Abundance of arthropods on the branch tips of the invasive plant, Rosa multiflora (Rosaceae)

Rosa multiflora Thunb. (Rosaceae) is an invasive species in the USA, where it grows in pastures and wooded areas. A disease of unknown etiology, rose rosette disease (RRD), infects R. multiflora and other Rosa spp. The goal of this research was to determine the effects of habitat and disease symptoms on the abundance of Phyllocoptes fructiphilus Keifer (Acari: Eriophyidae) , the presumed vector of RRD, and other arthropods on R. multiflora . We collected branch tips from healthy R. multiflora plants growing in the sun and shade, as well as RRD-infected R. multiflora growing in the sun. The samples were collected from June 2002 to April 2004 from three sites in Iowa, USA. The samples were collected approximately every 2 weeks during the summer, monthly during the fall, and once during early spring. The fall samples were only taken from RRD-infected plants because they retain leaves throughout the winter. We found that P. fructiphilus was present on diseased and healthy R. multiflora growing in the sun and on healthy R. multiflora growing as understory plants under a tree canopy (shaded), but the greatest numbers were observed on the diseased plants growing in the sun. Several other mite species, both predatory and phytophagous, Chaetosiphon sp. aphids, and the thrips species, Frankliniella exigua Hood and Neohydatothrips variabilis Beach, occur in the same plant microhabitat as P. fructiphilus . This is the first study to document the presence of additional arthropods in the same microhabitat (branch tips) as P. fructiphilus . Future research needs to isolate and identify the causal agent of RRD so it can be confirmed that, of the many arthropods feeding on R. multiflora , only P. fructiphilus vectors RRD.     

单·吡啉防治水稻中后期多种害虫应用技术研究

水稻中后期是多种害虫并发时期,也是药剂进行总体防治的关键时期。为此,我们经过反复试验研究开发了一种新型稻田主要害虫总体防治的理想药剂──单·吡啉。在稻飞虱二、三龄若虫高峰期或螟虫卵孵高峰期,每666．7m2用单·吡啉100g对水常现喷雾,适期用药1次,对稻飞虱、稻纵卷叶螟、二、三化螟的防效均达95％左右,显著优于目前推广的药剂,是当前水稻害虫总体防治的理想药剂。     

Diversification of diseases affecting herb crops in Israel accompanies the increase in Herb crop production

During the last 15 years there has been a significant increase in both field and greenhouse herb crop production in Israel. Many new species and cultivars are being grown. The increase in herb production has been accompanied by an increase in the occurrence of known soilborne and foliar pathogens along with some new diseases and new forms of existing diseases. Apart from the expansion of herb crop production, the changes in cultural and harvesting practices are likely contributors to the increase in disease incidence.     

转抗虫基因烟草植株对棉铃虫幼虫抗性能力的研究

作者等对转CpTI基因烟草植株进行了抗棉铃虫能力的评估。用死亡率、蜕皮指数、平均体重、生物总量和植株受害程度等5个指标,综合判断转基因植株的抗性水平。结果表明,检测的10株转基因植株中对棉铃虫表现为高抗、中抗的各占4株,低抗的占2株。高抗植株测试虫校正死亡率达90％以上,中抗植株测试虫校正死亡率达75％以上,差异显著,在高抗植株上生长的测试虫蜕皮指数低于标准的30％,总虫重仅为对照的1％,中抗植株上生长的测试虫蜕皮指数是标准的30％～40％,总虫重为对照的3％～7％。综合分析结果表明,高、中抗植株对棉铃虫的抗性明显。     

马尾松毛虫寄生天敌—红尾追寄蝇的生物学研究

红尾追寄蝇是马尾松毛虫幼虫期的重要寄生天敌,主要寄生5～6龄松毛虫,第1、2、3代松毛虫寄生率分别为21.37. 44.95和0.71％。该蝇在湖南年发生5～6代,以蛹在土内越冬。95％以上的卵产于寄主胸足上,每寄主体上的着卵量为1～33粒,最多出蝇11头。当着卵量在7.5～20粒时,寄主陆续在幼虫和蛹期全部死亡;2.5粒时有3％的寄主仍能存活。寄蝇种群数量变动与当年5月气温成正相关,与7年下旬至8月上旬气温成负相关。     

八斑球腹蛛对褐飞虱的捕食作用

八斑球腹蛛对褐飞虱的种群数量有一定的控制作用。田间日捕食量为0.25～1.88头。试验室内,其功能反应可用Ⅱ型和Ⅲ型反应模型拟合;当空间容积增大时,为典型的S形Ⅲ型。为此,虫蛛比应是随褐飞虱密度、龄期结构和防治指标等变化的函数。     

六索线虫防治小地老虎的小区试验

本文报道利用六索线虫的寄生前期幼虫防治小地老虎幼虫的小区试验结果。当释放的六索线虫与小地老虎幼虫之比为100:1和150:1时,释放5天后寄生率达50～63.64％。     

外来入侵生物-B型烟粉虱的发生规律和防治技术

通过形态学、生物测定、mtDNA COI基因分子标记和分子生态学研究,证实了近年在我国广大地区发生的B型烟粉虱为外来入侵生物,探讨了爆发成灾机理,明确了基础生物学特性和发生规律,提出了以隔离、净苗、诱捕、寄生和调控为核心的IPP控制技术体系,应用结果综合效益显著。     

Cyperus esculentus L. — A new weed in Israel

Cyperus esculentus L., a cosmopolitan noxious weed, has been recorded for the first time in an agricultural irrigated field in Israel. Hand-weeding, herbicides and soil disinfestation methods were only partially effective in controlling the weed. The distribution map of the weed is unknown, and it is unclear how the weed has been introduced into Israel. We estimate thatC. esculentus has a high risk potential to spread further and cause damage to Israeli agriculture, and therefore its spread should be restricted. http://www.phytoparasitica.org posting May 18, 2005.     

烟蚜茧蜂蛹期耐冷藏性研究

在(25±1)℃、RH85%、光照∥黑暗=16h∥8h条件下僵化1～5d的僵蚜,置5℃冰箱中保存,结果显示:僵化3d蚜虫中烟蚜茧蜂平均羽化率最高(72.33%～85.33%),僵化2d蚜虫中烟蚜茧蜂羽化率次之(65.67%～81.33%),僵化4d、5d蚜虫中的烟蚜茧蜂羽化率最低(<70%);僵蚜低温冷藏对羽化出的烟蚜茧峰雌蜂寄生能力无显著影响,各处理中羽化出的雌蜂平均寿命减少皆小于1d。