小麦吸浆虫化蛹羽化与土壤湿度及温度的关系

小麦吸浆虫是一个喜湿性昆虫．笔者观察分析了淮北麦区对该虫发生影响最大的是３月中旬至５月上旬的土壤湿度．此段时期５厘米土壤含水量低于２０％，化蛹即受到抑制；低于１５％便不能化蛹羽化，且能造成成虫虫体大量死亡。不同时段的低湿对该虫的影响作用是不一样的。中期低温会使化蛹进程中断，出现羽化双峰现象，后一峰的大小又取决于旱情出现和解除时间的早退，若早则大，反之则小．温度的高低也可影响化蛹羽化期的早迟。     

美国白娥越冬代虫羽化规律及产卵习性的研究

对美国白蛾越冬代成虫羽化规律及产卵习性进行了研究,找出了影响羽化及产卵的关键气候因子。即连续５ｄ日平均气温达到１２℃、ＲＨ在６８％以上时,越冬代成虫开始羽化;连续５～６ｄ日平均气温高于１６℃时,出现羽化高峰;当日平均气温低于１５．７℃时,出现羽化低峰。雄成虫比雌成虫羽化始期早８ｄ,羽化末期晚５ｄ;雄成虫趋光性和飞翔能力强于雌成虫,但存活时间短于雌成虫;雌成虫的产卵量受产卵环境影响,不交尾的雌成虫产     

枣桃六点天蛾Marhumba gaschkewitschi gaschkewit …

枣桃六点天蛾年发生２代,以蛹在表土层越冬,越冬代蛹翌年５月上旬开始羽化,５月下旬～６月上旬为发生盛期。第１代成虫７月上旬羽化,７月中下旬为发生盛期。幼虫经６龄。４龄开始为暴食期。幼虫对枣叶利用率为４７．５５％,排粪率为３７．４％。粪便含水量１～４龄占４９．５４％,５～６龄占５５．５６％。幼虫排粪共１３３５粒,共重４６３９ｍｇ。成虫趋光性强。     

小地老虎室内连续饲养12代的化蛹率、羽化率和性比观察

在实验室内连续饲养12代小地老虎Agrotis ypsilon(Rottemberg),对其化蛹率、羽化率和性比进行了观察,结果表明,随着饲养时间的延长,小地老虎的化蛹率和羽化率在不断地下降,化蛹率从第1代的91.32%下降到第12代的53.37%,从第3代开始差异达到显著水平;羽化率从89.59%下降到57.93%,但在第1-6代之间差异不显著,从第7代开始差异达到显著水平;其性比始终在0.45-0.56之间上下波动,差异均未达到显著水平.     

空气和土壤湿度对南瓜实蝇存活的影响

采用室内湿度配比的方法研究了空气和土壤湿度对南瓜实蝇存活的影响,结果表明土壤相对含水量和空气湿度等有关湿度方面的条件对南瓜实蝇蛹的羽化和成虫的存活有显著影响.相对含水量在20﹪-60﹪之间蛹的羽化率较高,当土壤相对含水量达到100﹪时,南瓜实蝇蛹不能羽化.1日龄蛹经干燥处理8d后羽化率降低至28.89﹪.空气湿度对成虫存活也有显著影响,随着干旱和高湿胁迫时间的延长,成虫的死亡速率逐渐加快,但是干旱条件下的抑制效果更显著.     

光周期对麦红吸浆虫化蛹羽化的影响

通过不同光周期对麦红吸浆虫化蛹羽化的影响的试验及田间粘捕观察。结果表明:以6、9、12小时的光周期处理的麦红吸浆虫发育进度较快,而且整齐。麦红吸浆虫羽化率的总趋势是随着光周期延长而提高的。在各处理中,都有部分不化蛹的滞育幼虫。田间扣笼粘捕、网捕的羽化率和室内各处理羽化率平均值基本是一致的。     

与温度有关的几个现象

温度与味道 经科学家的大量研究证实,温度不同时,人们所吃食品的感觉是不一样的.如,甜味食品在37℃左右感觉最甜,高于或低于这个温度,甜味就会变淡;酸的东西在10-40℃之间,其味道基本不变;咸味和苦味食品,则是温度越高,味道越淡.     

噪声真的百害无益吗?

温度与味道经科学家的大量研究证实 ,温度不同时 ,人们所吃食品的感觉是不一样的。如 ,甜味食品在 37℃左右感觉最甜 ,高于或低于这个温度 ,甜味就会变淡 ;酸的东西在 1 0 - 4 0℃之间 ,其味道基本不变 ;咸味和苦味食品 ,则是温度越高 ,味道越淡。根据温度与味道的关系 ,可将食     

枯叶传奇

这可不是一片枯叶,它是电蛱蝶的蛹.在这之前,它曾是一条威武的幼虫,头上长长的弯角,足以让天敌望而生畏.幼虫化蛹后,只能挂在枝头等待羽化.这是最危险的阶段,所以电蛱蝶把蛹伪装成不起眼的枯叶就安全多了.大约一周的时间,"枯叶"裂开,一只翅膀上点缀着蓝白色闪电纹路的蝴蝶羽化了.它就是电蛱蝶的成虫.     

应试·应赛·应付·应然

一个专业化日臻成熟的教师。要蛹破三层茧缚．羽化一种“蝶”境。     

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?     

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.     

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…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.