琯溪蜜柚煤烟病的防治方法

该病是由蚧类及蚜虫等害虫的排泄物引起煤烟病菌的大量繁殖而发生。防治该病首先要进行合理修剪,剪除过密枝、枯枝及病虫技等,改善树体通风透光条件,破坏蚧类及蚜虫的滋生环境。然后分别于5－6月和9－10月选用50％辛硫磷1000倍液、20％中西杀灭菊酯3000－5000倍液,或波美0．3－0．5度石硫合剂加0．1％洗衣粉等药剂防治蚧类及蚜虫,间隔10天喷药1次,连喷3次以上。对已出现煤烟病的柚树,应于发病初期选用0．3％－0．5％石灰过量式波尔多液、80％代森锋或50％代森钦op信波等药剂喷施2次,以抑制该病蔓延。琯溪蜜柚煤烟病的防治方法@林慧…     

锐劲特、敌杀死、快杀灵防治草原毛虫田间试验报告

通过对敌杀死、快杀灵、锐劲特3种药剂进行趋低量喷雾防治草原毛虫的药效试验，筛选出最佳药品和使用剂量。结果表明，2．5％敌杀死和25％快杀灵使用剂量分别为225mL/hm^2和300mL／hm2时，即可达到与标准药剂(20％杀灭灵，300mL／hm2)相同的防治效果，因此可作为目前防治草原毛虫的首选药物，适宜在我省大面积防治中推广应用。     

适于草坪斜纹夜蛾防治的绿色农药室内筛选

为了筛选适于草坪害虫斜纹夜蛾（Prodenia litura）防治的绿色农药,采用浸叶法测定比较了5个不同化学类别共20种绿色杀虫剂对斜纹夜蛾3龄幼虫的室内活性。结果表明,7种常用农用拟除虫菊酯类杀虫剂的杀虫效果不及常规有机磷农药毒死蜱,而2种新型拟除虫菊酯四氟醚菊酯和四氟苯菊酯的杀虫效果相当或优于毒死蜱;苯甲酰脲类药剂虱螨脲、氟啶脲和氟铃脲,双酰肼类虫酰肼,杂环类茚虫威和虫螨腈,以及生物源类杀虫剂甲氨基阿维菌素苯甲酸盐7种药剂对斜纹夜蛾的活性高,均符合绿色无公害农药的基本要求,是值得进一步试验开发用于草坪斜纹夜蛾等夜蛾类害虫防治的候选药剂。     

扎兰屯市紫花苜蓿草地螟危害的调查及防治

2003年7月，扎兰屯市草原工作站在成吉思汗镇种植紫花苜蓿150hm^2，8月末～9月初，草地螟第2代幼虫大发生。经调查在8月25日～9月1日期间，虫口密度为18头～24头／m^2，虫情指数高达68．7，紫花苜蓿受害率达85％～90％，严重影响了它的生长发育，直接威胁到它的安全越冬。9月1日～2日，使用4．5％高效氯氰菊酯乳油2000倍液、21％灭杀毙乳油3000倍液喷雾灭虫，防治效果达95％以上，害虫得到了有效控制。     

紫苜蓿褐斑病药剂防治试验

１９８９年～１９９０年选用克灵，甲基布津，多菌灵，百菌清，粉锈灵和灭病威６种药剂，采用随机区组法设计，在人工草地进行了紫苜蓿褐斑病的药剂防治试验。结果表明：以上药剂防病效果显著（防效分别为６８．５９％，６６．２５％，５２．５３％，６７．７６％，６６．１９％，６７．５８％。药剂防治后使其茎叶比下降，脱叶减少，分枝数增加，使苜生物学产量增加１４％～３９％，千粒重增加１４％～１８％，防效较好的药剂是速克     

草地螟的药剂防治试验

草地螟属鳞翅目、螟蛾科,又名黄绿条螟,是草原的主要害虫之一。 多年来,在草原上大面积防治草地螟一般采用化学药剂,化学药剂见效快,但存在着很多缺点,如药物残留,污染环境,危及人畜及害虫天敌安全等,相对化学药剂而言,生物农药克服了这些缺点,但由于生物农药表象慢,所以一直未被推广应用。本试验分别采用生物农药和化学农药对草地螟进行防治,防治率达95％以上,为在草原上科学防治草地螟提供依据。     

73%炔螨特对桑红蜘蛛的防治试验

试验表明73％炔螨特对桑田中的红蜘蛛有较好的防治效果、而且药效时间长,15天以后防效在98％以上,为防治螨类害虫提供了又一种新的推广药剂品种。     

草地螟的药剂防治试验

草地螟属鳞翅目、螟蛾科,又名黄绿条螟,是草原的主要害虫之一。 多年来,在草原上大面积防治草地螟一般采用化学药剂,化学药剂见效快,但存在着很多缺点,如药物残留,污染环境,危及人畜及害虫天敌安全等,相对化学药剂而言,生物农药克服了这些缺点,但由于生物农药表象慢,所以一直未被推广应用。本试验分别采用生物农药和化学农药对草地螟进行防治,防治率达95％以上,为在草原上科学防治草地螟提供依据。     

溴虫腈对几种桑园害虫和家蚕的室内毒力测定及在田间防治的选择性毒力调查

研究杀虫、杀螨剂溴虫腈在桑树害虫与非靶标昆虫家蚕之间以及桑树害虫之间的差异性毒力,为溴虫腈在桑园安全、合理使用提供依据。采用浸叶法测定24%溴虫腈悬浮剂对野桑蚕、家蚕、桑螟、桑尺蠖的室内毒力选择性比值较高,其LC50值倍数比例为362∶126∶1.6∶1,各种试虫对该药剂的敏感程度从大到小依次是桑尺蠖>桑螟>家蚕>野桑蚕,该药剂对家蚕的毒性很小。分别采用80、160、320 mg/L 3种质量浓度溴虫腈悬浮剂稀释液喷施桑树后间隔1、3、6、9 d采摘桑叶饲养家蚕3龄幼虫至上蔟,除用320、160 mg/L溴虫腈悬浮剂稀释液处理区间隔1 d的桑叶养蚕后,家蚕的各项生理指标与清水对照区差异极显著(P<0.01)外,其它处理区无显著差异(P>0.05),并无迟发性毒性效应。田间防治试验表明,24%溴虫腈悬浮剂对桑树害虫的毒力具有选择性,试验期桑园内的几种害虫对该药剂的敏感程度从大到小依次是桑尺蠖>桑螟>桑毛虫>桑剌蛾,320、160、80 mg/L 3种质量浓度溴虫腈悬浮剂稀释液喷施后7 d对桑尺蠖的平均防效极显著优于对照农药267 mg/L辛硫磷稀释液的防效,而对桑螟的平均防效低于对照农药200 mg/L灭多威稀释液的防效(94.2%)。研究结果显示溴虫腈用于桑园害虫防治具有一定的选择性毒力,对非靶标生物家蚕的毒性较低,该药剂适合用于对桑尺蠖等桑园害虫的防治。     

防治茶叶小绿叶蝉药剂试验

近几年,小绿叶蝉成为我县茶树主要害虫之一,每年5～6月有一个为害高峰,导致夏茶失收。过去大多数茶农使用敌敌畏防治小绿叶蝉,现已产生抗药性,防治效果显著下降。为了寻求替代敌敌畏防治小绿叶蝉的药剂,笔者于1991年5月进行了几种药剂试验。现将试验情况小结如下。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein