稻纵卷叶螟卷叶有虫率与化蛹率关系的研究

探索利用稻纵卷叶螟 Cnaphalocrocis medinalis（Guenée）卷叶有虫率估测化蛹率的方法和途径。本文基于稻纵卷叶螟化蛹进度的田间调查数据,用化蛹率（y）和卷叶有虫率（x）分别拟合直线函数、一元二次函数、一元三次函数、对数函数、指数函数和幂函数6种不同模型。结果表明,以一元三次函数方法估计精度最高,误差最小,应用效果最好,并根据最优数学模型建立化蛹率（y）与卷叶有虫率（x）的关系速查表。生产中可以应用拟合的 最优数学模型对田间稻纵卷叶螟化蛹进度进行监测。     

稻纵卷叶螟根虫瘟霉的分离鉴定及其流行病研究

在广东省发现一种新的侵染稻纵卷叶螟幼虫的昆虫病原真菌,经鉴定该病原真菌为根虫瘟霉Zoophthora radicans,这是中国首次报道该菌侵染稻纵卷叶螟。在室内进行的温度和光周期对该菌生长的影响实验表明,该菌在15－25℃均可生长,最适生长温度为25℃;光周期对菌落生长影响不显著。根虫瘟霉主要侵染稻纵卷叶螟3－5龄幼虫,对3－5龄幼虫的侵染率分别为2.71%、24.32%和72.97%。在10－11月,根虫瘟霉可持续引发稻纵卷叶螟幼虫高强度流行病,侵染率高达95%。该菌以休眠孢子越冬,成为次年稻纵卷叶螟幼虫流行病的初侵染源。因此,根虫瘟霉是稻纵卷叶螟幼虫一种有效的自然控制因子。     

重庆市2代稻纵卷叶螟发生警报

《中国植保资讯网》　今年重庆市 1代稻纵卷叶螟迁入偏早 ,迁入虫量较大 ,田间虫量偏高。 5月中旬 ,渝东南部的秀山县稻纵卷叶螟大量迁入 ,其成虫量数倍于大发生年的虫量。 6月上旬秀山、涪陵的每 667m2 幼虫量为去年同期的 45 8～ 5 0倍 ,东南部、南部、东北部及中部卷叶率为 0 5 2 %～ 1 3 7% ,最高卷叶率达到了 63 5 %。据渝东南部及南部区县调查 ,目前 2代稻纵卷叶螟已进入或正进入盛蛾期。綦江县田间赶蛾 2 0 0 3年 6月 2 0日达到高峰 ,田间每 667m2 蛾量在 2 5 0 0～ 2 95 0 0头之间 ,平均 95 0 0头 ,是 2 0 0 2年同期蛾量的 3 1…     

云南稻纵卷叶螟的发生与种群消长特点

2009—2012年,对滇西、滇西南、滇南、滇东南、滇东和滇东北6个稻区的稻纵卷叶螟Cnaphalocrocis medinalis Guenée种群发生特点进行了研究,结果表明:(1)云南主要稻区均没有采集到稻纵卷叶螟的各越冬虫态,表明云南稻区的稻纵卷叶螟早期虫源主要来自境外;(2)灯下虫源始见期在4月中旬到7月中旬,不同稻区的虫源迁入期变化较大,相差近3个月。滇西沧源和滇东南富宁虫源始见期最早,在4月中旬—5月下旬,滇西南勐海灯下始见期最晚,为6月上旬—7月中旬;(3)滇西、滇西南、滇东北和滇南为稻纵卷叶螟轻发生区,主要在中晚稻上发生危害,田间卷叶率在30%以下,田间发生量少于300头/667m2。滇东和滇东南为中等和重发生区,田间卷叶率在30%以上,高的达80%以上,田间虫量最高可达7 000头/667m2;(4)云南稻纵卷叶螟田间种群发生高峰期主要集中在5月下旬至9月下旬。滇东南高峰期为6月下—7月中旬,正值水稻孕穗期到抽穗开花期,应做好田间监测与防治工作。     

