实验室条件下黑龙江几种主要农业害鼠昼夜活动节律的研究

采用自动记录装置测试了黑龙江地区6种主要农业害鼠的昼夜活动节律和活动强度。结果表明,达乌尔黄鼠为昼行性鼠种,中午时段出现明显的活动间歇期以避开强烈的日晒;莫氏田鼠为昼夜活动型鼠种,日夜活动强度差异不显著,与其生活于草滩底部营食草根的生活方式相适应。大仓鼠、小家鼠、褐家鼠和黑线姬鼠都为夜行性鼠种,其中以小家鼠和黑线姬鼠最为典型,而大仓鼠和褐家鼠在日间都具有相当强度的活动,褐家鼠则是供试鼠种中唯一在各个时段都有活动的夜行鼠种。6种供试鼠种的主要活动特征与前人研究的结果基本相符,但其活动节律与其他研究结果存在活动高峰时间、活动强度等差异,表现出这些鼠种与黑龙江地区特定气候条件的适应。     

长尾仓鼠对溴敌隆的抗药性研究

采用8d无选择摄毒法检测山西省隰县长尾仓鼠对第2代抗凝血类灭鼠剂溴敌隆的抗药性.结果表明,溴敌隆对长尾仓鼠毒杀率为89.5 %,死亡鼠平均食毒剂量为2.99 mg/kg,平均致死时间为9.24 d,存活鼠平均食毒剂量为3.50 mg/kg,抗性发生率为10.5%.研究认为,长尾仓鼠对溴敌隆已经形成了抗药性个体,但并未产生抗药性种群.     

洞庭湖区东方田鼠对溴敌隆的敏感性

从洞庭湖防洪大堤护坡和湖滩捕捉试鼠,在实验室做无选择性摄食试验。将试鼠雌雄分开,随机分组,配制0.000 2％溴敌隆毒饵进行不同时间的攻毒试验。用SPSS进行几率单位加权回归法(Bliss法)的计算,探讨不同食毒期与对应死亡率之间的关系。结果表明,东方田鼠性别之间对溴敌隆的敏感性差异无统计学意义,故将雌雄数据合并计算,得毒力回归方程y=0.07+2.65x,LFP50、LFP98、LFP99及其95％置信限分别是0.94(0.43～1.33)、5.63(3.51～20.83) d和7.14(4.15～33.52) d。按WHO修订以致死99％敏感靶标鼠种的食毒期(LFP99)取整天数作为抗药性检验标准,洞庭湖区东方田鼠对0.000 2％的溴敌隆毒饵食毒期超过8 d存活为产生抗药性。     

山西隰县长尾仓鼠的发生及溴敌隆对长尾仓鼠的毒力

为了确定溴敌隆毒杀长尾仓鼠的适宜浓度,为今后选择控制长尾仓鼠的药物提供科学依据,于2006年7~12月,运用4 d4次经口灌药的方法,在山西隰县测定了溴敌隆对长尾仓鼠的毒力。结果表明:溴敌隆对长尾仓鼠的口服致死中量(LD50)为1.315 0 mg/kg,回归方程式为y=6.166 2x+4.265 9。按灭鼠药等级标准,溴敌隆对长尾仓鼠属剧毒,因此,在长尾仓鼠分布占优势的地区,可推广使用溴敌隆。     

几种增效剂的增效作用机理研究

以敏感和抗性棉铃虫为试虫,比较测定了ＤＥＦ、ＰＢＯ、ＳＶ１和Ｓ２对氰戊菊酯的增效作用。结果表明,四种增效剂对抗菊酯类药剂的ＫＱＲ棉铃虫具有明显或显著的增效作用,而对于相对敏感的ＨＤＳ棉铃虫,它们的增效作用均比对抗性棉铃虫的弱,甚至没有增效作用。增效作用强度与棉铃虫抗性水平及主导抗性机制有关。生化分析表明,ＰＢＯ和ＳＶ１是通过直接抑制多功能氧化酶系（ＭＦＯ）的某种单加氧酶（如甲氧试卤灵－Ｏ－脱甲基酶     

