6种抗凝血杀鼠剂毒饵对布氏田鼠毒效比较

实验室比较了6种抗凝血鼠药毒饵(杀鼠灵、杀鼠醚和敌鼠钠盐供试浓度为0.025%,氯敌鼠钠盐、溴敌隆和溴鼠灵供试浓度为0.005%)对布氏田鼠的毒效。试药配成常规浓度毒饵,对靶鼠进行单个笼养和围栏群养有选择摄食试验,以毒杀率和摄食系数评价毒效。结果表明,单养试验:杀鼠灵和杀鼠醚对试鼠毒杀率分别为60%和80%,摄食系数分别为0.67和0.54;其他试药都达到100%毒杀率,摄食系数分别为0.61、0.71、1.10和0.77。群养试验:杀鼠灵只有50%毒杀率,其他5种试药都达到100%毒杀率;杀鼠灵和杀鼠醚摄食系数较小,分别为0.53和0.75,其他4种试药为0.86～1.11。除了杀鼠灵,其他5种鼠药都适于防治布氏田鼠,但从灭鼠成本和实用性考虑,敌鼠钠盐和氯敌鼠钠盐应为首选。     

Use of captive predators for testing secondary hazards of rodenticides1

The use of captive predators for testing potential secondary hazards of rodenticides is becoming an increasingly important research method. The usefulness of the test results depends on how realistically the test protocol corresponds to natural events and encompasses such factors as the selection of the predator species, sample sizes, methods of dosing the primary species, and the feeding regime of primary consumers to the predators. While such studies can provide excellent data, extreme care must be exercised in the extrapolation of such data to field situations. Some major shortcomings in such extrapolations are: (1) it is difficult under field conditions to know how much toxicant is actually consumed and the amount retained by the rodents; (2) it is even more difficult to determine the frequency and number of primary target animals consumed by predators over time. Test protocol development must of necessity be somewhat subjective, but a strong commitment should prevail to keep the methodology as realistic as possible.     

Laboratory and field trials of the rodenticide brodifacoum against warfarin-resistant Norway rats

Norway rats (Rattus norvegicus) trapped in a low-income housing area in Raleigh, North Carolina, and on a poultry farm in Garner, North Carolina, manifested high levels of resistance to warfarin in laboratory tests. Of the rats tested, 59.1 and 91.7% from the Raleigh and Garner trap sites, respectively, survived a 6-day no-choice test of a diet containing 0.005 % warfarin. The warfarin-resistant rats were subsequently given a choice of a 0.005% brodifacoum bait and a placebo diet. Of 27 rats, 19 died after a 3-day test. Survivors had consumed significantly less brodifacoum (0.1 < P > 0.05) than those that died, but the survivors also died when subjected to an additional 1-day no-choice test of the brodifacoum bait. Field trials, in which warfarin-resistant rats in four poultry houses were fed with poison bait for 14–16 days with 0.005% brodifacoum in a pelletised bait (‘Talon’), resulted in 87–99 % control being achieved.     

The evaluation of anti-coagulants as rodenticides in the laboratory

Samenvatting Het onderzoek van anti-coagulanten als rodenticiden in het biologisch laboratorium van de Plantenziektenkundige Dienst, als onderdeel van de middelenkeuring ten behoeve van de bestrijdingsmiddelenwetgeving, wordt volgens de hierbij beschreven methoden uitgevoerd. Naast de chemische bepaling van het gehalte aan giftig bestanddeel wordt de giftigheid nagegaan in maagsondeproeven na éénmalige toediening (LD 50). Verder wordt de sterftetijd vastgesteld: bij het geregeld dagelijks opnemen van vergiftigd voedsel, tot de dood intreedt; bij dagelijks opnemen gedurende enkele dagen (3, 5 of 7 dagen-proeven) en bij opnemen van vergiftigd voedsel, afgewisseld met opnemen van nietvergiftigd voedsel (onderbrekings-proeven). Ten slotte worden keuzeproeven gedaan om een eventuele afkeer van de dieren voor de middelen te kunnen vaststellen.     

Assessing the impact of rodenticides on the environment1

As with any pesticides, it is recommended that the environmental safety of a rodenticide is assessed in a stepwise manner, i. e. from basic laboratory studies on chemical behaviour and toxicology, through more detailed, specifically designed, studies of the compound's potential environmental hazard, to field experiments if they are shown to be necessary by the results of the lower tier studies. Following the release of the rodenticide onto the market, its environmental safety should be continually monitored through a formalized system for investigating any reports of wildlife death as a result of pesticides.     