药剂防治稻纵卷叶螟幼虫的田间效果

为了筛选替代甲胺磷防治稻纵卷叶螟Cnaphalocrocismedinalis幼虫的药剂 ,对毒死蜱及其混配剂、氟虫腈 (锐劲特 )及其混配剂等 1 0多种农药进行了防治试验。试验结果表明 ,3 5 %纵卷清 (毒死蜱与乙酰甲胺磷 )可湿性粉剂、3 5 %毒斯威乳油、毒死蜱与敌敌畏混配剂以及高剂量的氟虫腈及其混配剂3 6%雄斯等药剂防治稻纵卷叶螟中高龄幼虫都有较显著的防治效果。 3 5 %纵卷清 80g 667m2 、3 5 %毒斯威 80mL 667m2 等药剂已在生产中大面积应用。在纵卷叶螟发生量大、虫龄偏高情况下 ,应适当增加用药量。     

稻纵卷叶螟绒茧蜂对寄主的搜索行为

稻纵卷叶螟绒茧蜂是稻纵卷叶螟幼虫的重要天敌。以Y形嗅觉仪测定了稻纵卷叶螟2—3龄幼虫虫粪、4—5龄幼虫虫粪、健康水稻、稻纵卷叶螟幼虫为害后水稻在纵卷叶螟绒茧蜂对寄主的搜索过程中的作用。结果表明已交配的雌蜂显著趋向稻纵卷叶螟2—3龄幼虫虫粪和4—5龄幼虫虫粪,不趋向健康水稻、稻纵卷叶螟幼虫为害后的水稻。雄蜂、处女雌蜂不显著趋向健康水稻、稻纵卷叶螟幼虫为害后水稻、稻纵卷叶螟2—3龄幼虫虫粪、稻纵卷叶螟4—5龄幼虫虫粪。利用固相微萃取(SPME)及气相色谱/质谱(GC/MS)联用分析稻纵卷叶螟2—3龄幼虫虫粪的化学成分,并通过Y-形嗅觉仪测试已交配雌蜂对稻纵卷叶螟2—3龄幼虫虫粪化学成分标准品的嗅觉反应,结果表明已交配的雌蜂显著趋向1-十一烯和异缬草醛,稻纵卷叶螟幼虫虫粪中的1-十一烯和异缬草醛可能是稻纵卷叶螟绒茧蜂搜索寄主的利他素。     

稻纵卷叶螟人工饲料配方的优化研究

应用二次正交旋转组合设计对稻纵卷叶螟Cnaphalocrocis medinalis Guenée人工饲料的配方进行了优化,以化蛹率为目标函数建立了二次回归模型,结果表明稻叶粉、麦胚粉、玉米粉、干酪素、酵母对稻纵卷叶螟幼虫发育与化蛹率影响较大,大豆粉的影响不明显。通过统计寻优获得的优化配方为:每135 g人工饲料中,稻叶粉3 g、麦胚粉8 g、玉米粉4 g、干酪素4 g、酵母粉4 g。在温度27℃,相对湿度80%左右,光照L∶D=16∶8的条件下,使用该优化配方饲养稻纵卷叶螟,25.6%的供试初孵幼虫能完成幼虫发育并化蛹,幼虫期平均26.9 d,蛹重16²2mg。与以前的研究结果比较,化蛹率与蛹重均有显著提高,而幼虫历期略短。     

重庆市稻飞虱和稻纵卷叶螟发生态势

《中国植保资讯网》由于今年稻飞虱、稻纵卷叶螟迁入虫量大,6月份的多雨气候条件又有利于迁入虫源繁殖而不利于药剂防治,造成6月下旬稻田稻飞虱及稻纵卷螟残虫量大,渝东南部及南部地区虫量明显高于其它地区。白背飞虱百丛虫量:渝东南部的秀山县1 62 3 0头,为2 0 0 3年同期的3 1倍。稻纵卷叶螟亩残虫量:秀山县3 5 93 5头,为特大发生年1 986年的3 49倍。根据6月下旬田间残虫量并结合7月份天气预报等因素进行综合分析,预计白背飞虱、稻纵卷叶螟7月上、中旬主害代在东南部地区特大发生,低龄幼(若)虫发生期7月中旬。其余地区为中等至大发生。重…     

