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<正>随着我市蚕桑生产的发展,桑病虫防治工作越来越重要,难度越来越大,特别是近几年,每年都有一些危险性害虫严重发生,给蚕桑生产带来威胁.本文就近年我市桑园害虫发生特点、发生原因进行分析,探讨防治主要虫害的对策.一、发生特点及原因分析近几年我市桑园害虫的发生主要有以下几个特点:一是害虫的种类逐年增多;二是春季桑园害虫的发生有上升趋势;三是鳞翅目害虫的危害逐年加重,每年都有一些害虫秋期暴发;四是桑橙瘿蚊的危害面广量大,几乎 相似文献
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随着蚕桑业发展,我县桑园由高干乔木零散式结构,逐步演变成现在成林化低干密植群体式结构。桑树虫害发生也由种群数量少、发生量小、危害程度轻,发展到现在种群数量多、发生量大、危害重。６０～７０年代,我县蚕农基本上没有桑树虫害防治习惯和经验。８０年代随着桑园面积扩大,桑树虫害发生也越来越严重,已严重影响到蚕桑生产效益,到了非治不可程度,但当时大多是由蚕农自愿自由式防治。进入９０年代,桑树害虫危害日趋猖蹶,给蚕桑生产造成了巨大损失,严重威胁到蚕桑生产发展,在政府和技术部门积极宣传组织推广下,桑树害虫统防统… 相似文献
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为了有效防治辣椒虫害,提高辣椒产量和质量,本文总结了几种辣椒常见虫害的田间识别与防治方法,从害虫的形态特征、为害特性、发生特点及防治措施几方面介绍了桃蚜、茶黄螨、烟青虫的识别与综合防治措施. 相似文献
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才仁卓玛 《养殖与饲料．饲料世界》2010,(7):82-83
1草原虫害防治历程
长期以来,青海省草地保护工作者一直在同危害草原的害虫进行较量。随着科学技术的进步和社会生产力的发展,防治草原虫害的技术和手段不断得到提高和改进;而草原虫害的种类、发生危害规律也在不断发生变化。 相似文献
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近几年来 ,不少种植于红壤山地的成龄青、花出现桃蚜虫、桑白蚧、桃蛀螟和李小食心虫等害虫恶性循环发生现象。虽然用药量逐年加大 ,但防治效果并不明显 ,致使成本增加 ,经济效益较差。 1998年以来 ,笔者调查了部分虫害严重的园 ,探究其虫害严重的原因 ,并提出综合防治措施。1 成龄树虫害严重的原因1 1 越冬虫口基数大 不少果农冬季清园不彻底 ,未刮除树皮、枝干上的越冬虫体 ;未彻底剪除被害严重的枝条 ;冬季清园未喷石硫合剂。1 2 预测预报不到位 不少果农未开展简易虫情测报 ,仍采用见害虫才喷药的传统习惯。1 3 喷药防治… 相似文献
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草原虫害防治是农业部较早大规模组织开展的防灾减灾工作之一。在长期的实践工作中,草原虫害防治始终坚持“预防为主,综合防治”的植保方针,逐步建立了“以生物防治为主,化学防治为辅”的技术路线。2002年起,全国畜牧总站在全国牧区组织开展了《草原虫害生物防控综合配套技术推广应用》项目。该项目的实施带动了全国的草原害虫防治,为草原可持续发展提供了技术支撑。本文以该项目的进展为基础,简要总结介绍了草原害虫防治的实施背景、开展情况及建设成果,包括以生态系统平衡原理为指导,对虫害监测预警、生物防控和施药技术等进行集成创新与组装配套,使草原害虫密度长期控制在经济阈值以下,实现草原生态系统平衡等。 相似文献
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高致病性禽流感免疫的管理环节 总被引：1，自引：0，他引：1
一 严管疫苗生产环节
兽用生物制品生产厂家多,品种较多,质量不一,免疫效果各异,特别是高致病性禽流感疫苗,由于生产时间较短,疫苗质量不够稳定,副作用较为严重,包装规格单一,技术服务滞后．严重地影响了高致病性禽流感的免疫效果。如有的厂家疫苗生产的批准文号和疫苗产品不相符。有的中试产品或有临时批准文号的疫苗,不按规定范围随意大面积推广,有的同一厂家生产的疫苗,不同批次质量不一,免疫效果差异较大。 相似文献
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Transgenic pigs for xenotransplantation for humans] 总被引：1，自引：0，他引：1
H Niemann 《DTW. Deutsche tier?rztliche Wochenschrift》1999,106(4):141-146
Transgenic livestock have been generated via microinjection of DNA-constructs into pronuclei of zygotes. However, efficiency is low and only 1-3% transgenic offspring are to be obtained. Integration of the transgene occurs at random and expression is independent from the number of integrated copies but can be affected by the integration site. To overcome the shortage of human organs, transgenic pigs have been generated that express human complement regulatory genes. This approach enables to overcome the hyperacute rejection response as shown by an average survival rate (40-90 days) of the immunosuppressed primate recipients receiving a heart from a transgenic pig. It is expected that transgenic pigs would be available as organ donors in the next 5-10 years. A major prerequisite, however, is the prevention of the potential transfer of pathogenic microorganisms, in particular porcine endogenous retroviruses (PERV). Improvements of the efficiency in the generation of transgenic pigs will be achieved by the use of genetically modified donor cells in nuclear transfer technology (cloning). 相似文献
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Strategies for Using eFSH for Superovulating Mares 总被引：1，自引：0，他引：1
Patrick M. McCue DVM PhD Melissa Patten BS David Denniston PhD Jason E. Bruemmer PhD Edward L. Squires PhD 《Journal of Equine Veterinary Science》2008,28(2):91-96
