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1.
This is the third survey of control practices for ectoparasites on sheep farms in Northern Ireland, providing data comparative to those recorded in previous surveys in 1981 and 1988. Data relating to all aspects of ectoparasite control were collected from 210 farms representing 4% of the total sheep population. Quantitative data have been adjusted to provide accurate estimates of total pesticide usage. Since the previous survey in 1988, the number of sheep farms in Northern Ireland has increased by 10% to 11 692 with a consequent 39% increase in sheep population to 2.9 million. Despite this level of expansion, the total quantity of organophosphorus compounds used for ectoparasite control has remained approximately constant at 7–8 tonnes. The report considers that compulsory sheep‐dipping, prescribed since 1970 and revoked in 1993, impacted significantly on subsequent ectoparasite control practices and consequent pesticide usage. During 1997, approximately 20% of sheep farmers relied on alternative methods to control ectoparasites, including injectable formulations of avermectins and pour‐on formulations of insect growth regulators and pyrethroids. Dipping formulations containing pyrethroid compounds, which accounted for <1% of treatments in 1988, increased to 9% in 1997. Previously, regulatory sheep‐dipping periods were specified during the autumn months, which tended to increase dipping frequency. The majority of farmers dipping sheep during the summer strictly for blowfly maggot (Diptera: Calliphoridae) control were required to perform additional compulsory sheep‐dipping during the autumn. Withdrawal of compulsory sheep‐dipping has allowed farmers to synchronise dipping practices to control the major ectoparasites of sheep at a single dipping occasion. An estimated 7.5 × 106 litres of surplus dipwash required disposal and there were approximately equal numbers of farmers disposing dipwash immediately after sheep‐dipping or on occasions up to and including subsequent dipping. The decline in the number of farmers who allowed dipwash to run‐off into soakaways or surrounding soil observed in 1988 continued in 1997. The majority of farmers used tractor‐operated pumps to dispose of dipwash into slurry tanks for subsequent disposal onto permanent pasture. © Crown copyright 2000. Reproduced with the permission of Her Majesty's Stationery Office. Published for SCI by John Wiley & Sons, Ltd.  相似文献   

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A survey of sheep dipping in Scotland in 1978 showed that about 42 tonnes of organophosphorus and 17 tonnes of organochlorine insecticides were used to control ectoparasites. Information is presented about their pattern of use and about the disposal of surplus sheep dip and the empty containers. Six river pollution incidents involving sheep dips in 1978 are recorded. The main geographical areas affected by headfly (Hydrotaea irritans Fall.) and the measures taken against them are noted.  相似文献   

4.
The usage of pesticides on crops grown mostly for processing is reviewed. Topics presented include: the relative costs of production, the extent of usage of pesticides and the reasons for their use, regional differences and changes in usage, the methods of application, the frequency of application and the growers' assessment of the success of the treatments. Examples of problems in attaining the desirable degree of control are given.  相似文献   

5.
A survey of sheep dipping and spraying in Scotland during 1973 has shown that about 40 tonnes of organophosphorus, 8 tonnes of organochlorine and 2 tonnes of carbamate insecticides were used to control ectoparasites. Substances used to combat headfly (Hydrotaea irritans) and the main areas of Scotland affected by this pest are noted. Information about the pattern of dipping in relation to geographical area, season and flock size and about the disposal of surplus dip and empty containers is presented. Though a small potential for environmental damage still exists no evidence of such came to light.  相似文献   

6.
Animals taken in Tasmania including duck (Anas superciliosa), eel (Anguilla australis), English perch (Perca fluviatilis), white-faced heron (Ardea pacifica), brown trout (Salmo trutta), European starling (Strunus vulgaris), cat (Felis cattus), cormorant (Phalacrocorax sp.), mutton bird (Puffinus tenuirostris), Tasmanian devil (Sarcophilus harrisii), rainbow trout (Salmo gairdnerii), Tasmanian raven (Corvus mellori), tench (Tinca tinca), and quail (Coturnix sp.) were sampled for p,p'-DDE, pp,p'-TDE, p,p'-DDT, lindane, dieldrin, and hexachlorobenzene. Pesticide residue levels exceeded 0.1 ppm in at least one animal from each area and in the majority of animals sampled from all areas. Pesticide sources could not be determined, partly because migratory species such as ducks, mutton birds, cormorants, and eels may have ingested pesticides outside of Tasmania.  相似文献   

