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1.灰稻虱是苏南稻区每年普遍发生为害和暴发年猖獗成灾的主要害虫。由于其早在6—7月间已进入全年发生盛期,故对双季早稻和单季中稻的为害特别严重。 2.该虫的主要寄主 夏秋季为水稻Oryza sativa L.,冬春季为小麦Triticum aestivum L.、看麦娘Alopecurus aequalis Sobol.。其它寄主有稗Echinochloa crus-galli Beauv.、李氏游草Leersia japonicaMakino等十种。 3.灰稻虱在苏南稻区一年发生六代。发生时期:第一代为4月下旬—6月上旬,第二代为6月上旬—7月上旬,第三代为7月上旬—8月上旬,第四代为8月上旬—9月中旬,第五代为9月上旬—10月中旬,第六代若虫在10月上、中旬孵化,11月上、中旬以3—4龄若虫于麦田、紫云英田或沟埂杂草处越冬,翌年3月中旬—4月中旬化为成虫。 4.灰稻虱在水稻田内的消长峰态可以分为“双峰”和“单峰”两种。高峰的出现期一般总是在水稻营养状况良好的分蘖盛期和孕穗期。 5.早夏发生量的多寡,除与水稻早期栽培的面积和营养状况密切有关外,还与冬前虫口基数和1—3月间的气温等综合因子有关。6—7月间,寄生蜂、线虫和蜘蛛类等天敌的活动,对灰稻虱的增殖也有一定的抑制作用。 6.个体发育中,卵期还可凭胚胎发育的特征划分为胚盘、胚带、黄斑、反转、眼点、附肢形成和孵化等七期。各虫?
1. Gray flies are common pests in the southern Jiangsu rice area and are the main pests that cause rampant outbreaks in southern Jiangsu. As early as June-July has entered the peak throughout the year, so the two-season early and mid-season single-crop damage is particularly serious. 2. The main host of this pest is rice Oryza sativa L. in summer and autumn, wheat Triticum aestivum L. in winter and spring, and Alopecurus aequalis Sobol. Other host barnyardgrass Echinochloa crus-galli Beauv., Le grass tournament Leersia japonicaMakino other ten. 3. Gray louse occurred in southern Jiangsu rice area six generations a year. Occurred period: the first generation of late April - early June, the second generation of early June - early July, the third generation of early July - early August, the fourth generation of early August - mid-September, the first The fifth generation is from the first ten days of September to the middle of October. The sixth generation of nymphs hatch in mid-October and mid-October. In the upper and middle of November, 3-4-year-old nymphs overwinter in wheat fields, Mid-month - mid-April into adult. 4. The growth and decline of the gray flies in paddy fields can be divided into two kinds: “double peak” and “single peak”. The peak of the emergence of the rice is usually always in good nutritional status of tillering and booting stage. Except early rice cultivation area and nutritional status are closely related, but also with the pre-winter insect population base and January-March temperature and other comprehensive factors. From June to July, activities of natural enemies such as parasitoid, nematode and arachnids also inhibited the growth of the gray flies. 6. Individual development, the egg can also be divided into embryonic development characteristics of embryo, embryo, macular, reversal, eye point, appendage formation and hatch seven. Each bug?