应用CPV林间防治越冬代马尾松毛虫试验

应用CPV林间进行越冬代马尾松毛虫防治试验,结果表明不同剂量CPV与1/100000的20%氰戊菊酯乳油复配能显著提高CPV的林间杀虫效果。林间以CPV2.4×106~1.5×105多角体/ml与1/100000的20%氰戊菊酯乳油复配防治越冬代马尾松毛虫为宜,13天幼虫死亡率可达85%以上。     

Quantitative structure—activity studies of insect growth regulators. XI. Stimulation and inhibition of N-acetylglucosamine incorporation in a cultured integument system by substituted N-tert-butyl-N,N′-dibenzoylhydrazines

The ability to stimulate N-acetylglucosamine (GluNAc) incorporation in-vitro of a number of N-tert-butyl-N,N′-dibenzoylhydrazines having various substituents on both phenyl rings was measured in cultured integument excised from the rice stem borer (Chilo suppressalis Walker). The relationship between in-vitro and larvicidal potency was approximately linear. The substituent effects on variations in the potency were similar between in-vitro and larvicidal activities. An inhibitor of oxidative detoxication, piperonyl butoxide, had no synergistic effects on the in-vitro potency. The ability of some dibenzoylhydrazines to inhibit GluNAc incorporation at exposure periods longer than the optimum for stimulation was also measured in a similar cultured integument system. The relationship between the inhibitory and stimulatory potency indices was linear, indicating that the larvicidal activity of dibenzoylhydrazines is closely related to its ability to stimulate as well as to inhibit GluNAc incorporation into the larval cuticle.     

Fipronil resistance mechanisms in the rice stem borer, Chilo suppressalis Walker

Fipronil resistance mechanisms were studied between the laboratory susceptible strain and the selective field population of rice stem borer, Chilo suppressalis Walker in the laboratory. The borer population was collected from Wenzhou county, Zhejiang province. After five generations of selection, fipronil resistance ratio was 45.3-fold compared to the susceptible strain. Synergism experiments showed that the synergistic ratios of PBO, TPP and DEF on fipronil in susceptible and resistant strains of C. suppressalis were 7.55-, 1.93- and 2.91-fold, respectively, and DEM showed no obvious synergistic action on fipronil. Activities of carboxylesterase and microsomal-O-demethylase in the resistant strain were 1.89- and 1.36-fold higher that in susceptible strain, and no significant difference of glutathione-S-transferase activity was found between the resistant and susceptible strains. The K_m and V_max experiments also demonstrated that fipronil resistance of C. suppressalis was closely relative to the enhanced activities of carboxylesterase and microsomal-O-demethylase. Moreover, cross-resistance between fipronil and other conventional insecticides and the multiple resistant properties of the original Wenzhou’s population were also discussed.     

三化螟卵块寄生蜂-螟卵啮小蜂研究概况

螟卵啮小蜂Tetrastichus schoenobii Ferriere是一种寄生三化螟Trypoyyza incertulas(Walker)卵块的重要天敌。本文总结了其生物学、形态学、生态学以及应用研究等方面的研究概况,并对其开发利用提出新的思路。     

用随机发育模型预测马尾松毛虫的发生期

用马尾松毛虫各龄虫口密度的定期调查资料和积温资料,拟合Logistic随机发育模型,结果表明,该模型能精确地描述马尾松毛虫第1代1～6龄幼虫的发育进程。对各龄虫口的时间分布,模型预测值和观察值的吻合程度达90%。对模型参数进行比较表明,除了温度(积温)以外,还有另外一些因素影响着马尾松毛虫的发育进程。     

增效剂对马尾松毛虫羧酸酯酶的抑制作用

对江西省十余个县（市）马尾松毛虫（ＤｅｎｄｒｏｌｉｍｕｓｐｕｎｃｔａｔｕｓＷａｌｋｅｒ）的测定表明，马尾松毛虫各种群对拟除虫菊酯的耐药力与羧酸酯酶活性有关；对溴氰菊酯、氰戊菊酯和氯氰菊酯耐药力强的种群，其羧酸酯酶活性亦强；应用五种增效剂对马尾松毛虫羧酸酯酶进行处理，ＳＶ＿１和ＴＰＰ表现出明显的抑制作用，且随ＳＶ＿１和ＴＰＰ剂量的增加，羧酸酯酶活性逐步降低；用相同剂量的ＳＶ＿１和ＴＰＰ处理马尾松毛虫后，羧酸酯酶均随时间表现出相似的变化规律。     

竹织叶野螟Algedonia coclesalis Walker越冬幼虫的真菌病

粉质拟青霉Paecilomyces farinosus (Dicks.ex.Fr.)Brown et Smith是竹织叶野螟越冬幼虫的重要病原菌,林间自然发病率为23.08％～42.84％。用5.5×10~6/ml孢子悬液感染越冬幼虫,死亡率达91.7％。在24～26℃下,病程约10～14d。林间罹病虫尸上,可见粉质拟青霉被寄生黑孢壳Melanospora parasitica Tulasne寄生。本文还从病原菌的生理性质及侵染环境的角度,讨论了疾病的流行条件和病原菌利用的前景。     

白僵菌防治马尾松毛虫试验

在越冬的马尾松毛虫幼虫上树取食期(4月),喷施含孢量110亿/克,活孢率82.9%,施菌量为37.5kg/hm2的白僵菌粉剂后,感染白僵菌的马尾松毛虫,每平方米11.3头,蛹期死亡率42.0%,第二年蛹期死亡率26.1%。在马尾松毛虫下树越冬期(11月),喷施含孢量48亿/克,活孢率76%,施菌量为30kg/hm2的白僵菌粉剂后,越冬期间,马尾松毛虫死亡率32.2%;第二年白僵菌致死率63.3%;第三年白僵菌致死率13.3%。     

马尾松毛虫防治关键期与防治历

本文分析了马尾松毛虫（Dendrolimus punctatus Walker）防治关键期,发现马尾松毛虫种群密度快速增长期在增殖期末期,在增殖期末期开展有效的防治,可以预防马尾松毛虫暴发成灾,并依据这一原理编制了马尾松毛虫防治月历和防治周期历。