杀鼠剂的混配和混用

以增加毒力、提高害鼠的适口性、加强药剂的安全性、调整杀鼠剂作用时间和对毒饵防霉防虫等为目的进行杀鼠剂的混配与混用。混配的类型可归纳为两类 ,一类以杀鼠剂加增效剂或其他非毒杀成分 ,另一类是 2种或多种杀鼠剂的混配与混用。混配的方式包括原药的混配和毒饵的混配     

3种抗凝血类杀鼠剂在喀什农区防治害鼠效果及对家禽的安全性评价

为确定适于防治南疆农区鼠害的抗凝血类杀鼠剂, 在喀什地区疏勒县采用夹捕法、食饵法、粉迹法评估了杀鼠醚、溴敌隆、溴鼠灵的防治效果, 并采用灌胃法给药测试3种杀鼠剂对家鸡Gallus domestiaus和鸽子Columba livia的安全性。结果表明, 连续投放毒饵10 d后, 与溴敌隆防治区相比, 杀鼠醚防治区的阳性粉块和无毒小麦取食量的下降幅度均无显著差异, 但无毒小麦取食量下降的农户比例更高;且防治后褐家鼠比例更低, 防治期间毒饵消耗量更高。连续单独投放溴敌隆30 d的灭鼠效果可达90.9%, 但10 d溴敌隆与20 d溴鼠灵联合防治防效仅为65.9%。灌胃法测试表明, 对当地家禽类的毒性从低到高依次为杀鼠醚、溴敌隆和溴鼠灵。因此, 建议优选毒性较低的杀鼠醚或溴敌隆用于南疆农区鼠害防治。     

A review of secondary-poisoning studies with rodenticides

Rodenticides can become a danger for predators and scavengers if they prey on dead or moribund rodents. One possibility for assessing the hazard potential is to conduct trials in which poisoned rodents are fed to predators. Over the years, numerous such studies have been carried out with a wide range of carnivorous mammals and birds. Since an internationally recognized standard method only recently came into existence, the studies differ in details of trial procedure. The most significant end point is the mortality rate; in addition, blood clotting response often serves as a biomarker. This review includes studies on brodifacoum, bromadiolone, chlorophacinone, coumatetralyl, difenacoum, flocoumafen, warfarin and zinc phosphide which have been published in the open literature or which have been submitted by industry in the authorization procedure for plant protection products.     

Exploring drivers of the usage of anticoagulant rodenticides on UK farms

Anticoagulant rodenticides (ARs) are considered inhumane, show increasingly limited efficacy due to acquired resistance, and carry environmental consequences associated with non-target species uptake. In a questionnaire study of 499 UK farms that all deployed chemical rodenticide we found a high mean reliance (79%), on second generation ARs with just over half of the respondents using no other rodent control methods. Additional methods where deployed, alone or in combination, included predation (41%), kill-trap deployment (16%) and shooting (1%). Nearly 40% of all respondents deployed rodenticides year-round. There was no evidence to suggest that “tidy-farm” measures, such as clearing food spills and minimising on-farm rodent harbourage sites aimed at minimising rodent-associated problems, were associated with a lower likelihood of year-round deployment; in fact trends in our analyses suggested the opposite. We therefore encourage operators to fully evaluate the true necessity of rodenticide deployment before AR use.     

Competitiveness against grass weeds in field pea genotypes

Summary Field pea is an important pulse crop in southern Australia, but its competitiveness against weeds is low. Two experiments were conducted in consecutive years to examine the ability of different genotypes to compete against grass weeds. Field pea was grown in the presence or absence of Lolium rigidum or wheat. In each experiment significant genotypic differences in field pea competitiveness occurred and some genotypes had consistently high or low levels of competitiveness in both years. Tall genotypes generally suppressed L. rigidum and wheat more effectively than short genotypes. Leaf type (conventional, semileafless or tare-leaf) only affected competitiveness before flowering and had no effect on yield loss from weed competition. Maturity had little effect on competitive ability. A genotype × environment analysis for competitive ability showed that there was considerable variation in the response to the level of competition (environment) as well as in mean competitiveness among field pea genotypes. Using wheat as a weed identified genotypic differences in field peas more effectively and more consistently than using L. rigidum . Visual assessment of wheat growth with field pea was strongly correlated with a specific genotype's competitiveness, which may form the basis of a simple field-based screening method for competitive ability.     

The toxicity of three second-generation rodenticides to Barn Owls

The toxicity of three second-generation rodenticides to Barn Owls (Tyto alba Scop.) has been investigated. Brodifacoum, difenacoum and flocoumafen were separately fed to owls over a period of 15 days via rodenticide-fed mice to simulate the potential route of exposure in the wild. The owls survived a cumulative dose of each rodenticide of at least 1.9 mg kg^?1 owl body weight over 15 days. This is equivalent to the consumption of two 25 g mice with a rodenticide residue of 1 mg kg^?1 each day for 15 days. Residue analysis confirmed that the liver is the organ which retains the largest residue of ingested rodenticide.     

Non-invasive method for monitoring the exposure of Barn owls to second-generation rodenticides

Chemical analysis of rodenticide residues in regurgitated owl pellets has been shown to be a sensitive, non-invasive method for monitoring the potential exposure of Barn Owls to second-generation rodenticides in their prey. The method, originally developed for flocoumafen, has been extended to two other rodenticides. brodifacoum and difenacoum. The method was validated as part of a toxicity study in which Barn Owls were separately fed 40–130 μg day ^?1 of brodifacoum, difenacoum and flocoumafen in mice over 15 days. Each day an average of 25% of the consumed rodenticide was regurgitated in the pellets.     

Warfarin-based rodenticides: Mode of action and mechanism of resistance

Warfarin and related substances have been in use as rodenticides for fifty years. They act by binding to the enzyme vitamin K 2,3-epoxide reductase, thereby interrupting the cellular recycling of vitamin K. Vitamin K in its hydroquinone form is an essential cofactor for the synthesis of functional prothrombin and related blood-clotting factors. The binding with the reductase is essentially irreversible, indicating these compounds have a prolonged half-life in target tissues; 7–10 days for warfarin and congeners and over 100 days for the second generation rodenticides or ‘superwarfarins’ such as difenacoum, brodi-facoum, and flocoumafen. Rat liver contains 1–2 nmole of enzyme per gram tissue which is a 4–5 fold overcapacity for maintaining effective vitamin K recycling. The use of warfarin as a rat poison has resulted in the natural selection of warfarin-resistant rats. The resistance is inheritable. Two distinct warfarin resistance genotypes, Welsh and Scottish, have been identified, clearly differing in their biochemistry of vitamin K epoxide reductase. In the Welsh strain, resistance arises from an altered enzyme expressing reduced reactivity to warfarin, whereas the reductase from the Scottish strain is as sensitive as the normal enzyme, but the interaction with warfarin is now readily reversible. The altered enzyme leaves the Welsh rat in need of higher dietary vitamin K intake. The superwarfarins cope with the resistance by having their structures firmly bind with the altered enzymes. Reduced sensitivity to warfarin-based rodenticides may also be pharmacokin-etically based, arising from increased warfarin biotransformation. This mechanism may be responsible for resistance to some of the superwarfarins such as difenacoum. A third resistance mechanism may arise from an enhanced capacity to synthesize vitamin K from menadione, a commonly used additive in animal foods on farms. The choice of rodenticide in the case of warfarin resistance should be guided by the underlying mechanism of resistance.     

荔枝麻点病田间防治药剂筛选及评价

荔枝麻点病是我国大陆地区荔枝上普遍发生的一种新病害,其病原为暹罗刺盘孢Colletotrichum siamense.为筛选防治该病的有效药剂并评价其农药残留安全性,于2012年-2018年分别在8个不同的果园开展了田间药剂防治试验,并于2016年和2018年分别对果实的农药残留量进行了检测.试验结果表明,250 g/...     

Resistance testing and the effectiveness of difenacoum against Norway rats (Rattus norvegicus) in a tyrosine139cysteine focus of anticoagulant resistance,Westphalia, Germany

