一种捕食性螽蟖—黑背小绿螽的研究

黑背小绿螽的成虫、若虫均咬食三化螟卵块;并捕食白螟、斜纹夜蛾的卵;叶蝉、稻虱、稻蝗的低龄若虫。在南宁、贵县等地一年发生两代,以卵越冬,卵散产于茭白、姜苗、禾本科杂草等的叶鞘内侧及稻兜株间。用人工配制的代饲料饲养,所得的成虫能继代繁殖。在稻田及时补充散放一定数量的适龄虫体,对控制三化螟害虫有一定的作用。

STUDY ON A PREDACIOUS KATYDID, CONOCEPHALUS SP.

(1) The Katydid, Conocephalus sp. is recognized as a new predator of the yellow rice borer, Scirpophaga incertula Wlk. in Guangxi. It preys on the egg masses of S, incertula, Scirpophaga innotata and Prodenia litura in paddy fields. Leafhoppers, planthoppers and the young nymphs of grasshoppers are also used as preys.(2) The insect has two generations per year in Nanning and Guixian of Guangxi Province. It hibernates in egg stage and the eggs are deposited singly or in small numbers on the inner surface of the leaf sheaths of Zizania latifolia Turcz., Zingiber officinale Rose, and wild Gramineae grasses. They have also been found between the stalks of rice stubbles. The overwintered eggs hatch in mid-April and the adults of 1st generation emerge in the mid-and late-June.The adults of 2nd generation can be found from late-August to the end of the year.(3) This insect can be reared successfully on artificial diets. The diet-fed adults develope nor-mally, They can mate and reproduce successively.(4) If large quantities of this Katydid adults or nymphs (which are in a suitable instar) are released in the field at the right time, the preying rate upon egg masses of yellow rice borer could be increased. It seems that such a treatment may be usable for the control of rice borers.