不同波长黑光灯对椰子木蛾的诱集效果

为评估不同波长黑光灯对椰子木蛾的诱集效果,在海南省万宁市兴隆镇设置试验点,利用8种不同波长的黑光灯进行诱集试验。结果显示:椰子木蛾对365 nm和368 nm的波长敏感,诱虫总量显著多于其它波长的黑光灯;365 nm黑光灯诱捕椰子木蛾雄虫最多,368 nm黑光灯诱捕椰子木蛾雌虫最多,均显著大于其它黑光灯诱集到的雌雄虫数量。23∶00-2∶00为最适宜诱捕椰子木蛾时段。为利用黑光灯监测椰子木蛾提供了基础依据。     

周氏啮小蜂(海南种群)对椰子织蛾的寄生功能反应

【目的】周氏啮小蜂(海南种群)是寄生椰子织蛾蛹期的本土天敌。研究周氏啮小蜂(海南种群)对椰子织蛾的功能反应,能为该蜂室内扩繁和室外控害利用提供基础。【方法】在室内观察周氏啮小蜂(海南种群)寄生行为基础上,研究了营养(10%蜂蜜)、寄主蛹(初、中、晚)期对周氏啮小蜂(海南种群)寄生功能反应的影响。【结果】镜下观察1头周氏啮小蜂(海南种群)可寄生多头椰子织蛾蛹,寄生量随寄主密度的增大而增加,但当寄主密度达到一定程度后,其增长率随寄主密度的增大逐渐减缓,属于HollingⅡ功能反应。在无营养条件下,周氏啮小蜂(海南种群)对椰子织蛾初、中、晚期蛹的理论最大寄生量分别为1.5、1.4、1.2头·d~(-1);在10%蜂蜜饲喂条件下,周氏啮小蜂(海南种群)对椰子织蛾初、中、晚期蛹的理论最大寄生量分别为1.8、1.7、1.3头·d~(-1)。【结论】HollingⅡ型拟合结果表明,椰子织蛾初期蛹是周氏啮小蜂(海南种群)寄生的最佳时期,补充营养能够提高椰子织蛾的寄生力。     

苏云金芽胞杆菌的鉴定及对椰子织蛾的致死作用

【背景】利用采集到的样品分离出苏云金芽胞杆菌菌株,针对椰子织蛾幼虫进行室内生物活性测定,以期获得对椰子织蛾幼虫具有高毒力菌株,并为椰子织蛾的生物防控提供理论和技术依据,同时为转Bt基因作物提供新的基因资源。【方法】在海南岛椰子织蛾潜在分布区采集样品,利用温度法筛选苏云金芽胞杆菌并进行形态学和分子生物学鉴定,采用浸叶法进行Bt菌株对椰子织蛾幼虫的生物活性测定。【结果】海南省保亭县土壤样品中筛选出8株菌株,电子显微镜下观察到该批菌株含有菱形、球形、方形晶体;通过分子生物学鉴定明确了6株菌株含有cry基因,2株没有鉴定出cry基因;利用相同浓度菌悬液对椰子织蛾幼虫进行了生物活性测定,结果表明,50μg·m L-1的BAT10菌株杀虫晶体蛋白对椰子织蛾幼虫的致死率达100%,同样浓度的29-15-4与BAT20菌株杀虫晶体蛋白对椰子织蛾幼虫的致死率超过80%,其余5株Bt的杀虫晶体蛋白致死率较低,致死率小于50%。【结论与意义】本试验筛选出1株高毒力菌株和2株效果较好的Bt菌株,可应用于椰子织蛾的生物防控。     

Production protocol for and storage efficacy of an anthocorid predator Cardiastethus exiguus Poppius