转cry1Ab/1Ac,cry1C,cry2A基因水稻对田间稻纵卷叶螟及其捕食类天敌的影响

在转Bt基因水稻商业化之前需要评价其对靶标害虫及其天敌的影响.本研究连续2年在3个地点调查了3种转Bt水稻材料和非转基因水稻田间稻纵卷叶螟为害情况,稻纵卷叶螟及其4种捕食类天敌的种群密度、相对丰富度和种群动态.结果表明,水稻材料对卷叶率和稻纵卷叶螟幼虫种群密度有显著影响.非转基因水稻田间卷叶率显著高于3种转Bt基因水稻田.在调查期间,不同地点3种非转基因水稻田间稻纵卷叶螟幼虫的种群密度以及它在植食类功能团内的相对丰富度均显著高于3种转Bt基因水稻田.水稻材料、水稻材料×调查日期、水稻材料×调查年份、水稻材料×调查日期×调查年份对稻纵卷叶螟幼虫的种群动态均有显著影响.但是,3种转Bt基因水稻材料和非转基因水稻田间4种捕食类天敌的相对丰富度、种群密度以及种群动态基本没有显著差异.从上述结果可推论,转Bt基因水稻中的Bt蛋白能明显抑制稻纵卷叶螟的发生,但对4种捕食类天敌没有显著影响.     

稻纵卷叶螟雄蛾内生殖系统形态指标在性诱测报中的应用

【目的】随着性信息素在稻纵卷叶螟Cnaphalocrocis medinalis监测与防控中的应用越来越广泛,亟须准确判定性信息素所诱集到的雄蛾生殖发育状态,以便获取稻纵卷叶螟测报关键参数并准确评价防控效果。本研究旨在明确判定稻纵卷叶螟雄蛾内生殖系统发育状态的形态指标,进而试图依据性诱雄蛾日龄结构信息判定害虫种群发育状态。【方法】测量不同日龄的稻纵卷叶螟雄蛾精巢长半轴,形成依据精巢长半轴判断雄蛾日龄的发育标准,进而依据该标准划分田间逐日性诱的雄蛾日龄,反推出1日龄雄蛾逐日动态。【结果】解剖结果表明,在稻纵卷叶螟雄蛾内生殖系统各组成器官中,精巢形态稳定良好,其尺寸衰减与成虫日龄具有较好的对应关系,其中8日龄雄蛾精巢长半轴比1日龄长半轴减少41.55%。2015和2016年的田间调查结果表明,田间诱捕稻纵卷叶螟雄蛾中1-4日龄雄蛾占60%以上,不同日龄成虫的比例曲线呈双峰形,1和4日龄雄蛾分别形成第1和2次高峰。利用2015年四川眉山、2016年四川自贡两地性诱雄蛾逐日日龄结构和数量,反演1日龄雄蛾发生动态,其结果与田间发生情况相符合。【结论】稻纵卷叶螟雄蛾精巢大小变化可以准确反映稻纵卷叶螟雄蛾日龄变化,检测雄蛾精巢可获得其相应日龄信息,有利于准确预报该虫种群动态。     

Cd胁迫对舞毒蛾幼虫食物利用的影响及其Cd的外泌机制

为探明植食性昆虫对受重金属胁迫的寄主植物的生理生态响应机制,本研究用Cd胁迫下银中杨的叶片饲养舞毒蛾幼虫,分析舞毒蛾幼虫对食物的利用情况以及其对Cd的排毒代谢机制.结果表明: 取食Cd胁迫下银中杨的叶片后,舞毒蛾3～6龄幼虫体内的Cd浓度和Cd含量均显著高于对照,但随着幼虫龄期增长,其体内Cd浓度显著降低,而Cd含量有不同程度的提高;舞毒蛾幼虫粪便和虫蜕中的Cd浓度均显著高于对照;舞毒蛾3～5龄幼虫的食物消耗率显著高于对照,而转化率显著低于对照;3～4龄幼虫的食物利用率均与对照差异不显著,但在5龄时显著低于对照.说明在Cd胁迫下,舞毒蛾幼虫能通过有效的排毒代谢途径将体内富集的部分Cd排出体外,且高龄幼虫的排毒代谢能力强于低龄幼虫;舞毒蛾幼虫体质量的增加会对体内的Cd浓度形成一种稀释效应;舞毒蛾幼虫能通过调整食物消耗率和转化率之间的比例,来维持其正常生长发育所需的食物利用率,但超过一定限度后仍会造成食物利用率降低.     

