新型杀蜂螨烟剂蜂乐1号的研究

蜂乐1号烟剂是一种最近研制成功的新型杀蜂螨药剂,其有效成分为溴螨酯.经室内外试验结果,对蜂螨有较强杀伤力,对蜜蜂十分安全.烟剂中的溴螨醋对雅氏大蜂螨的LC_(50)为0.26克/米~3,LC_(95)为2.92克/米~3 对蜜蜂则分别为71.45克/米~3和218.70克/米~3,二者分别相差274.8倍和74.9倍.一平箱蜂群一次用含0.45克有效成分的药,对蜂体上大蜂螨的防除效果平均93%以上.对蜂群每隔5天施药一次,经3次施药后蜂群状况正常.在施药3次后对所取蜜样进行检测,其中溴螨酯的残留量远远低于联合国粮农组织所规定的参考限量.该烟剂适于在蜂箱外施药,比目前国内一般的开箱施药方法提高工效15倍以上,更适用于许多过去不便用药的场合.     

不同熏蒸剂杀灭无土栽培基质中尖孢镰刀菌的效果评价

通过人工接种尖孢镰刀菌于无土栽培基质,采用稀释涂抹平板法测定基质中尖孢镰刀菌的数量变化,研究威百亩、棉隆、氰氨化钙、甲醛、1,3-二氯丙烯、二甲基二硫和甲基碘7种熏蒸剂不同浓度处理及作用时间对无土栽培基质中尖孢镰刀菌的作用效果。结果表明:7种熏蒸剂均可以显著降低基质中尖孢镰刀菌的数量。其中,120mg·L-142%威百亩和300mg·L-198%棉隆熏蒸5d对尖孢镰刀菌的灭杀率达100.00%;40%甲醛稀释50倍、800mg·L-1氰氨化钙、400mg·L-1二甲基二硫、150mg·L-11,3-二氯丙烯和300mg·L-1甲基碘熏蒸8d对尖孢镰刀菌的灭杀率分别达99.07%、98.71%、96.57%、94.86%和85.00%。由此得出,威百亩和棉隆对无土栽培基质中尖孢镰刀菌的灭杀效果最显著,且熏蒸时间短,其次为甲醛与氰氨化钙。     

两种熏蒸剂对土传病害的防控效果及黄瓜产量的影响

在北京顺义黄瓜大棚中采用注射法施用二甲基二硫、混土法施用棉隆,对土壤进行熏蒸处理,施药后土壤表面覆盖完全不透膜,比较二甲基二硫与棉隆对黄瓜主要土传病害的防治情况及对黄瓜生长和产量的影响。结果表明,两种熏蒸剂对黄瓜根结线虫(Meloidogynespp.)、疫霉菌(Phytophthora spp.)和镰刀菌(Fusariumspp.)均有较好的防效,二甲基二硫40g·m~()-2)处理时对3种病原物的防效分别为84.29%、75.99%、79.94%,棉隆30.0g·m~()-2)处理的防效分别为80.30%、92.36%、92.27%,而且二甲基二硫、棉隆处理与空白对照相比,黄瓜净收入分别增加66%~85%和65%~71%。     

3种有机磷杀虫剂对烟草粉螟幼虫的室内熏杀效果

目前我国农户烟仓害虫的防治多采用有机磷杀虫剂进行熏杀处理,但因施药剂量随意性较大而影响卷烟原料的品质,寻找科学合理的熏杀剂量意义重大。采用滤纸载药密闭熏蒸法,研究了敌敌畏、毒死蜱和辛硫磷3种常规有机磷杀虫剂熏蒸浓度分别为3、6和9 g/m3时对烟草粉螟3龄幼虫的室内熏杀效果。结果表明：敌敌畏熏杀效果最好,辛硫磷次之,毒死蜱熏杀效果最差。敌敌畏3 g/m3浓度熏蒸3 d,试虫的校正死亡率可达89.9％;辛硫磷6 g/m3浓度熏蒸5 d,试虫的校正死亡率可达88.3％;毒死蜱6 g/m3浓度熏蒸5 d,试虫的校正死亡率为76.3％。目前在我国农户烟仓害虫防治方面,敌敌畏仍不失为一种理想的熏杀药剂。     

氰在土壤中的吸附与转化

氰(C2N2)是一种具有替代溴甲烷潜力的新熏蒸剂,明确C2N2在土壤中的吸附与转化行为对C2N2的安全应用具有重要的意义.利用静态法研究了C2N2在土壤中的吸附与转化过程,土壤对C2N2的吸附速率与土壤的理化性质有关,受环境温度、土壤含水量和土壤生物的影响较少,与熏蒸浓度无关.采用气相色谱(GC)和流动注射分析仪(FIA)测定了土壤对C2N2的吸附率和C2N2在土壤中的可能转化产物.结果表明,土壤对C2N2的吸附能力很强,熏蒸2h吸附率在75％以上,熏蒸24 h吸附率在98％以上,并可快速转化为HCN、NH4+和NO3-.其中,大约20％的C2N2转化为NH4+和NO3-,13％的C2N2转化为HCN.熏蒸48 h未检测到NO2-.HCN在土壤中不稳定,可进一步转化为其他含氮化合物.     