Cardiastethus exiguus Poppius is an indigenous anthocorid predator of eggs and neonates of the notorious pest,coconut black-headed caterpillar Opisina arenosella Walker in India.At the National Bureau of Agriculturally Important Insects(Indian Council of Agricultural Research),Bangalore,India,a simple mass production protocol was developed for multiplying C.exiguus using UV-irradiated eggs of alternate laboratory host Corcyra cephalonica Stainton.Field evaluation of the predator in the states of Kerala and Karnataka indicated that this predator could bring about a significant reduction in the pest population.Subsequently,the need was felt to investigate the storage efficacy of the eggs and adults of C.exiguus so that sufficient numbers could be accumulated and transportation of the predator could be planned for field releases.Low temperature storage studies indicated that C.exiguus eggs can be safely stored for up to 5 days at 10℃ and 10 days at 15℃ and incubation period could be staggered for up to 10 and 13 days,respectively.The longevity of the C.exiguus adults was significantly reduced due to low temperature storage.However,for adult females,a storage temperature of 15℃ for 15 days could be recommended as they could live for a more than a month after removal from storage and their progeny production was comparable to that of the control adults.     

Aflatoxin production by Aspergillus flavus isolates pathogenic to coconut insect pests

Aspergillus flavus isolated from naturally infected leaf-eating caterpillar (Opisina arenosella W.), lace bug (Stephanitis typica D.) and plant hopper (Proutista moesta Westwood), insect pests of the coconut palm, were tested for aflatoxin (AT) production by employing various media formulations. These A. flavus isolates were earlier found to be entomopathogenic in laboratory bioassays. A laboratory contaminant and four standard aflatoxigenic A. flavus isolates were also included in this study as reference strains. All A. flavus isolates were tested on seven AT detection media: coconut extract agar, coconut extract-sodium desoxycholate agar, coconut extract-ascorbic acid agar, coconut extract-Czapek Dox agar, coconut extract-milk powder agar, 10% commercial coconut milk powder agar (CCMPA) and 20% CCMPA. Only two isolates of A. flavus, originally isolated from O. arenosella and P. moesta, produced ATs. AT production was detected within 48 h of incubation and was detected continually up to 1 month. These AT-producing A. flavus isolates also produced bright yellow pigmentation in the medium. Of all the seven media used for AT detection, CCMPA (10%) was found to be the best one, followed by 20% CCMPA, for direct and rapid AT detection. AT production was not necessary for pathogenicity in the insects. This revised version was published online in July 2006 with corrections to the Cover Date.     

Potential for lab rearing of <Emphasis Type="Italic">Apanteles taragamae</Emphasis>, the larval endoparasitoid of coconut pest <Emphasis Type="Italic">Opisina arenosella</Emphasis>, on the rice moth <Emphasis Type="Italic">Corcyra cephalonica</Emphasis>

A lab rearing technique was standardised for Apanteles taragamae Viereck (Hymenoptera: Braconidae), the early larval parasitoid of the coconut leaf-eating caterpillar, Opisina arenosella Walker on the alternate host Corcyra cephalonica Stainton (Lepidoptera: Pyralidae). The parasitoid took 23.3 ± 3.2 days to complete the egg to adult period. Adult longevity for males and females was 15.3 ± 4.6 and 13.8 ± 4.6 days respectively. Fecundity was 14.8 ± 4.3 eggs per female. The percentage parasitism was 60.6 ± 5.7 on the alternative host C. cephalonica and 64.6 ± 5.5 on the natural host O. arenosella. Eight- to ten-day-old caterpillars were the ideal stage of C. cephalonica for rearing A. taragamae. The results indicated the amenability of rearing A. taragamae on C. cephalonica in the laboratory.     

营养对不同地理种群周氏啮小蜂生物学特性的影响

【目的】研究补充营养对周氏啮小蜂海南本土地理种群和北京地理种群的生物学参数是否有差异。【方法】设置不同的营养(10%蜂蜜、10%蔗糖、10%葡萄糖、水、空白)分别饲喂周氏啮小蜂,统计2个地理种群的寄生率、羽化率、出蜂量、寿命。【结果】2个地理种群的周氏啮小蜂羽化后不久即可进行交配,补充10%蜂蜜、10%蔗糖、10%葡萄糖能显著提高2个地理种群的寄生率、羽化率、出蜂量、雌雄蜂寿命,补充不同的营养对两个地理种群的雌雄比、发育历期的影响差异不显著;饲喂10%蜂蜜的海南地理种群寄生率最高(84.60%),饲喂10%葡萄糖的海南地理种群羽化率最高(97.47%),饲喂10%葡萄糖的海南地理种群出蜂量最高(60.03头),饲喂10%葡萄糖的海南地理种群雌、雄蜂的寿命均为最高,分别为9.13和8.53d。营养和地理种群的交互作用对周氏啮小蜂雄蜂的寄生率、羽化率、出蜂量、雌雄比、雌雄蜂寿命具有显著影响,而对周氏啮小蜂的发育历期无显著影响。【结论】补充营养可不同程度促进周氏啮小蜂生殖力、寿命及寄生率,对寄生蜂繁育和利用其进行生物防治具有一定的意义。     