三种增效剂对棉铃虫增效作用

用３个不同地区的棉铃虫田间种群分别测定了３种增效剂对３种杀虫剂的增效作用。结果表明ＰＢ对氯氟氰菊酯,ＤＥＦ对辛硫磷,ＰＢ和ＴＰＰ对灭多威增效较好,而且棉铃虫的抗性水平越高,增效剂的增效作用越突出。     

几种荧光增白剂对SfaMNPV的增效作用

利用化学增效因子提高杆状病毒的毒力,是扩大其实用性的重要途径.笔者以棉铃虫Helicoverpa armigera 3龄幼虫为供试虫,测试了几种荧光增白剂对芹菜夜蛾核型多角体病毒Syngrapha falcifera multiple nuclear polyhedrosis virus,SfaMNPV 包含体(OB)、多角体来源病毒粒子(PDV)毒力的增效作用.     

三种增效剂对甜菜夜蛾防治的增效作用

甜菜夜蛾 Spodoptera exigua( Hübner)近年来在我国很多地区爆发成灾 ,发生区域南至广东、台湾、福建 ,北到东北地区 ,而且其与棉铃虫 ( H elicoverpa armigera Hübner)一样 ,都是杂食性害虫 ,寄主植物十分广泛。甜菜夜蛾爆发的原因很多 [1 ] ,其中对常规化学农药的高抗性是重要原因之一 [2 ]。利用增效剂增强农药对抗性害虫的防治效果是害虫抗性治理的主要措施之一 ,如增效醚 ( PBO)、MGK2 6 4被推荐与拟除虫菊酯类杀虫剂混合使用防治对有机磷、拟除虫菊酯类农药有抗性的田间小菜蛾 [3] 。本试验利用采自田间的甜菜夜蛾种群 ,测定了 …     

嗜线虫致病杆菌与七种杀虫剂混配对小菜蛾毒杀增效作用评价

采用浸叶法测定了嗜线虫致病杆菌Xenorhabdus nematophila HB310(Xn HB310)与7种常用杀虫剂混配后对小菜蛾3龄幼虫的毒杀增效作用,并对具有增效作用的混配组合进行了最佳配比的筛选和增效作用的评价。结果显示,Xn HB310仅与氯氰菊酯混配表现出明显的增效作用,协同毒力指数(cf)为30.9;当Xn HB310与氯氰菊酯质量比在1006.4∶2.6～816∶4之间时,混配药剂均表现为增效作用;当两种药剂的质量比为952∶3时,增效作用最强,此时的共毒系数最高为335。Xn HB310与乐斯本、吡虫啉或甲氨基阿维菌素苯甲酸盐(甲维盐)混配均表现为相加作用,cf值分别为9.6、-6.9和-18.6,Xn HB310与菜喜、灭幼脲或阿维菌素混配则表现出明显的拮抗作用,cf值分别为-48.4、-24.9和-57.1。     

助剂对烟嘧磺隆的增效作用

在温室条件下研究了13种助剂对烟嘧磺隆防除稗草和狗尾草的增效作用。结果表明,无机盐助剂中的硫酸铵和硝酸铵、表面活性剂中的有机硅Silwet408、油类助剂中的油酸异丁酯有较好的增效作用。     

新疆南部农区鼠害调查与成因分析

南疆农区鼠害严重,但基础资料不足。为摸清当地鼠害发生特点,提供有效治理依据,本研究于2018年-2019年在南疆5地州39乡64村开展实地与问卷调查,并采用夹捕法调查害鼠种群构成。结果表明,南疆5地州农村普遍遭受鼠害影响,喀什与和田地区农田受害比例达89.4%,问卷结果表明农户和农田鼠害发生率均大于75%,且西部地区重于东部,约一半受访农户估计每年因鼠害损失超过500元。褐家鼠Rattus norvegicus是农户主要害鼠,占比超过70%;农田则以小家鼠Mus musculus和乌拉尔姬鼠Apodemus uralensis为主。这些结果表明,南疆农区鼠害处于重发态势,褐家鼠是主要鼠害来源,并有外来入侵风险。下一步应聚焦于监测主要害鼠种群动态规律,阐明褐家鼠来源和侵入机制,并探索建立适于当地的害鼠防治模式。     

