甘蔗长蝽发生规律与防治技术研究

A Study on the Bionomics and control of Cavelerius saccharivorus Okajima)

甘蔗长蝽已从南北移至吉安蔗区的万安、泰和、吉安三县的10个乡镇,北限为吉安县横江镇,即26°45′N,114°48′E。甘蔗长蝽在吉安地区发生不完整3代,以第二代卵在蔗蔸和蔗种及蔗残茎梢上越冬,是翌年主要虫源,其生长发育的最适温度为24～27℃;相对湿度为80％左右,并详细阐明了各虫态历期、发育起点与有效积温。径频次概率拟合及聚集度指标测定,甘蔗长蝽空间分布呈聚集型,且在成虫交尾高峰和高龄若虫阶段有过高聚集现象,抽样方法以“Z’字型为好,最适抽样量为n_(成虫)=27.737/m+3.265;n_(成虫)=22.195/m+10.211。初步确定甘蔗糖份形成期长蝽的防治指标为6～10头/株,其经济充许水平(L)为2％,药剂防治适期为越冬代若虫高峰和第一代成虫高峰,并对防治策略进行了探讨。

Cavelerius saccharwarus okajima has shifted from south to ten sugar cane growing villages and towns in Wanan , Taihe and Jian counties with Hengjiang town( 26°45′ N, 114°48′ E)being the farthest north end. It had three incomplete generations in Jian area and overwintered in the stubble of sugarcane with the second generation ova which was the main source of the pest next year. The optimum temperature for development ranged from 24℃ to 27℃, and relative humidity was about 80%. Furthermore , duration periods of various inset stages, the temperature threshold for development and effective thermal constant were studied. Data analyses showed that, the spatial pattern of saccharwarus belonged to the aggregated distribution, and extreme aggregation took place in mating peak and old instar nymph period. 'Z' from mothed was suitable for sampling. Theoretical sampling numbers may be given by: The primary study revealed that economic threshold at sugar forming stage should be 6 - 10 nymph or adults per plant with 2% of the yield being lost. The optimum time for its control was peak periods of overwintering generation nymph and the first generation adults. Besides, the control tactics were proposed here.