO2量明显多于其他品系。成虫的代谢速率RDDVP品系是敏感品系的1．92倍,而其余几个抗性品系的代谢速率均比敏感品系低,RHCLO品系的代谢速率最低,仅为敏感品系的44．41％。     

嗜卷书虱抗性与敏感品系乙酰胆碱酯酶的比较

对嗜卷书虱(LiposcelisbostrychophilaBadonnel)DDVP抗性品系(RDDVP)和PH3 抗性品系(RPH3 )乙酰胆碱酯酶(AChE)的生物化学性质进行了初步研究。比较发现嗜卷书虱RDDVP品系和RPH3 品系的酶原蛋白均显著高于敏感品系(P< 0. 05), 2个抗性品系间也存在着显著差异(P< 0. 05)。RDDVP和RPH3 品系的AChE活力和比活力都明显低于敏感品系,且差异均达到了显著水平(P< 0. 05 )。RDDVP品系的Km 值较敏感品系显著升高(P< 0.05),是敏感品系的1. 33倍,说明酶发生了质的变化,与底物的亲和能力显著降低;而RPH3 品系无显著变化。从Vmax看,RDDVP无明显变化,而RPH3 却显著降低(P< 0. 05)。研究结果表明, 2个抗药性品系都存在靶标抗性,其抗性的形成与AChE在量和(或)质上的变化有一定的相关性。     

中国虱属分类研究 Ⅳ.常见的几种仓储虱

本文是“中国虱属分类研究”系列论文的第 4篇 ,主要针对 4种世界常见虱属Liposcelis昆虫进行了重新描述 ,即嗜卷虱L .bostrychophilaBadonnel、嗜虫虱L .ento mophila(Enderlein)、无色虱L .decolor(Pearman)和皮氏虱L .pearmaniLienhard。旨在为我国口岸植物检疫 ,特别是有关虱属昆虫的鉴定工作提供参考。     

嗜卷书虱和嗜虫书虱抗性及防治方法的研究概况

书虱在我国粮库中的发生越来越严重,对粮食安全造成了很大的威胁。其中嗜卷书虱和嗜虫书虱已经发展成为"双低"(低氧、低药剂)和"三低"(低氧、低药剂、低温)储粮中的害虫优势种群。对储粮保护剂、气调、熏蒸技术、植物精油、昆虫生长调节剂等对该两种书虱的防治进行了综述,同时介绍了两种书虱的抗性现状,旨在为实仓中该两种书虱的防治提供一定的依据。     

温度、湿度对嗜虫书虱生长发育和繁殖的影响

嗜虫书虱以全麦粉及酵母粉作饲料时,其各期发育速率与温度呈逻辑斯蒂曲线关系,世代发育起点和有效积温分别为15.16℃,306.75日度。在20—35℃范围内,世代存活率、种群内禀增长率以及成虫产卵量较高,高低温区均呈下降趋势。理论上29.55℃时周限增长率(λ)最大,达1.0628倍/天。高湿有利于其生长发育和繁殖,湿度低于60％时,各虫态均不能发育存活。结果表明,嗜虫书虱生长发育、繁殖最适温区为28—30℃,最适相对湿度在80％左右。     

平房仓散储小麦降温期间嗜虫书虱的种群密度变化

对平房仓散装小麦堆秋冬降温期间采用取样手工筛检和探管式诱捕器诱集的方法,定点检测观察了嗜虫书虱Liposcelis entomophila的种群密度变化。结果表明,嗜虫书虱在小麦堆的种群变化因粮温的降低而减少。在粮温15℃以上时,可以检测到较多的书虱成(若)虫,当粮温降到5~2℃左右时,检测到的书虱密度几乎为0。在粮温25~1℃的散储小麦堆中,采用探管式诱捕器诱集每7 d检测一次的方法与取样手工筛检方法得到的检测结果基本一致。     

Potential of piperonyl butoxide‐synergised pyrethrins against psocids (Psocoptera: Liposcelididae) for stored‐grain protection

BACKGROUND: Piperonyl butoxide (PB)‐synergised natural pyrethrins (pyrethrin:PB ratio 1:4) were evaluated both as a grain protectant and a disinfestant against four Liposcelidid psocids: Liposcelis bostrychophila Badonnel, L. entomophila (Enderlein), L. decolor (Pearman) and L. paeta Pearman. These are key storage pests in Australia that are difficult to control with the registered grain protectants and are increasingly being reported as pests of stored products in other countries. Firstly, mortality and reproduction of adults were determined in wheat freshly treated at 0.0, 0.75, 1.5, 3 and 6 mg kg^?1 of pyrethrins + PB (1:4) at 30 ± 1 °C and 70 ± 2% RH. Next, wheat treated at 0.0, 1.5, 3 and 6 mg kg^?1 of pyrethrins + PB (1:4) was stored at 30 ± 1 °C and 70 ± 2% RH and mortality and reproduction of psocids were assessed after 0, 1.5, 3 and 4.5 months of storage. Finally, the potential of synergised pyrethrins as a disinfestant was assessed by establishing time to endpoint mortality for adult psocids exposed to wheat treated at 3 and 6 mg kg^?1 of synergised pyrethrins after 0, 3, 6, 9 and 12 h of exposure. RESULTS: Synergised pyrethrins at 6 mg kg^?1 provided 3 months of protection against all four Liposcelis spp., and at this rate complete adult mortality of these psocids can be achieved within 6 h of exposure. CONCLUSION: Piperonyl butoxide‐synergised pyrethrins have excellent potential both as a grain protectant and as a disinfestant against Liposcelidid psocids. Copyright © State of Queensland, Department of Employment, Economic Development and Innovation, 2010. Published by John Wiley and Sons, Ltd.     

