桑树新害螨——柑桔始叶螨害桑及生物学特性初步研究

作者1991——1995年对桑树上发生的一种新害螨——柑桔始叶螨为害桑树情况和室内生活史进行了初步研究,究明该螨在桑上年可发15～17代,卵期:23～24℃5～6天。27～30℃3～4天;幼螨至成螨历期:20℃左右9～10天,23～24℃6～7天,27～28℃5～6天;成螨寿命最短13天,最长51天。雌成螨产卵前期1—3天,产卵期10—41天。每雌产卵量最高90粒,最低为12粒,总平均为40.89粒。雌雄性比为2.05:1。该螨主要在桑树主干近基部疤痕、裂缝等处越冬,4月初上树为害,5～6月形成高峰。7-9月虫口锐减。10-11月再形成小高峰直至桑树落叶。四川桔桑混载地区均有发生。     

桑园红蜘蛛的发生及防治

红蜘蛛以幼、若螨及成螨为害桑叶,幼、若螨、成螨多群集桑叶叶背,在叶脉间吸食桑叶汁液,致使在相应的叶面产生红黄色斑块.发生严重的年份,一叶上的虫数多达百头至千头.     

螨类害虫在果树上发生特点与防治方法

１发生规律与特点 适温干旱是螨类猖獗发生的重要因素,气温１２℃左右时螨类虫口开始增长;１６℃时成倍增长,２０℃以上盛发,２８℃以上时会受到抑制;相对湿度６０％～７０％最宜,暴雨对螨类有较大的冲刷作用。螨类世代历期短,在发生盛期,完成一个世代需１４ ～１６天,其中卵期５～６天,幼螨２天,若螨５～６天,成螨产卵前期１．５天左右;螨类年发生代数多,雌成螨寿命５～２８天,存在世代重叠现象。螨类多以卵和成螨在叶背面越冬,“立春”后天气转暖时越冬卵出现盛孵期,春梢转绿后,大量虫口从上年秋梢转移到春梢为害,此时…     

桑始叶螨Eotetranychus suginamesis(yokoyama)发生规律与防治研究——Ⅲ、生物学的研究

1.世代年生活史饲养方法,探索出以盛水皿膜方叶法较优,此法简单适用,操作方便,单皿养螨数量多,饲养成功率高,并适合饲养桑上多种叶螨。 2.该螨可行有性生殖和产雄孤雌生殖,发育从卵到成螨,雌螨经过幼螨,前若螨,后若螨四个螨期,雌螨产卵期平均20天左右,一雌产卵最多可达78粒,平均33粒。成虫寿命雌螨20天左右,雄螨15天左右。卵期、早春、晚秋10天以上,5、8、9三月7—9天,6月上旬—8月中旬,4天左右。 3.重庆地区年发生15—16代,夏秋高温10大左右1代,早春晚秋一个月左右1代,5月、9月15—17天左右1代第一代发育整齐,第二代起世代重叠现象明显。 4.该螨除害桑叶外,尚可取食构叶。勉强取食柘叶,蒿叶,文献尚记载取食算盘子,但未见采到材料。重庆地区、只见害桑,未见害构现象,可能是当地桑树密集,食料丰富,以桑最喜好为故。迁移扩散主要是爬行,速度因光滑变异,光滑纸面每小时爬339厘米,桑叶叶面每小时253厘米,叶背210厘米,泥沙土120厘米,干河沙70厘米。     

板栗二斑叶螨的发生与防治

遵化市板栗园 1996年始见二斑叶螨 (Ｔｅｔｒａｎｙ ｃｈｕｓｕｒｔｉｃａｅｋｏｃｈ)为害 ,1998年扩散到全市栗产区 ,部分栗园发生相当严重 ,并有为害逐年加重的趋势。1　为害特点　二斑叶螨以幼螨、若螨和成螨群集板栗芽、叶背和栗蓬 ,刺吸汁液。叶片受害初期 ,在叶片主脉两侧出现许多细小失绿斑点 ,随着为害程度加重 ,叶片严重失绿呈苍灰色 ,并变硬变脆 ,引起落叶 ,严重影响树势。该螨有结网习性 ,特别在数量大时 ,丝网可覆盖叶的背面或在叶柄与枝条间织网 ,叶螨在网上穿行和产卵。2　发生规律　一年发生 8～ 12代 ,高温干旱年份发生代数…     

