常用杀螨剂与顶孢霉Ahy1菌株的相容性及协同作用

摘要

为了筛选与顶孢霉菌株相容的化学杀螨剂,本文采用孢子萌发法和菌丝生长速率法,测定了哒螨灵、虫螨腈和螺螨酯对顶孢霉孢子萌发和菌丝生长的影响及协同效应.结果表明:哒螨灵、甲氰菊酯、四螨嗪、氟虫脲、螺螨酯、虫螨腈、螺虫乙酯在不同浓度下对顶孢霉孢子萌发和菌丝生长均有不同程度的抑制作用,哒螨灵、虫螨腈、螺螨酯与顶孢霉混用对二斑叶螨有一定的协同作用.哒螨灵、虫螨腈、螺螨酯在高浓度下(25 μg/mL、0.83 μg/mL、60 μg/mL),对顶孢霉孢子萌发的抑制率分别为27.67％、27.83％和29.22％,对菌丝生长抑制率分别为20％、18％和18％,抑制作用较低,有较好的相容性；25 μg/mL哒螨灵、0.83 μg/mL虫螨腈、60 μg/mL螺螨酯与含孢量为l×106个/mL顶孢霉复配处理二斑叶螨11d,对二斑叶螨的致死效果明显大于单用顶孢霉的处理,3种药剂与顶孢霉复配剂对二斑叶螨的半数致死时间(LT50)分别为5.38、5.41、5.79d,较单用半数致死时间缩短了4.19、4.16、3.78d,提高了顶孢霉的杀螨速度.%In order to screen chemical acaricides of comparatively high compatibility with A. hansfordii, the effects of pyridaben, chlorfenapyr and spirodiclofen on conidial germination and mycelial growth of Acremonium hansfordii and synergistic effect were determined by spore germination and mycelium growth rate method. The results showed that pyridaben, fenpropathrin, clofentezine, flufenoxuron, spirodiclofen, chlorfenapyr and spiro-tetramat inhibited the spore germination and mycelium growth of A. hansfordii at different concentrations, and the inhibition was shown to different extents. Pyridaben, chlorfenapyr and spirodiclofen had a synergistic effect with A. hansfordii against two-spotted spider mite. Pyridaben, chlorfenapyr and spirodiclofen had an inhibiting action on conidial germination of A. hansfordii, and their inhibiting efficiencies were 27. 67%, 27. 83% and 29. 22% , respectively, at higher concentration. They had an inhibiting action on mycelial growth of A. hansfordii , and their inhibiting efficiencies were 20%, 18% and 18%, respectively. Their inhibition on some isolates was significantly reduced, and they had a better compatibility with A. hansfordii. The results of bioassays showed that it had obvious synergism against two-spotted spider mite, when A. hansfordii (1×106 spores/mL) was mixed with pyridaben (25 μ/mL), chlorfenapyr (0.83 μg/mL) and spirodiclofen (60 μg/mL) after 11 days. The LT50 of the three kinds of acaricides mixed with A. hansfordii (1×106 spores /mL) were 5. 38 d, 5.41 d and 5. 79 d, respectively, 4.19 d, 4.16 d and 3.78 d shorter, respectively, than that of A. hansfordii (1×106 spores /mL) used alone.