柑桔园矢尖蚧化学防治策略

ON THE CHEMICAL CONTROL STRATEGIES OF ARROWHEAD SCALE UNASPIS YANONENSIS IN CITRUS GARDEN

1995～1998年对柑桔的矢尖蚧重发园、一般发生园和始发园等不同为害程度的柑桔园的化学防治技术进行了比较详细的研究。建议重发园防治矢尖蚧实行春季越冬代+第1代防治法,一般发生园实行第1代1次防治法,始发园实行根治法。一般发生园的防治指标是越冬代雌成虫基数超过冬季1头/梢或春季0.5头/梢,低于该指标的轻发园天敌就能自然控制矢尖蚧。春季越冬代宜用松脂合剂8～10倍防治,第1代1龄若虫峰末期宜用40％速扑杀EC或40％氧乐果EC 1500倍+95％机油乳剂100倍或25％扑虱灵WP1500倍防治。

Investigations of rational chemical control techniques in citrus orchard having seriously, generally and initially damaged by arrowhead scale Unaspis yananensis (Kuwana) was carried out in 1995- 1998, and the control strategies separately suitable to diferent damage levels of this insect pest were proposed. In seriously damaged orchard, the chemical control was focussed both on overwintering and first generations, with rosin-soda compound against overwintering generation in spring and a mixture of supracide (or omethoate) and lubricant emulsion (or buprofezin) at the terminal of peak occurrence period of 1st instar nymph in 1st generation. That in generally damaged orchard was on 1st generation only with the same mixture mentioned above, and the action thresholds in winter and spring were 1.0 and 0.5 overwintering adult per twig end, respectively. Whilst in initially damaged orchard, the chemical control should be cancelled for promosing the suppression of natural enemies to keep U. yanonensis under control.