春尺蠖生物学特性研究

【目的】为新疆北疆地区春尺蠖Apocheima cinerarius预测预报工作提供理论依据。【方法】本文在林间对春尺蠖的各虫态进行详细调查,记述了各虫态的形态特征、生活史、性比、行为与习性。【结果】春尺蠖蛹主要集中分布在树盘基部30~60 cm、土壤深度为20~30 cm范围的土层中,成虫羽化后,次日19:00—23:00或第3天下午4:00—6:00交尾,其交配行为是多次交配型。雌虫比雄虫羽化稍早,雌虫平均寿命为16~18 d,雄虫平均寿命为8~13 d。翌日黄昏开始产卵,卵期最长34 d,最短26 d,雌虫每天平均产卵块数最高达5.1块/头、平均卵粒数为363.1粒/头,最低为1块/头、平均卵粒数为86粒/头,平均孵化率为86%。1、2龄幼虫食叶量较低,3龄开始暴增,5龄最高,平均每日食叶量可达443 mm2/头。【结论】春尺蠖成虫按翅面斑纹和颜色,可分三种类型:深色型、常见型、浅色型。幼虫的头壳与虫龄呈显著直线正相关。幼虫1~2龄期间,死亡率较高,高达60.37%;4~5龄幼虫,死亡率较低,且食叶量占总食叶量的85.81%。所以应选择在3龄幼虫高峰期之前进行防治。雌雄比为1︰0.7068,可预测下一代种群数量呈上升趋势。     

茶黑刺粉虱蛹和卵的发育分级及与其防治适期的相关性

20 0 0年 4～ 6月 ,每 5日在皖南黑刺粉虱Aleurocanthusspiniferus(Quaintance)常发茶园中以平行跳跃法选 5 0个样方。每样方为 1m茶行 ,查其上、中、下层各 2片成叶上各虫态粉虱的数量 ;采回 2 0 0头蛹于立体显微镜下解剖。越冬代蛹期 32～ 38d。据蛹体形态和颜色的显著变化而分为 4级 :体液乳白色( 1 2～ 1 4d)、体液淡黄色 ( 6～ 8d)、体液橙红色 ( 1 1～ 1 2d)和体液淡紫色阶段 ( 3～ 4d)。引入该粉虱于盆载茶苗上 ,观察其生物学习性。第 1代卵期 2 2～ 2 8d ,据卵颜色的显著变化分为 4级 :乳白色 ( 2～ 4d)、淡黄色 ( 2～ 3d)、橙红色 ( 1 5～ 1 7d)和紫黑色阶段 ( 3～ 4d)。第 1代幼虫期 2 5～ 2 8d ,其中 1龄 9～ 1 2d ,2龄 9d ,3龄 7d ,蛹期 7～ 8d。越冬代成虫盛期和第 1代 1龄盛期为防治适期 ,可较好地用蛹或卵的分龄分级法预测。越冬代蛹全部羽化之时 ,又恰是 1龄幼虫盛期 ,易于掌握     

Stage-dependent effects of 20-hydroxyecdysone on DNA synthesis of corpus allatum cells in the silkworm,Bombyx mori

DNA synthesis in cells of the corpus allata (CA) of the silkworm, Bombyx mori, was studied immunocytochemically after in vivo labeling with 5-bromo-2'-deoxyuridine (BrdU); developmental changes during the 3rd, 4th, and last larval instars and effects of 20-hydroxyecdysone treatment were examined. During both the 3rd and 4th larval instars, the number of DNA-synthesizing cells fluctuated, and relatively low levels were observed during the middle stages. On day 0 of the last larval instar, the number of DNA-synthesizing cells per gland was 9.2, which then increased on day 1 and remained at levels ranging from 12.9 and 16.9 cells per gland. A major peak level (28 BrdU-labeled cells per gland) occurred on day 8, two days after larvae entered the wandering stage. When last instar larvae were fed 20-hydroxyecdysone-supplemented mulberry leaves starting on day 0 or 1, the number of DNA-synthesizing cells dramatically decreased to very low levels and these low levels were maintained throughout the remainder of the instar. However, no effect was observed when last instar larvae were fed 20-hydroxyecdysone-supplemented mulberry leaves starting on day 3, indicating the stage-specific action of 20-hydroxyecdysone. The mechanism by which 20-hydroxyecdysone treatment inhibits DNA synthesis of CA cells was further examined by using continuous in vitro BrdU labeling for a 2-day incubation. It was found that the decrease in responsiveness of DNA synthesis of CA cells of 20-hydroxyecdysone-treated larvae to stimulation by growth factors from hemolymph may have been, at least in part, responsible for the indirect inhibitory effects of 20-hydroxyecdysone.     