7.
奸狡长蠹属(Apate)主要分布在非洲,其中部分种类传入世界其他地方;如咖啡黑长蠹(点刻奸狡长蠹A.monachus)传入小亚细亚、中南美,成为世界性害虫。该虫为我国的潜在危险性害虫,我国尚无该属的分布记录,曾有口岸截获毛额奸狡长蠹(A.femoralis)的记录;最近张家港检验检疫局在来自刚果的原木中截获了钻孔奸狡长蠹(A.terebrans)雌虫,有关口岸应对来自疫区,特别是非洲的原木加强检疫,以防该属害虫传入我国。该属近似种之间的区别,尚无中文描述,有些种存在一定的地理差异,给鉴定带来困难。笔者根据Lesne的法文原著翻译介绍如下,仅供参考。  相似文献   

8.
A. Lebeda 《Phytoparasitica》1992,20(3):203-210
Under controlled inoculation, a set of 56 accessions belonging to 19 wild species of the genusCucumis was studied for resistance to seven isolates of cucurbit downy mildew (Pseudoperonospora cubensis (Berk. et Curt.) Rostow.) from cucumber. No resistance toP. cubensis was detected in theseCucumis accessions. In three host accession/pathogen isolate combinations, limited sporulation was observed. Nine newCucumis species are described as hosts forP. cubensis: C. africanus, C. ficifolius, C. figarei, C. meeusii, C. metuliferus, C. myriocarpus, C. leptodermis, C. sagittatus andC. zeyheri. Results are discussed in relation to the origin and evolution ofCucumis species.  相似文献   

9.
The aim of the present survey was to isolate entomopathogenic rhabditids in an arid region. The survey was conducted in the Negev desert, located in the southern part of Israel. Soil samples were collected from 21 sites and the presence of entomopathogenic nematodes in the soil samples was determined by usingGalleria mellonella larvae as bait. Entomopathogenic nematodes, identified as heterorhabditids, were isolated only from soil samples obtained from under the canopy of irrigated fruit trees, planted in sandy soils. The nematodes from the new isolated populations were subjected to low relative humidity (75%) for 3 days after preconditioning for 72 h at 97% RH. Under these conditions, fewer than 10% survived for 48 h.  相似文献   

10.
The activity of the (+)-trans-chrysanthemic acid ester of (±)-allethrolone (Bio-allethrin) is shown to be superior to that of the (±)-cis, trans-isomers (allethrin), against houseflies, two species of grain beetle and larvae of the yellow fever mosquito. The efficiency of the (+)-trans-isomer compares favourably with that of pyrethrins when each is used alone or with piperonyl butoxide.  相似文献   

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The present experiments to be reported were declared the effect of mixtures from the three antioxidant vitamins (A, C and E) on some hematologic parameters, liver and testes nucleic acid system, blood immune-system, chromosomal aberration and sperm-shape of tefluthrin (LD50) intoxicated rats. A total of 90 male albino rats were used divided into six groups (15 rats each).Oral ingestion of technical tefluthrin significantly decreased the count of RBCs, Hb content and stimulated plasma LDH activity, also reduced the levels of blood immuno globulins (IgG, IgA and IgM). Under the effects of tefluthrin liver and tests nucleic acids (RNA and DNA) contents were decreased and the activities of nucleases (RNAase and DNAase) were also inhibited relative to these values of normal healthy control group.Chromosomal aberrations and sperm-shape abnormalities were significantly increased after ingestion of tefluthrin, compared to the control group. Mitotic index (MI) and sperm count was decreased significantly due to the potential cytotoxicity of tefluthrin.Treatment of intoxicated rats with antioxidant vitamins (A, C and E) mixtures reduced the harmful influences of tefluthrin. Blood IgG, IgA and IgM levels, RBCs count and Hb content were improved relative to normal healthy animal group.The frequency of chromosome aberrations in bone marrow cells of intoxicated rats treated with vitamins as well as the frequency of sperm abnormalities were decreased and readjusted near to that of the healthy control animals, also MI and sperm counts were increased significantly near to the control group after vitamins ingestion as treatments.It is interesting to note that, the ingestion of vitamins mixtures readjusted and normalized the hematologic parameters around those of normal healthy control. In case of liver and nucleic acids system, the disturbed effects of the pesticide induction of RNA and DNA contents as well as RNAase and DNAase activities were alleviated by the treatments with the present antioxidative vitamins mixtures, in which the nucleic acids contents and nucleases activities of liver and testes of tefluthrin intoxicated rats were ameliorated and normalized compared with those of normal control.  相似文献   

