【作者】 Ko Ko；

【导师】 侯茂林；

【作者基本信息】 中国农业科学院 ， 农业昆虫与害虫防治， 2014， 博士

【摘要】 赤眼蜂是一种应用最广泛的寄生蜂,它可以控制很多种危害严重的害虫。为了针对湄公河次区域构建以赤眼蜂为主的水稻害虫综合治理技术,我们针对湄公河次区域采集的9个品系进行了室内筛选试验,在田间针对3个性状表现比较好的品系进行了进一步的效果测定。在室内,测定了四种常用的防治稻飞虱的农药对螟黄赤眼蜂(崔家品系)成虫和若虫的毒性,以确定适合的配套杀虫剂品系和施用时间。另外,在广西省兴安县界首镇新五里村示范了赤眼蜂为主的水稻害虫综合治理技术。1适合湄公河次区域二化螟防治的赤眼蜂品系的筛选赤眼蜂种往往具有寄主专一性,同一个种的不同品系也有不同的表现。通过室内实验和田间试验,比较了湄公河次区域稻区收集的赤眼蜂对二化螟卵的寄生力和其它发育指标,以期筛选出适合于田间大规模释放的赤眼蜂品系。室内实验表明,二化螟卵龄对赤眼蜂的寄生率和出蜂率有显著影响,所有赤眼蜂品系在0-24h的卵上的平均寄生率(34.0%)显著高于在24-48(24.7%)和48-72h(20.0%)的卵上的相应指标,在0-24h的卵上的出蜂率(84.0%)也显著高于在24-48和48-72h卵上的出蜂率,然而0-24h二化螟卵上的赤眼蜂若虫发育历期显著延长。螟黄赤眼蜂崔家品系的寄生率最高(49.7%)。田间试验中,采用3个赤眼蜂品系、设置了50000、100000和200000头蜂/公顷的放蜂量和不放蜂对照,不同处理中设置二化螟哨兵卵块。所有处理的赤眼蜂寄生率均较低(低于13.1%),但是处理间的赤眼蜂寄生率差异显著。螟黄赤眼蜂崔家品系在高和中等放蜂量时,寄生率最高,分别为13.1%和11.4%。因此,田间防治二化螟的最佳赤眼蜂品系为螟黄赤眼蜂崔家品系,放蜂量以100000头蜂/公顷较为经济有效。2.防治稻飞虱的杀虫剂对赤眼蜂成虫和若虫的毒性采用国际生物防治组织(IOBC)的测试方法,室内测试了防治稻飞虱的杀虫剂,吡蚜酮(pymetrozine)、噻虫嗪(thiamethoxam)、噻嗪酮(buprofezin)和烯啶虫胺(nitenpyram),对螟黄赤眼蜂崔家品系的成虫和若虫的毒性。在药膜残留实验中,所有4中杀虫剂均导致90%以上的赤眼蜂成虫死亡,按照IOBC的划分标准,它们对赤眼蜂成虫具有中度害性。杀虫剂持效毒性测试结果表明,烯啶虫胺仅有短期毒性(残效期小于5d),其它三种杀虫剂持效期略长(残效期5-15d)。另外,采用二化螟卵作为寄主,测定了这些杀虫剂对赤眼蜂卵期、若虫期和预蛹期的影响。当赤眼蜂处于这三个发育期而接受杀虫剂处理时,所有4种杀虫剂都降低了寄主卵的寄生率。但是,烯啶虫胺和吡蚜酮用于赤眼蜂卵期、噻嗪酮和烯啶虫胺用于赤眼蜂若虫期、噻嗪酮和噻虫嗪用于赤眼蜂预蛹期时,寄主卵的寄生率相对对照下降幅度小于30%,按照IOBC的划分标准,这些杀虫剂在相应的赤眼蜂育阶段施用被划分为无害级。同样,出蜂率也受到杀虫剂的显著抑制。但是只有噻虫嗪用于若虫期和噻嗪酮用于预蛹期时,出蜂率相对对照下降了30%以上,按照IOBC的标准,这两种杀虫剂在相应的赤眼蜂发育阶段施用被划分为危害级。赤眼蜂幼期接受这4种杀虫剂处理对其性比和若虫发育历期无显著影响。本文结果对于以赤眼蜂大规模释放为主的水稻害虫综合治理具有重要意义,特别是当稻飞虱同时重发生时。3以赤眼蜂为主的水稻IPM的示范在广西省兴安县界首镇新五里村,在双季稻田测定了以赤眼蜂为主的水稻IPM田和常规防治田中天敌(蜘蛛、隐翅虫和绿盲蝽)和飞虱数量、二化螟和稻纵卷叶螟为害率、纹枯病危害程度,以评价水稻IPM的防控效果。水稻分蘖期后每周调查一次病虫害发生和为害数据,早稻和晚稻各调查5次。无论是早稻田还是晚稻田,IPM稻田的天敌数量总体上高于常规防治稻田,早稻田蜘蛛、隐翅虫和黑肩绿盲蝽分别高51.4%、37.0%和233.3%,晚稻田分别高19.7%、14.0%和86.7%。各调查日,IPM稻田和常规防治稻田中稻纵卷叶螟对早稻和晚稻的危害率均小于1.3%,低于防治指标。早稻和晚稻的IPM和常规防治田中,二化螟造成的平均枯心率低于0.9%,也低于防治指标。稻飞虱数量在早稻IPM区(513.9/100丛)高于常规防治区(167.2/100丛),但是在晚稻处理间没有差异(分别为93.5和141.6/100丛),均低于防治指标。无论早稻田还是晚稻田,IPM区赤眼蜂对稻纵卷叶螟卵的寄生率都显著高于常规防治区(早稻分别为23.0%和18.0%,晚稻分别为52.0%和7.0%)。在早稻田,IPM区用药量比常规防治区的低1.4倍；而在晚稻田,IPM区用药量比常规防治区低2.4倍。另外,IPM区早晚稻的产量均高于常规防治区,分别高155.5kg/ha和374.6kg/ha,但是处理间差异不显著。更多还原

【Abstract】 Trichogramma spp. are the most popular parasitoids being applied on a number of host crops. For the establishment of a Trichogramma-based rice IPM for the Greater Mekong Subregion, Trichogramma strains were collected from this region and a series of investigations were conducted to evaluate the performance of these strains. Nine Trichogramma strains were screened in the laboratory and three most promising strains were released in the paddy field with three different rates. Then, the toxicity of four commonly used planthopper-targetting insecticides were tested on adults and immature stages of T. chilonis (Cuijia),(Tc-Cuijia) in the laboratory. Moreover, Trichogramma release-based rice IPM was demonstrated in