Fumigant and contact toxicity of Myrtaceae plant essential oils and blends of their constituents against adults of German cockroach (Blattella germanica) and their acetylcholinesterase inhibitory activity

Fumigant and contact toxicities of 11 Myrtaceae plant essential oils and their constituents against adult male and female Blattella germanica were evaluated. Of 11 Myrtaceae plant essential oils, Eucalyptus polybractea, Eucalyptussmithii, Eucalyptusradiata, Eucalyptusdives, Eucalyptusglobulus, and Melaleuca uncinata, showed 100% fumigant toxicity against adult male German cockroaches at a concentration of 7.5 mg/liter air concentration. In contact toxicity tests, E. polybractea, E. smithii, E. radiata, E. dives, E. globulus, Melaleucadissitiflora, and M. uncinata produced strong insecticidal activity against adult male and female German cockroaches. Of the essential oil constituents, terpinolene, α-terpinene, and terpinen-4-ol demonstrated strong fumigant toxicity against adult male and female B. germanica. Eugenol, isoeugenol, methyl eugenol, and terpinen-4-ol showed strong contact toxicity against adult male B. germanica. The toxicity of the constituent blends identified from M. dissitiflora essential oils indicated that terpinen-4-ol were major contributor to the fumigant activity or contact toxicity of the artificial blend. Only isoeugenol exhibited inhibition activity against male acetylcholinesterase. IC₅₀ values of isoeugenol were 0.22 mg/mL against male acetylcholinesterase.     

Fumigant and repellent activities of essential oil from <Emphasis Type="Italic">Coriandrum sativum</Emphasis> (L.) (Apiaceae) against red flour beetle <Emphasis Type="Italic">Tribolium castaneum</Emphasis> (Herbst) (Coleoptera: Tenebrionidae)

The biological activity of essential oil extracted from coriander, Coriandrum sativum L. (Apiaceae) against eggs, larvae and adults of Tribolium castaneum (Herbst) was investigated in a series of laboratory experiments. Bioassays conducted in air-tight glass chambers showed vapour toxicity and strong repellency on filter paper arena test towards all the stages used. Responses varied significantly (P < 0.001) within insect stages, dosages and exposures. At 12.0 μg/ml dosage, mortality of adults reached 95%, but for 12-, 14- and 16-days larvae, mortalities were 65, 74 and 82%, respectively. On the developmental inhibition, individuals fumigated at the larval stage confirmed that the percentage of larvae reaching to pupal stage and pupae to adult stage, decreased significantly (P < 0.001) with increasing dosage concentration. The oil fumigation yielded 100% mortality for T. castaneum larvae, pupae and adults at 0.08 μg/ml dosage. The oil had fumigant activity against eggs and the toxicity progressively increased with increased exposure times and concentrations. One hundred per cent T. castaneum egg mortalities were obtained with oil fumigation at 20 μg/ml and 96 h exposure period. C. sativum oil also showed highly repellent activity to the adults of T. castaneum, with overall repellency was 90% and at a dosage of 12 μg/ml repellency was 100% in a filter-paper arena test.     

Fumigant toxicity of Carum copticum and Vitex pseudo-negundo essential oils against eggs, larvae and adults of Callosobruchus maculatus

Fumigant activity of essential oil vapors distilled from Carum copticum C. B. Clarke and Vitex pseudo-negundo Hand I. MZT. was tested against eggs, larvae and adults of Callosobruchus maculatus (F.). Fumigant toxicity was assessed at 27 ± 1°C and 60 ± 5% RH, in dark condition. The influence of different concentrations of the essential oil vapors on egg hatchability, larval and adult mortality was significant. Data probit analysis showed that lethal concentration of the essential oil to kill 50% of the population (LC₅₀) for egg, larvae and adult were found to be 1.01, 2.50 and 0.90 μl/l air of C. copticum oil, followed by 2.20, 8.42 and 9.39 μl/l air essential oil of V. pseudo-negundo, respectively. Between these essential oils, C. copticum was almost more toxic than V. pseudo-negundo on all growth stages of C. maculatus. The present study suggests that essential oils from these medicinal plants may be potential grain protectants as botanical alternative fumigants and could be used in the management of various life stages of C. maculatus.     

几种熏蒸剂及杀细菌剂对樱桃根癌病菌的室内毒力试验

采用密闭熏蒸法及抑菌圈法测定了氯化苦、棉隆、威百亩、1,3-二氯丙烯及11种杀细菌剂对樱桃根癌病菌的毒力。结果表明:威百亩、棉隆、氯化苦对樱桃根癌病菌的EC50为1.5881、2.7902、5.0475μg/mL,分别为1,3-二氯丙烯的519.60、295.74、163.48倍;杀细菌剂对樱桃根癌病菌的抑菌效果最为明显的是1 000亿活芽孢/g枯草芽孢杆菌可湿性粉剂、72%农用硫酸链霉素可溶性粉剂、85%三氯异氰尿酸可溶性粉剂和46%氢氧化铜水分散粒剂,可应用于田间药效试验进一步验证。     

A·H植物杀螨剂的研究

筛选１３种植物的根、茎、叶、种子提取物，组成１４种不同的单方和复方，配制成喷雾和熏蒸剂型的杀螨剂。喷雾剂型复方植物杀螨剂，杀螨效果达到“杀螨剂一号”的９５．２％；熏蒸剂型复方植物杀螨剂，杀螨效果达到“螨扑”的９６．２％。Ａ·Ｈ植物杀螨剂，在蜂群繁殖期防治蜂螨效果达到８６％，在断子期达到９４％。