The standard treatment for superovulation of mares is to administer equine follicle-stimulating hormone (eFSH) for 4 to 5 days to stimulate multiple follicles and human chorionic gonadotropin (hCG) to induce synchronous ovulations. Objectives of this study were: (1) to determine whether a short-term (3-day) eFSH treatment protocol would result in similar ovulation and embryo recovery rates compared with the standard eFSH protocol; (2) to determine the efficacy of a decreasing dose of eFSH (step-down protocol) on ovulation rate and embryo recovery; (3) to compare the efficacy of hCG and recombinant equine luteinizing hormone (reLH) for inducing ovulation in FSH-treated mares; and (4) to compare embryo recovery rates and embryo size when mares are flushed at 6.5 or 7.0 days after ovulation. Forty light-horse mares were used in 2005 (experiment 1) and 20 different mares were used in 2006 (experiment 2). In experiment 1, mares were randomly assigned to one of three treatment groups: (1) untreated controls, (2) standard eFSH treatment (12.5 mg intramuscularly twice daily), and (3) 3-day eFSH treatment. In experiment 2, mares were randomly assigned to one of four treatments: (1) untreated controls, (2) standard eFSH protocol, (3) 3-day eFSH treatment, and (4) step-down eFSH treatment (12.5 mg twice daily day 1, 8.0 mg twice daily day 2, 4.0 mg twice daily day 3). Within each treatment, mares were given either hCG (2,500 IU) or equine LH (750 mg, EquiPure LH; reLH) to induce synchronized ovulations. Embryo recovery was performed either 6.5 or 7.0 days after ovulation. In experiment 1, numbers of preovulatory follicles and ovulations were less for mares in the 3-day treatment group than the standard group, but were greater than for controls. Embryo recovery per flush was higher in the standard group (2.6) than the 3-day eFSH treatment (0.8) or control groups (0.8). In experiment 2, the number of preovulatory follicles and number of ovulations were greater in the standard and 3-day treatment groups than in control and step-down groups. The percent embryo recovery per ovulation and mean embryo grade were similar for all groups; however, the embryo recovery per flush was higher for mares in the standard treatment than controls (1.3 vs 0.6) but was similar to the 3-day (1.1) and step-down (0.8) treatments. Embryo recovery was similar for flushes performed on days 6.5 and 7.0 post-ovulation. The percentage of control mares ovulating within 48 hours in response to hCG or reLH was similar. In contrast, a higher percentage of eFSH-treated mares ovulated within 48 hours in response to reLH than hCG (92% vs 71%). In both years, the 3-day eFSH treatment protocol resulted in a greater number of preovulatory follicles and a greater number of ovulations than untreated controls. Unfortunately, the increased ovulation rate for mares administered eFSH for 3 days did not result in a greater number of embryos recovered per flush in either year. Use of a step-down eFSH treatment protocol resulted in fewer preovulatory follicles, fewer ovulations, and fewer embryos as compared with the standard eFSH treatment. In conclusion, the standard eFSH treatment resulted in a greater embryo recovery rate per cycle than either the 3-day or step-down treatment protocols. Recombinant equine LH was more effective than hCG in causing ovulation in eFSH-treated mares. 相似文献