高效新型杀松材线虫剂的筛选及其林间防效

为筛选出新型的高效松材线虫Bursaphelenchus xylophilus防治药剂,采用浸渍法室内测定了氯氟氰虫酰胺、阿维菌素、甲维盐、灭多威、特丁硫磷、甲基异柳磷和吡虫啉7种药剂对松材线虫的毒杀作用和对其繁殖能力的影响,采用高效液相色谱仪测定氯氟氰虫酰胺在马尾松体内的输导分布,并在林间开展树干注射氯氟氰虫酰胺抗松材线虫病试验。结果表明,7种药剂中氯氟氰虫酰胺对松材线虫的毒力最强,LC_(50)为0.019 mg/L,阿维菌素和甲维盐次之,LC_(50)分别为0.0213 mg/L和0.0214 mg/L。氯氟氰虫酰胺树干注射3个月内能迅速从马尾松基部传导至树梢顶部,树干边材东、南面的药剂含量显著高于西、北面,且树干不同高度的氯氟氰虫酰胺含量均高于其LC50;氯氟氰虫酰胺制剂在林间注干后,对人工接种病原松材线虫松树的防治效果为73.33%,自然感染松材线虫病松树的死亡率降至2.00%,而对照试验中人工接种松材线虫松树和自然感染松材线虫病松树的死亡率分别为93.33%和19.67%。表明氯氟氰虫酰胺制剂能有效预防松树个体的松材线虫病发生与为害,可以推广使用。

Screening and prevention effect of new and effective pesticides against pine wilt nematode Bursaphelenchus xylophilus

In order to screen out efficient new pesticides against pine wilt nematode Bursaphelenchus xylophilus, the toxicity and reproductive effect of seven pesticides, cyhalodiamide, abamectin, emamectin benzoate, methomyl, terbufos, isofenphosmethyl and imidacloprid, on B. xylophilus were measured with impregnation method. After the injection of cyhalodiamide, high performance liquid chromatography was used to examine its distribution with tree heights. The results showed that the LC₅₀ of cyhalodiamide was 0.019 mg/L, which could poison and inhibit the B. xylophilus population, while the LC₅₀ values of abamectin and emamectin benzoate were 0.0213 mg/L and 0.0214 mg/L, respectively. The medicament could be quickly transported from the base to top of the pine after cyhalodiamide injection in three months. The content of cyhalodiamide in east and south sides of the trunk was significantly higher than that in the west and north sides. The content of cyhalodiamide in different heights of tree trunks was higher than LC₅₀. The prevention effect of cyhalodiamide reached 73.33% in the tested pine trees inoculated with B. xylophilus, and the pine mortality rate decreased to 2.0% in the tested pines while it was 19.67% in the control pines naturally infected with pathogens, and 93.33% in the control pines inoculated with B. xylophilus. It indicated that cyhalodiamide could prevent pine wilt disease effectively.