玉米田草间小黑蛛空间格局及其抽样技术研究

据笔者调查,草间小黑蛛(Erigonidium graminicoa)是鲁中南山区玉米田的优势天敌之一.玉米田从6月中旬至9月中旬草间小黑蛛的数量占全田蜘蛛总量的43.2%,对玉米螟(Ostrinianubilalis)早期幼虫、蚜虫、叶蝉等主要害虫的捕食能力较强.关于草间小黑蛛的生物学特性及在棉田内的空间格局,国内已有报导.笔者现将1990～1991年对玉米田草间小黑蛛的空间格局研究结果进行报导,旨在为进一步研究该蛛在玉米田内的空间格局及开展保护利用提供科学依据.     

鞍形花蟹蛛对八点球腹蛛的捕食功能反应及其数学模拟的初步研究

我们在实验室内人工条件下,对鞍形花蟹蛛捕食八点球腹蛛的功能反应进行了初步研究.鞍形花蟹蛛的捕食功能反应是随猎物密度的增加而增大,最大捕食量约为2.5950头,最佳寻找密度为2.1110头.而随其自身密度的增加而减少,随两者密度的增加,相互干扰越显著,捕食作用下降.还建立了参数方程和模拟模型.该参数方程能在一定程度上描述雌成蛛对八点球腹蛛的捕食作用.     

封面、封底照片: 蜘蛛的捕食

蛛形纲动物的种类和数量很多,它们的主要特征是头胸部有６对附肢,第一对为螫肢,末端有螯爪,是分泌蛛毒的部位,其分泌的蛛毒具有麻痹猎物的作用;第二对为脚须,或称为触肢;其余四对为步足。具有这种特征的动物不仅仅是人们熟悉的蜘蛛,还有好多动物也具有这样的特征,如与人类有密切关系的蝎、蜱、螨等。蜘蛛是肉食性动物,它们有两种捕食方式：结网捕食和游猎捕食。１结网捕食 自然界中比较常见的圆蛛（见封底图１）,它们喜欢在屋檐下或室内的角落结成圆网,圆网的外围密布蛛丝,丝上有粘滴,一旦昆虫碰到网上就被粘住,圆蛛迅速用…     

黑斑卷叶蛛生物学特性的研究

黑斑卷叶蛛(Dictyna felis Boesenberg et Strand 1906),在山东省青州市一年可发生两代,以若、成蛛越冬.若蛛经4～5次蜕皮发育为成蛛,雌雄蛛可多次交配,一生产卵囊3～6个,单雌产卵量平均39.6粒,孵化率平均60.85%,世代平均历期85.30天,平均寿命155.26天,性比(?):(?)=1.61:1.耐饥力与有无水分供应、温度高低及发育阶段有关,在相同条件下,成蛛的耐饥力大于幼蛛.     

梅园节肢动物群落优势种分析

应用系统调查和能流量法分析了梅园节肢动物群落优势种,结果表明:不论数量和能流量分析,梅园节肢动物群落的主要害虫优势种均为朝鲜球坚蚧和桃蚜;而天敌优势种数量和能流量分析分别为黑缘红瓢虫、红点唇瓢虫和黑缘红瓢虫、草间小黑蛛.     

芦苇卷叶蛛和黑斑卷叶蛛幼蛛各龄期比较

本工作是在研究芦苇卷叶蛛(Dictyna arundinacea) 和黑斑卷叶蛛(Dictyna felis)生物学特性的基础上进行的.结果表明,二者虽同为卷叶蛛科(Dictynidae)卷叶蛛属(Dictyna),形态特征比较相似,但黑斑卷叶蛛5龄以前的幼蛛个体比芦苇卷叶蛛幼蛛个体大,体色也深,其中腹部背面的斑纹、颜色是区别二者各龄期幼蛛的主要特征.     

小菜蛾主要捕食性天敌种类及捕食功能研究

研究了小菜蛾主要捕食性天敌种类及其捕食功能.经过调查试验,已发现盐城郊区菜田小菜蛾捕食性天敌种类共有22种,其中包括瓢虫、蜘蛛、隐翅虫、步甲、螳螂、蠼螋、盲蝽、花蝽、草蛉、蚂蚁等种类.在盐城市盐都地区,小菜蛾捕食性瓢虫优势种为七星瓢虫、异色瓢虫、六斑月瓢虫、黄斑盘瓢虫;蜘蛛优势种为黑腹狼蛛,拟环纹狼蛛;蠼螋中的环足肥螋为优势天敌.在25℃实验条件下,研究了异色瓢虫的雌成虫、雄成虫及其四龄幼虫捕食2～3龄小菜蛾幼虫的捕食功能,其功能反应类型为HollingⅡ型,功能反应的数学模型为Na=0.5980Nt/l+0.5980×0.0735Nt(雌成虫),Na=0.2584Nt/l+0.2584×0.0199Nt(雄成虫),Na=0.7080Nt/l+0.7080×0.0228Nt(四龄幼虫),同时研究了异色瓢虫的实验种群繁殖特征生命表.净生殖R0为32.25,世代周期T为37.46d,内禀增长率Rm为0.0978,周期增长入为1.1027.     

河北山区枣园蜘蛛群落结构研究

通过对河北山区枣园蜘蛛的调查,发现有13科53种蜘蛛.优势科为蟹蛛科（Thomisidae）、园蛛科（Araneidae）、狼蛛科（Lycosidae）和皿蛛科（Linyphiidae）.优势种为：三突艾奇蛛（Ebrechtella tricuspidata）、星豹蛛（Pardosa astrigera）、草间钻头蛛（Hylyphantes graminicola）和六痣蛛（Araniella displicata）.分析了蜘蛛生物学特点、植被情况、人事活动对蜘蛛群落结构和优势种群消长变化的影响,分析的结果可为枣园害虫的综合防治提供参考.     

豹蛛消化稻纵卷叶螟速率的测定

研究捕食功能需确定天敌1天之内捕食多少头害虫.本文描述了用血清法测定豹蛛对稻纵卷叶织成虫和幼虫的消化速率,即测定Dempster的公式 E=PmT/t中的t值.其结果.捕食成虫的标准速率为“1”,擁食高龄幼虫的标准速率为“2”.     

具有偏嗜行为的龟纹瓢虫——麦蚜系统的定性分析

本文根据龟纹瓢虫对麦蚜若蚜与成蚜的捕食具有不同的Holling Ⅱ型功能反应,建立了具有偏嗜行为的龟纹瓢虫——麦蚜系统,研究了该系统的全局稳定性和极限环的存在性,并应用Lienard方程的技巧,证明了该系统存在唯一的极限环.     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…