BACKGROUND: Anticoagulant resistance in Norway rats at foci in Belgium, Denmark, France, Germany, the Netherlands and the United Kingdom is genetically characterised by the same single nucleotide polymorphism (SNP) and consequent amino acid exchange from tyrosine to cysteine at location 139 of the vkorc1 gene (i.e. tyrosine139cysteine or Y139C). The purpose of this study was to assess the degree of resistance among rats at two infested farm sites in the Y139C focus in Westphalia, Germany, using blood clotting response (BCR) tests, and to determine the practical efficacy of applications of a commercial 50 ppm difenacoum bait (Neokil^?) against them. RESULTS: BCR tests showed that the difenacoum resistance factor (RF) among the Y139C rats was about 2.5. DNA analysis for the Y139C mutation revealed that it was present among rats at the two sites with a prevalence of 75 and 93%. Applications of difenacoum bait at the two sites achieved 86.8 and 59.9% control. The different outcomes did not appear to be due to differences either in the degree and prevalence of resistance or in the quantities of poisoned bait consumed. CONCLUSION: The study showed that, although the RF for difenacoum among rats carrying the Y139C SNP was apparently low, an acceptable level of control of resistant Norway rat infestations was not achieved using difenacoum. Continued use of anticoagulants against rats that are resistant to them will exacerbate resistance problems in terms of both increased severity and prevalence. These conclusions are likely to apply elsewhere in Europe where the Y139C SNP occurs. Copyright © 2012 Society of Chemical Industry     

麦田布顿大麦草的化学防除药剂筛选

布顿大麦草为麦田入侵杂草, 为尽早建立对该杂草的化学防除技术, 本研究采用室内盆栽法测定了布顿大麦草对21种除草剂的敏感性?结果表明:土壤处理剂41%氟噻草胺悬浮剂对布顿大麦草具有良好的防除效果, 42%氟啶草酮悬浮剂?60%丁草胺乳油?40%砜吡草唑悬浮剂?960 g/L精异丙甲草胺乳油对布顿大麦草的防除效果一般, 50%扑草净可湿性粉剂?50%异丙隆可湿性粉剂?45%二甲戊灵微囊悬浮剂?50%吡氟酰草胺可湿性粉剂防除效果不理想; 茎叶处理剂7.5%啶磺草胺水分散粒剂?12.5%烯禾啶乳油?41%草甘膦异丙胺盐水剂对布顿大麦草防除效果好, 5%咪唑乙烟酸水剂?8%炔草酯水乳剂?30 g/L甲基二磺隆可分散油悬浮剂?8%烟嘧磺隆可分散油悬浮剂?7%双唑草腈颗粒剂?70%氟唑磺隆水分散粒剂对布顿大麦草的防除效果一般, 5%唑啉草酯乳油?7.5%双环磺草酮颗粒剂?69 g/L精噁唑禾草灵水乳剂防除效果不理想?氟噻草胺?在推荐剂量492 g/hm2下, 处理21 d后对布顿大麦草的鲜重抑制率为75.40%; 啶磺草胺?草甘膦异丙胺盐?烯禾啶在推荐剂量14?1 500?187.5 g/hm2下, 处理21 d后对布顿大麦草的鲜重抑制率分别为73.96%?60.60%?65.07%?综合本研究结果及除草剂使用特性, 麦田布顿大麦草可采用氟噻草胺土壤封闭或者啶磺草胺茎叶喷雾处理进行有效防除; 油菜田布顿大麦草可采用烯禾啶进行防除; 非耕地布顿大麦草可采用草甘膦异丙胺盐进行防除?     

Efficacy of lufenuron as chemosterilant against Ceratitis capitata in field trials

Two field trials in citrus orchards in Turis (Valencia, Spain) and Denia (Alicante, Spain) were performed in order to test the sterilant effect of the insect growth regulator lufenuron against wild medfly Ceratitis capitata (Wiedemann) populations. Two application methods for lufenuron were tested: spraying, in spots, an emulsion of lufenuron in a protein bait, and hanging delta traps that contained a proteinaceous gel with lufenuron (solid bait). The sterilant effect was measured as medfly population reduction, reduction of fruit damage in treated fields, and the number of eggs hatching in punctured fruits. In order to assess the efficacy of lufenuron treatments, we recorded results obtained from two different zones in both trial fields: an outer zone, close to untreated fields, and an inner zone, in the centre of lufenuron treated fields. We observed a minimum sterilant effect in the outer zone and a maximum sterilant effect in the inner one. The maximum sterilant effect was in the inner zone, where a reduction of medfly population of 80.4% in the sprayed field and a reduction of 77.6% in the solid bait field was observed. In addition, the greater the distance from the untreated zones of the treated orchard (inwards), the lower the fruit damage and medfly population level. In this inner zone, fruit punctured by medfly developed significantly fewer larvae (38.8%) than punctured fruits from the outer zone (68.6%). In addition, we recorded the decline in the activity of the lufenuron treatments with time. Lufenuron activity persisted in field for at least 2 weeks with spray applications, and for 3 months with bait gels.