三唑磷毒杀水稻主要害虫的作用特点及应用技术

Action Traits of Triazophos on Insect Pests in Rice Fields and Techniques for Application

1991～ 1 997年 ,通过室内生测和田间多点试验示范 ,系统分析了三唑磷对水稻三化螟、二化螟和褐飞虱的触杀活性、对稻株的渗透性、胃毒作用和杀卵活性、持效期以及田间效果。结果表明 :1三唑磷对三化螟、二化螟蚁螟的接触 L D5 0 (× 1 0 - 4 μg)分别为每头 0 .6 1 82、0 .41 6 8,远远低于甲胺磷相应的 L D5 0 值 1 4 .7732、1 7.80 2 9,对 3龄褐飞虱的 L D5 0 值与甲胺磷相近 ,对 5龄褐飞虱的触杀活性低于甲胺磷 ;2三唑磷对稻株的渗透性和对三化螟的胃毒作用强 ,喷药后 1 d、3d的渗透杀虫效果均为 1 0 0 % ;3三唑磷防治三化螟的持效性长 ,5 0 0 mg/ L 药后 1 0 d接虫的杀虫效果仍达 86 .7% ,而甲胺磷 1 0 0 0 mg/ L 药后 3d效果降为 0 ;4三唑磷 5 0 0～ 1 0 0 0 mg/ L 对三化螟前期淡黄色卵的杀死率为 71 .3%～ 73.2 % ,对后期黑色卵的杀死率为 78.3%～ 99.5 % ;5 2 0 %三唑磷乳油 2 .2 5 L/ hm2对三化螟和二化螟枯心防效均在 90 %以上 ,高于杀虫双 ,但对褐飞虱的防效差 ,明显低于甲胺磷 ,3.75 L/ hm2 对三化螟白穗的防效也在 90 %以上 ;6三唑磷对三化螟防效高而稳定 ,但对褐飞虱、稻纵卷叶螟效果差 ;

Efficacy of triazophos on major insect pests in rice fields were evaluated by bioassay and field experiment The medial lethal dose(LD 50 ) of triazophos against Scirpophaga incertulas and newly hatched Chilo suppessalis were 0 6182×10 -4 μg and 0 4168×10 -4 μg per individual pest respectively which were significantly lower than those of methamidophos(14 7732 and 17 8029),respectively,which indicated triazophos had higher contact toxicity to stem borer than methamidophos.At the same time triazophos had lower contact toxicity against Nilaparvata lugens than methamidophos.Permeability of triazophos into the stem and sheath of rice and high stomach toxicity of triazophos to Scirpophaga incertulas were observed.Residual efficacy of 500 mg/L triazophos on Scirpophaga incertulas was 86 7%,10 days after triazophos sprayed,while that of 1 000 mg/L methamidophos droppped to 0 after 3 days The corrected mortality of early yellow eggs and late black eggs with 500～1 000 mg/L triazophos reached 71 3%～73 2% and 78 3%～99 9%,respectively.Plot experiment showed that 2 25 L/hm 2 and 3 75 L/hm 2 20% triazophos (EC) were effective on dead hearts and white heads caused by stemborer.Infieldevaluation,triazophos had higherefficacyon the3rdgeneration stem borerthan it did on leaf roller and planthopper.Toxicity of triazophos to natural enemy(spider)was lower than dimehypo but higher than monosultap