Differential expression of cytochrome P450 genes between bromadiolone-resistant and anticoagulant-susceptible Norway rats: a possible role for pharmacokinetics in bromadiolone resistance

BACKGROUND: Anticoagulant resistance in Norway rats, Rattus norvegicus (Berk.), has been suggested to be conferred by mutations in the VKORC1 gene, encoding the target protein of anticoagulant rodenticides. Other factors, e.g. pharmacokinetics, may also contribute to resistance, however. To examine the involvement of pharmacokinetics in bromadiolone resistance in male and female rats, liver expression profiles of seven cytochrome P450 genes from a Danish bromadiolone-resistant rat strain (with an Y139C-VKORC1 mutation) were compared with profiles from an anticoagulant-susceptible strain. RESULTS: In the presence of bromadiolone, the Cyp2e1, Cyp2c13, Cyp3a2 and Cyp3a3 genes were significantly overexpressed, while Cyp2c12 expression was suppressed in resistant female rats compared with susceptible females. Relative to susceptible males, resistant males showed significant overexpression of the Cyp2a1, Cyp2e1, Cyp3a2 and Cyp3a3 genes. On exposure to bromadiolone, females had higher Cyp2e1 expression than males, which possibly explains why female rats are generally more tolerant to anticoagulants than male rats. CONCLUSION: Results suggest that bromadiolone resistance in a Danish strain of Norway rats involves enhanced anticoagulant metabolism catalysed by cytochrome P450-2e1, -3a2 and -3a3. This pharmacokinetically based bromadiolone resistance is to some extent sex differentiated, as female resistance furthermore seems to involve overexpression of cytochrome P450-2c13 and suppression of P450-2c12, whereas male resistance appears to involve P450-2a1 overexpression.     

A review of biochemical mechanisms of warfarin resistance in the house mouse

The biochemical mechanisms of warfarin resistance in the house mouse (Mus musculus L.) have not been fully investigated. In some populations of warfarin-resistant mice there is a reduction in sensitivity of hepatic vitamin K-epoxide reductase to inhibition by warfarin. This is similar to a proposed mechanism of anticoagulant resistance in the Norway rat (Rattus norvegicus Berk.). The same enzyme in other warfarin-resistant populations is, however, sensitive to warfarin inhibition. Other studies have indicated that detoxification may play a role in conferring warfarin resistance in house mice.     

Field evaluation of capsaicin as a rodent aversion agent for poultry feed

Developing additional techniques for reducing animal feed contamination by rodents and controlling rodent populations is critical to efforts aimed at reducing the occurrence of Salmonella spp infection on poultry farms. Capsaicin, a compound found in chili peppers of the genus Capsicum, produces a burning sensation in the mouth of mammals and is used effectively as an animal deterrent for some pest species. Applied to poultry feed, capsaicin may be effective as an aversive agent to deter rodent feeding and enhance acceptability of rodenticide baits. We tested capsaicin-treated poultry diets (2000 and 3000 Scoville Heat Units, SHU) in no-choice feeding trials at four active New York farms in the winter of 1997-1998. At all farms, consumption of the 2000 SHU diet by rodents (Norway rats, Rattus norvegicus (Berk), and house mice, Mus musculus L) was significantly less than consumption of a control diet. Consumption of the 3000 SHU diet by rodents was significantly less than consumption of a control diet at three of the four farms. Overall, consumption of treated diets was 58-97% and 55-98% less than consumption of the control diet, for the 2000 and 3000 SHU diets, respectively. These reductions appeared to be related closely to the availability of alternative feed sources at these farms. Two-choice feeding trials involving a rodenticide bait (0.05 g kg(-1) brodifacoum) and the 3000 SHU diet demonstrated that Norway rats preferred the rodenticide to the capsaicin-treated poultry feed. Overall, rodenticide bait acceptance was high (95.6%) when offered simultaneously with capsaicin-treated poultry feed. Although poultry managers must utilize several techniques to manage rodent pests, the use of capsaicin-treated diets to reduce feed losses and increase rodenticide bait acceptance appears promising. Use of capsaicin-treated feed on poultry farms may substantially reduce feed contamination by rodents and ultimately the incidence of Salmonella infection in poultry.     