Influence of concentration, temperature and humidity on the toxicity of phosphine to the strongly phosphine-resistant psocid Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae)

BACKGROUND: The psocid Liposcelis bostrychophila Badonnel, is a widespread, significant pest of stored commodities, has developed strong resistance to phosphine, the major grain disinfestant. The aim was to develop effective fumigation protocols to control this resistant pest. RESULTS: Time to population extinction of all life stages (TPE) in days was evaluated at a series of phosphine concentrations and temperatures at two relative humidities. Regression analysis showed that temperature, concentration and relative humidity all contributed significantly to describing TPE (P<0.001, R(2)=0.95), with temperature being the dominant variable, accounting for 74.4% of the variation. Irrespective of phosphine concentration, TPE was longer at lower temperatures and high humidity (70% RH) and shorter at higher temperatures and low humidity (55% RH). At any concentration of phosphine, a combination of higher temperature and lower humidity provides the shortest fumigation period to control resistant L. bostrychophila. For example, 19 and 11 days of fumigation are required at 15 degrees C and 70% RH at 0.1 and 1.0 mg L(-1) of phosphine respectively, whereas only 4 and 2 days are required at 35 degrees C and 55% RH for the same respective concentrations. CONCLUSIONS: The developed fumigation protocols will provide industry with flexibility in application of phosphine.     

Comparison of acetylcholinesterase from three field populations of Liposcelis paeta Pearman (Psocoptera: Liposcelididae): Implications of insecticide resistance

The toxicological and biochemical characteristics of acetylcholinesterases (AChE) in Liposcelis paeta Pearman were investigated in three field populations collected from Nanyang city of Henan Province (NY), Wuzhou (WZ) and Hezhou (HZ) Cities of Guangxi Province, China. The result of bioassay showed that the LC_50s of the NY (281.4802 mg/m²) and the WZ (285.0655 mg/m²) to dichlorvos were 1.156-fold and 1.171-fold higher than that of the HZ (243.5197 mg/m²), respectively. Compared to NY population, the activity per insect and the specific activity of AChE in WZ and HZ populations were significantly higher, and significant kinetic differences among the three populations were also observed. The apparent Michaelis–Menten constant (K_m) for acetylthiocholine iodide (ATChI) was obviously lower in NY than that in WZ and HZ populations, indicating a higher affinity to the substrate ATChI in the NY population. The affinity to the substrate ATChI between WZ and HZ population was also significantly different. As for V_max, the values of WZ and HZ populations were significantly greater when compared to that for NY population, suggesting a possible over expression of AChE in the former two populations. The inhibition studies of AChE indicated that paraoxon-ethyl, demeton-S-methyl, carbaryl, and eserine all possessed some inhibitory effects on AChE in L. paeta. The results of I_50S suggested that when compared to the other two populations, while AChE from HZ population was less sensitive to paraoxon-ethyl and demeton-S-methyl. The contradiction with the result of the bioassay might be due to the different insecticides used in the bioassay. Although both carbaryl and eserine had excellent inhibitory effects, there was no significant difference among the three populations. The statistical analysis of the bimolecular rate constants (k_i) was consistent with the above situation that carbamates expressed remarkable inhibitory effects. It was noticeable that NY population was most sensitive to carbaryl while least to eserine. The differences in AChE among three populations may attribute to the difference in control practices for psocids between Henan and Guangxi Provinces.     

甲酸乙酯对嗜卷书虱成虫的熏蒸致死作用研究

采用广口瓶密闭熏蒸法,在实验室条件下研究甲酸乙酯（EtF）在不同条件下对储物害虫嗜卷书虱Liposcelis bostrychophila成虫的致死作用。结果表明,处理时间和温度显著影响甲酸乙酯对嗜卷书虱成虫的熏蒸致死效果。甲酸乙酯在24h内就能发挥很好的熏蒸活性,在16℃左右的温度下比在31℃的温度下的熏蒸效果好。甲酸乙酯在12,24,36,48,60h条件下的LC50分别为15．882,15．676,14．011,13．154,10．495。在20,25,30％条件下,熏蒸处理嗜卷书虱成虫24h,其LC50分别为11．372,13．283,15．676μl／L;处理48h时则分别为10．857,12．891,13．1154μL/L。