XinwuliVillage, JieshouTown, Xing’an County, Guangxi Zhuang Autonomous Region in2013.1. Evaluation for potential Trichogramma strains for control of the striped stem borer in the Greater Mekong SubregionTrichogramma species differ significantly in host specificity and performance of different strains also varies. Trichogramma collected from paddy fields in the Greater Mekong Subregions were evaluated for their performance on eggs of the striped stem borer (SSB), Chilo suppressalis Walker, in both laboratory and field tests to determine potential Trichogramma strains that can be employed in inundative release in an IPM program. In the laboratory tests, all strains showed higher parasitism rates on0-24h eggs (34.0%)than on the two older age groups (24.7%for24-48h and20.0%for48-72h), wasp emergence rate was also higher from parasitized0-24h SSB eggs (84.0%), while Trichogramma immature duration was significantly prolonged on0-24h SSB eggs. Parasitism rate differed among Trichogramma strains, T. chilonis Cuijia showing significantly higher parasitism rate (49.7%) than any other strains. In the field tests, parasitisms of sentinel SSB eggs by Trichogramma strains released at50,000,100,000, and200,000wasps per ha were low (below13.1%), with differences between strains being marginally significant. The highest parasitism was achieved by T. chilonis Cuijia strain at the high and medium release rates (13.1%and11.4%, respectively). Hence, it can be concluded that T. chilonis Cuijia strain released at100,000wasps per ha might be a cost-effective potential for field releases targeting the striped stem borer.2. Toxicity of insecticides targeting rice planthoppers to adult and immature stages of Trichogramma chilonisPlanthoppers-targeting insecticides, pymetrozine, thiamethoxam, buprofezin and nitenpyram, were tested under laboratory conditions for toxicity to adults and immatures of Trichogramma chilonis Ishii, using standard tests described by IOBC. In the dry film residue test, the insecticides all resulted in more than90%mortalities in T. chilonis adults and were ranked as moderately harmful. Persistent toxicity test revealed that nitenpyram was short-lived (<5d) and the other three insecticides were of slightly persistent toxicity (5-15d) to the wasp adults. Effects of the insecticides on egg, larval and prepupal stages of T. chilonis were investigated with striped stem borer as host. At the three stages of T. chilonis (within the host egg), all the insecticides reduced parasitism rate, but nitenpyram and pymetrozine applied at egg stage, buprofezin and nitenpyram at larval stage, and buprofezin and thiamethoxam at prepupal stage of T. chilonis reduced parasitism by less than30%in comparison with the control, and were thus ranked as