桑红叶螨(Tetranychus cinnabarinus Boisduval)分布为害及生物学特性研究

本文报导四川桑红叶螨的分布为害调查和生物学特性研究结果。调查表明已涉及的全川60余个主产茧县,均有不同程度发生为害,部分县(市)已上升为当地主要害虫,严重发生时早春刚萌发新芽即不能开展,4—6月短期内大面积被害桑树一片枯褐,状如火燎,完全失去饲料价值。生物学特性研究得出该螨在四川年发生20～21代,各螨态历期,早春、晚秋,卵期12～14天,幼若螨期14～16天,盛夏、卵期3～4天,幼若螨期6～7天,一雌最多可产卵162粒,成虫寿命一般20天左右,越冬代可达4月之久。食性极广,除桑外,尚喜食豆科植物及益母草,风轮草等杂草;幼、若、成螨常聚集叶背两叶脉间叶肉部分取食为害、产卵繁殖。     

杀螨剂“克螨特”亚致死剂量对朱砂叶螨实验种群生命参数的影响

为了科学合理地使用桑园杀虫剂,采用Jackkn ife统计推断技术,在16 L、(30±1)℃、RH 75%±10%,8D、(20±1)℃、RH 65%±15%的条件下,对寄主为桑树的朱砂叶螨种群水平上的亚致死效应进行了研究。朱砂叶螨成螨经杀螨剂“克螨特”亚致死剂量(60.83 mg/L)处理后,成螨寿命降低,雌螨总产卵量显著低于对照组;处理组内禀增长率(0.272 0±0.007 5)也显著低于对照组(0.338 6±0.005 5)。     

葎草提取物对朱砂叶螨生物活性的研究

在28℃、60%～80%RH、16L∶8D的实验条件下研究了葎草乙醇和水提取物对朱砂叶螨的生物活性。结果表明,葎草乙醇提取物对朱砂叶螨有较强的触杀作用,80g/L浓度的提取物平均死亡率高达91.11%,80g/L浓度的水提物下平均死亡率51.11%;乙醇提取物对朱砂叶螨有较强的驱避作用,在浓度为10g/L的醇提物下驱避率达60%,醇提效果优于水提;乙醇提取物对朱砂叶螨成螨产卵量有较强的抑制作用,在浓度为10g/L的醇提物和水提物下,减少率分别为62.39%与47.93%。研究结果有助于朱砂叶螨的综合治理。     

扑利旺防治柑橘红蜘蛛的应用技术研究

为探索扑利旺在柑橘红蜘蛛上的应用效果,开展了扑利旺防治柑橘红蜘蛛卵室内试验以及在不同虫口基数和不同温度条件下的田间试验。结果表明：扑利旺可明显抑制柑橘红蜘蛛卵的孵化,且孵化后幼螨存活率降低,并对幼螨、若螨和成螨均有较好的防治效果。生产使用中,在虫口基数低（2-3头/叶）或春季红蜘蛛发生期,推荐扑利旺200-300倍喷雾处理或扑利旺500倍+24%螺螨酯5000倍喷雾处理;而在虫口基数高（9-10头/叶）或秋季红蜘蛛繁殖高峰期,推荐扑利旺200-300倍+ 24%螺螨酯5000倍喷雾处理来控制柑橘红蜘蛛的危害。     

浅谈果园二斑叶螨的发生与防治

近几年,由于气候异常变化和药剂使用不当,诱发了二斑叶螨的发生与蔓延。该螨不仅为害苹果、梨、桃、大樱桃、草莓等叶片,还为害玉米、花生、大豆及多种蔬菜的叶片。轻者失绿变褐,重者枯焦脱落;严重影响作物的生长发育和产量,是当前农业生产中不可忽视的一种害虫。１二斑叶螨发生规律每年发生１０余代。以雌成螨在植株根颈部、杂草根部、落叶下、覆草下及村于老翘皮、裂缝中等处越冬。幼树上的叶螨多在根颈周围的土缝中越冬。根据其种群变化规律,一年中大体可分为６个阶段。一是出蛰期。当春季平均气温达１０℃左右时,越冬雌成螨开始…     

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