13.
Virulence and efficacy of five species and strains of the entomopathogenic nematodes of the families Steinernematidae and Heterorhabditidae:Steinernema riobravis, Steinernema feltiae strains Ger. and UK, andHeterorhabditis bacteriophora strains HP88 and IS5, against the prepupal and pupal stages of the western flower thrips (WFT),Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), were investigated in the laboratory. Although all these nematodes controlled WFT to some extent, they differed in efficiency. The heterorhabditid nematodeH. bacteriophora strain HP88 was more specific to the soil-inhabiting WFT stages (36–49% thrips mortality). The steinernematid nematodesS. riobravis andS. feltiae strains Ger. and UK had only a slight effect (10% mortality) on prepupal and pupal populations of WFT, andH. bacteriophora strain IS5 had the least effect of all. A possible reason for such species variation is suggested and discussed.  相似文献   

14.
Indoor resting mosquitoes were collected in 7 localities (250 houses) of Phnom Penh at various periods. The mosquitoes were collected for 8 min in every house by means of an aspirator and net. A total of 16 species of mosquitoes resting in houses were found, one of them for the first time in Kampuchea. Culex quinquefasciatus was the predominant species in 6 of the localities observed; its predominance in houses was more or less evident; Aedes aegypti prevailed in one locality. The percentage of A. aegypti predominance in houses corresponds with the risk of occurrence of dengue haemorrhagic fever. Anopheles vagus was found resting in higher abundance in houses of one locality. This fact is of little epidemiological significance because of the zoophilic character of An. vagus in Kampuchea. On the other hand even uncommon occurrence of Anopheles subpictus found in houses may signalize a possibility of an endemic occurrence of malaria in Phnom Penh.  相似文献   

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Being one of the most abundant and species‐rich groups of natural enemies occurring in all agroecosystems, spiders are variably affected by pesticide applications. Here, a review is given of research on spider ecotoxicology. More than 40 species of spiders and almost 130 pesticides (acaricides, insecticides, fungicides and herbicides) have been tested so far in the field or under laboratory conditions. Field studies show that the degree of population reduction following pesticide application is a function of a number of factors inherent to pesticides, crops and spider species (guilds). These studies also revealed indirect effects via habitat and prey disruption. Among laboratory studies, a number of papers have investigated only the direct lethal effect. A meta‐analysis of these data reveals that spiders are mainly affected by acaricides and insecticides, particularly neurotoxic substances. Currently, ecotoxicological research on spiders is focused more on direct sublethal effects on a variety of behavioural traits (locomotion, predation, web‐building, reproduction, development) and physiology. Yet a standardised approach to the evaluation of sublethal effects is lacking. A few studies have provided some evidence for hormesis in spiders. Future research should be more concentrated on sublethal effects and the estimation of long‐term changes in spider populations as a result of pesticide treatment. Copyright © 2012 Society of Chemical Industry  相似文献   

17.
BACKGROUND: Tropical plants are recognised sources of bioactive compounds that can be used for pest control. The objective of this study was to evaluate the biological activity of compounds present in Acmella oleracea (Asteracea) against Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), which is the main pest of tomato crops in Latin America. The selectivity of these compounds to the predator Solenopsis saevissima (Smith) (Hymenoptera: Formicidae) and to the pollinator Tetragonisca angustula (Latr.) (Hymenoptera: Apidae: Meliponinae) was also of interest. RESULTS: A bioassay screening with hexane and ethanol extracts from 23 plants was performed. The hexane extract of A. oleraceae was the most active of the extracts and was selected for further study. The following three alkamides were isolated from a hexane extract of the aerial parts of A. oleracea : spilanthol, (E)‐N‐isobutylundeca‐2‐en‐8,10‐diynamide and (R, E)‐N‐(2‐methylbutyl)undeca‐2‐en‐8,10‐diynamide. All of the isolated compounds showed insecticidal activity, with spilanthol being the most active (LD50 = 0.13 µg mg?1) against T. absoluta . The alkamides were selective to both beneficial species studied. CONCLUSION: The crude hexane extract of A. oleraceae showed high insecticidal activity and can be used to control T. absoluta in organic or conventional crops. Quantification of LD50 values of isolated compounds against T. absoluta showed that alkamides could serve as potent insecticides for T. absoluta control programmes. Spilanthol was the main alkamide active isolated. This alkamide is the most promising as it has the highest insecticidal activity and is selective to non‐target organisms. Copyright © 2011 Society of Chemical Industry  相似文献   

18.
为研究植保无人机低空低容量喷雾技术在实现茶园农药减量中的作用,通过在茶园喷施20%吡虫啉可湿性粉剂,比较其与传统大容量喷雾技术对茶小绿叶蝉Empoasca flavescens的防治效果。结果表明,使用3种植保无人机喷雾,安装有TEEJET110015#喷头的植保无人机的雾滴沉积密度为24.1~127.4个/cm~2,平均值为75.8个/cm~2,沉积量为0.002~1.15μg/cm~2,均值0.58μg/cm~2;安装有TEEJET11001#喷头的植保无人机的雾滴沉积密度为15.0~80.4个/cm~2,平均值为47.7个/cm~2,沉积量均值为0.01~1.38μg/cm~2,均值0.70μg/cm~2;安装有TEEJET11003#喷头的植保无人机的雾滴沉积密度为9.2~18.2个/cm~2,平均值为13.7个/cm~2;沉积量为0~1.14μg/cm~2,均值0.57μg/cm~2。农药利用率为49.3%~58.2%。使用3种传统器械喷雾,担架式动力喷雾机喷雾得到的沉积量为0.02~0.30μg/cm~2,均值0.16μg/cm~2,背负式手动喷雾器喷雾得到的沉积量为0.01~0.46μg/cm~2,均值0.23μg/cm~2,背负式电动喷雾器喷雾得到的沉积量为0.01~0.65μg/cm~2,均值0.33μg/cm~2。农药利用率为33.7%~39.6%。结果表明,3种植保无人机喷雾的农药沉积量和利用率均高于3种传统的施药器械,但其喷雾的均匀性还有待提高。施药后4 d,植保无人机低空低容量喷雾对茶小绿叶蝉防治效果为85.8%~90.4%,传统大容量喷雾对茶小绿叶蝉防治效果为91.8%~93.2%,两者差异不显著。药后10 d,前者对茶小绿叶蝉防治效果为72.9%~75.6%,后者防治效果为65.8%~71.6%,说明植保无人机低空低容量喷雾对茶小绿叶蝉的防治效果优于传统大容量喷雾。研究结果表明,植保无人机低空低容量喷雾有着更长的持效期,为茶园的农药减施增效提供了可能性。  相似文献   

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除危害各种储藏物 ,虱属昆虫也可随活体植物、木材、木质包装、废纸、土壤等进行远距离传播。为便于口岸检疫人员及时、准确鉴定所截获的虱属昆虫 ,本文记述了该属 2种中国新记录 ,即鲍氏虱liposcelisbouilloniBadonnel和地虱L .edaphicaLienhard ,并对其进行了再描述  相似文献   

20.
The gastric absorption of [1-naphthyl-1-14C]N-methylcarbamate (radiolabeled carbaryl) administered intragastrically (7.5 μmoles/kg body wt) to fasted, anesthetized female rats was investigated by measurement of 14C absorption and by identification of the radiolabeled constituents in the portal blood. At 22 and 67 min after dosing, 52.6 ± 14.1% (n = 3) and 81.7 ± 15.7% (n = 3), respectively, of the 14C was absorbed from the stomachs (ligated pylori) of rats with intact portal circulation. In another experiment, 69.1 ± 25.9% (n = 3) of the 14C was absorbed from the rat stomachs (ligated pylorus and esophagus) during 66.0 ± 1.0 min of total portal blood collection (via an in vivo perfusion technique). The radiolabeled material in the collected portal blood accounted for 97.2 ± 1.9% (n = 3) of the 14C absorbed from rat stomachs. On the basis of thin-layer chromatography, gas chromatography, and infrared spectroscopy, 89.3% of the radiolabeled material in the collected portal blood was [1-naphthyl-1-14C]N-methylcarbamate.  相似文献   

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