harmless. Although insecticide treatments to the three immature stages of T. chilonis all reduced wasp emergence from host eggs, only thiamethoxam applied at larval stage and buprofezin at prepupal stage resulted in more than30%reduction in emergence rate as compared with the control and were categorized as harmful. Immature duration and sex ratio of emerged wasps were largely not affected by the insecticide treatments to the wasp immature stages. The data are of significance for IPM program incorporating inundative release of T. chilonis for control of lepidopteran rice pests where there is heavy co-occurrence of planthoppers.3. Demonstration of Trichogramma-based rice IPM in fieldsTrichogramma release-based rice IPM was demonstrated in Xinwuli Village, Jieshou Town, Xing’an County, Guangxi Zhuang Autonomous Region in summer and autumn rice seasons in2013, by comparison of incidence of natural enemies and planthopper, damaged leaves, damaged tillers, occurrence of sheath blight and rice blast, and grain yieldbetween farmer’s conventional practices and the Trichogramma-based IPM.Field survey was conducted weekly to the IPM and conventional rice field in both summer and autumn season rice (5surveys for each). More natural enemies were found in IPM plot than in conventional plot in both the summer rice (by51.4%for spiders,37.0%for rove beetles and233.3%green plant bugs per100hills) and autumn season (by19.7%for spiders,14.0%for rove beetles and86.7%for green plant bugs per100hills).Percentages of damaged leaves by rice leaf roller were below EIL on all sampling dates in both IPM and conventional plots in both summer and autumn rice (less than1.3%).Average percentages of dead heart were less than0.9%for both IPM and conventional plots in both summer and autumn rice. Average population of planthoppers per100hills was higher in IPM plot (513.9) than in conventional plot (167.2) in the summer rice, while in the autumn rice, the population size was not different (93.5for IPM plot and141.6for conventional plot), planthopper population was generally below EIL. Parasitism of rice leaf roller eggs was significantly higher in IPM plot (23.0%) than in conventional fields (18.0%) in the summer rice and in IPM plot (52.0%) than in conventional plot (7.0%) in the autumn rice. In the summer rice,1.4times less pesticide application was used in IPM plot (2times) than in conventional plot (3.4times), while2.4times less pesticide application was used in IPM plot (1time) than in conventional plot (3.4times) in the autumn rice. Rice yield was155.5kg/ha more in IPM plot than in conventional plot in the summer rice and374.6kg/ha more in IPM plot than in conventional plot in the autumn rice, but not significantly different between the treatments.更多还原