Resistance tests and field trials with bromadiolone for the control of Norway rats (Rattus norvegicus) on farms in Westphalia, Germany

BACKGROUND: The aim of this study was to determine the incidence and the level of resistance to bromadiolone among rats on farms suspected of being foci of resistance by using the international normalised ratio (INR)‐based blood clotting response (BCR) test. Whether the level of reduced susceptibility constitutes ‘practical resistance’ was subsequently determined in field trials. RESULTS: The 2.5 multiple of the ED₅₀ baseline was used to test for the incidence of resistance, and higher multiples in the range of the suspected resistance factor were used to investigate the degree of resistance. The ED₅₀ values of bromadiolone in resistant rats were confirmed in the range 4.70–7.05 mg kg^?1 for males and 4.62–6.61 mg kg^?1 for females. Variations within these ranges appeared between farms. According to the BCR resistance tests, 50–100% of rats were classified as resistant prior to the field trials; 29–100% of rats survived the treatments. CONCLUSION: BCR tests based on the use of the INR and baselines are suitable for determining the incidence and for assessing the level of resistance in populations of Norway rats. The majority of rats of the Westphalian resistant strain, characterised by the Y139C marker in VKOR, are resistant to bromadiolone under practical control conditions. Copyright © 2011 Society of Chemical Industry     

Reproductive success of bromadiolone-resistant rats in absence of anticoagulant pressure

Resistance to anticoagulant rodenticides in brown rats (Rattus norvegicus Berk.) is associated with pleiotropic effects, notably with an increased dietary vitamin K requirement. Owing to this disadvantage, resistance is believed to be selected against if anticoagulant selection is absent. In small experimental populations of wild brown rats, an investigation was carried out to establish whether tolerance to anticoagulant exposure changed over a period of 2 years. In the same populations, DNA microsatellite markers were used to infer parentage, and this made it possible to estimate reproductive success of sensitive and resistant rats and estimate effective population size, Ne. Even though there was evidence for a selection against resistant rats with high vitamin K requirement, anticoagulant tolerance was not seen to be significantly influenced in the absence of bromadiolone selection. As the population size under investigation was small, random genetic drift may have played a role in this. In the presence of bromadiolone selection, however, the tolerance was significantly increased, suggesting that continuous selection will increase the proportion of highly resistant rats in the population. It was found that, for both males and females, surprisingly few individuals contributed to the next generation with numerous offspring, and most breeders contributed with none or a single offspring. The expected higher reproductive success and consequent increase in proportional numbers of sensitive rats in the absence of anticoagulant selection could not be observed. Among the resistant rats, moderately resistant females were found to be better breeders than highly resistant breeders, but for resistant males the reverse was true. This could be explained by the fact that the increased vitamin K requirement results in sex differential selection; in highly resistant males the selection presumably takes place at the immature stage, whereas in females the vitamin K requirement becomes crucial at the reproductive stage, as vitamin K is not only essential for the blood clotting process but also for bone formation.     

新疆干旱半干旱农田应用0.2%莪术醇饵剂防治害鼠的效果

为了解0.2%莪术醇饵剂在新疆干旱半干旱农田应用的可行性,2022年4月至7月, 在新疆博州温泉县进行了该药防治害鼠试验。施药在3个试验点(即3个重复)进行, 在害鼠繁殖高峰期前施药, 投放药饵后30、60 d和90 d调查防控效果。结果显示:3个试验区域的结果趋势相似, 校正灭效基本维持在50%以上。与空白对照区相比, 优势鼠种灰仓鼠与根田鼠试验投饵区的雌鼠怀孕率明显下降, 小家鼠、灰仓鼠平均胎仔数明显降低, 小家鼠、灰仓鼠和根田鼠施药区域的鼠类个体的亚成体比例与对照区域明显下降, 说明该药剂对当地害鼠的繁殖具有明显的控制作用, 可达到控制害鼠数量的目的, 适口性也较好, 可以在当地推广应用。