椰心叶甲、椰子织蛾肠道菌群多样性分析

[目的] 椰心叶甲、椰子织蛾同属棕榈科食叶性入侵害虫,两者同时取食棕榈科植物却无明显竞争作用,本文通过分子生物学手段对两者的肠道菌群组成、肠道代谢通路进行比对,以此探讨两者食性之间相关性。[方法] 以16S rRNA菌群分析等预测手段对两者肠道微生物群落、代谢通路等进行差异分析。[结果] 椰心叶甲体内变形菌门群落丰度显著高于椰子织蛾,椰子织蛾体内蓝菌门、放线菌门、酸杆菌门、疣微菌门等菌群丰度显著高于椰心叶甲;椰心叶甲体内膦酸酯和亚膦酸盐代谢、N-聚糖合成等肠道代谢通路显著强于椰子织蛾,而椰子织蛾肠道中酮体的合成和降解、维生素B6代谢、核黄素代谢、黄酮和黄酮醇生物合成等代谢通路显著强于椰心叶甲。[结论] 椰子织蛾体内相对较高的酸杆菌门丰度可能导致了其偏好取食纤维素高的椰子老叶,而椰心叶甲则相反。同时,椰子织蛾肠道内显著较高的维生素B含量在其族群发展过程中起到了主要作用。两者细菌丰度以及代谢通路强度的差异可能影响了两者的食性。     

椰子木蛾的产卵节律及其对寄主植物的产卵选择性

【背景】椰子木蛾是近年来新入侵我国棕榈科植物的害虫,研究其产卵习性可为监测和防治该虫提供参考。【方法】在室内条件下,观察、记录了椰子木蛾雌成虫的产卵节律及其对不同寄主植物的产卵选择性。【结果】椰子木蛾最高日产卵量可达34.4粒·头-1,且主要集中在羽化后4 d内产卵,占总产卵量的54.1%;产卵活动主要发生在夜间23:00到次日8:00;在椰子、蒲葵、大王棕、槟榔和散尾葵等寄主植物上的产卵量无显著差异,为89.3~147.7粒·头-1,但产卵位置存在差别。【结论与意义】椰子木蛾雌成虫具有较强的繁殖能力和产卵节律性,且在不同寄主植物上的产卵量一致。     

新入侵害虫椰子织蛾的3种本地寄生蜂

【目的】椰子织蛾是近期入侵中国的棕榈植物重要害虫,研究其天敌寄生蜂,能为椰子织蛾的进一步防控提供科学依据。【方法】在海南岛收集鉴定了椰子织蛾天敌寄生蜂,观察记录寄生蜂发育历期、雌雄性比、成虫寿命等基础生物学特性。【结果】经形态及分子鉴定,收集到的椰子织蛾寄生蜂有幼虫期寄生蜂麦蛾柔茧蜂、蛹期寄生蜂金刚钻大腿小蜂和周氏啮小蜂。在温度(26±2)℃、湿度(75±10)%RH、以椰子织蛾为寄主条件下,麦蛾柔茧蜂、金刚钻大腿小蜂和周氏啮小蜂发育历期分别为11.8、19.6和20.6 d;每头寄主的出蜂量分别为10.1、1.0和81.5头;雌蜂占比分别为26.6%、40.6%和89.8%;每种寄生蜂雌蜂寿命均长于雄蜂。【结论】保护和利用椰子织蛾的3种本地寄生蜂,将有助于椰子织蛾的防控。