Effects of oxygen deficiency on survival and glycogen content of Chironomus anthracinus (Diptera,Chironomidae) under laboratory and field conditions

Growth and glycogen content of Chironomus anthracinus in Lake Esrom, Denmark was examined during summer stratification in 1992 and 1993. Simultaneously, effects of oxygen deficiency on glycogen utilization and survival were experimentally studied. The population consisted of almost fullgrown 4th instar larvae in 1992 and 2nd and 3rd instar larvae in 1993. Growth rate and glycogen content changed as hypolimnetic oxygen deficiency increased. During a 1st phase of stratification dry weight and glycogen content increased (2nd and 3rd instars) or was almost constant (4th instar) but decreased significantly during the following 2nd phase. This change from growth to degrowth and utilization of endogenous glycogen reserves correlated with a change in the thickness of the microxic layer (<0.2 mg O₂ 1^–1) above the sediment surface. The layer increased from 2–3 m in phase 1 to 4–5 m in phase 2, and we suggest that this deteriorated the oxygen conditions and resulted in a change in larval energy metabolism from fully aerobic during the 1st phase to partly anaerobic in the 2nd phase. During the 2nd phase larval metabolism was estimated at less than 20% of normoxic rate. Experimental exposure of the larvae to anoxia indicated highly different survival of young larvae (2nd and 3rd instars) and older larvae (large 4th instars). The morality of young larvae was 50% after three days in anoxia at 10 °C, whereas only 25% of the older larvae had died after 3–4 weeks under similar conditions. Extending the treatment, however, resulted in increased death rate of the 4th instar larvae with only 10% surviving after seven weeks. The anaerobic metabolism of 4th instar larvae as estimated from glycogen degradation at 10 °C was 5% of normoxia in the interval from 0–5 days but 1.5% in the interval from 20–25 days. It is concluded that survival of C. anthracinus in anoxia is very limited, but traces of oxygen in the environment allowing for faint aerobic metabolism prolong the survival time of the larvae from a few days (2nd and 3rd instars) or a few weeks (4th instar) to probably 3–4 months.     

亚麻荠对小菜蛾幼虫取食和成虫行为反应的影响

亚麻荠是一种很少有害虫危害的油料作物。用室内生测和Y 型嗅觉仪研究了亚麻荠对小菜蛾Plutella xylostella幼虫取食和成虫行 为反应的影响。以甘蓝作对照,用亚麻荠叶片喂养的小菜蛾初孵幼虫3天后校正死亡率为79 .2%,显示了较强的致死作用;喂养小菜蛾3龄幼虫至化蛹,其存活率、化蛹率、蛹重及成 虫寿命都显著降低,表明亚麻荠对小菜蛾幼虫的生长发育有不利影响。在幼虫的取食选择实 验中,有甘蓝叶供选择时,小菜蛾幼虫不取食亚麻荠;在无可选择的情况下,小菜蛾幼虫也 取 食亚麻荠叶片,但取食量很小,与取食甘蓝叶的量相比,差异极显著。行为反应测试表明, 小菜蛾成虫对甘蓝和亚麻荠植株的挥发物都有明显的趋性反应,与对照（净化空气）相比, 差异极显著,而在甘蓝和亚麻荠之间无选择性。说明小菜蛾成虫对亚麻荠植株的挥发物具有 较强的定向反应。     

Choristoneura fumiferana entomopoxvirus prevents metamorphosis and modulates juvenile hormone and ecdysteroid titers

Larvae of the spruce budworm, Choristoneura fumiferana, infected with C. fumiferana entomopoxvirus (CfEPV) continue to feed and grow without undergoing metamorphosis and die as moribund larvae. The lethal dose (LD(50)) and lethal time (LT(50)) values for fourth instar larvae are 2.4 spheroids and 25.2 days, respectively. One hundred percent of the control fourth instar larvae, which were fed water instead of virus, pupated by 18 days post feeding (PF). Only 30% of the larvae that were fed the LD(50) dose and none of the larvae that were fed the LD(95) dose pupated by 18 days PF. Of the control larvae, 95% became adults by 24 days PF, whereas in the treated group only 2% of larvae that were fed the LD(50) dose and none of the larvae that were fed the LD(95) dose became adults by 24 days PF. Some of the virus-treated larvae died as either larval/pupal or pupal/adult intermediates. These phenotypic effects were similar to the larval/pupal and pupal/adult intermediates, resulting from treating larvae with juvenile hormone (JH) or its analogs, which suggests that EPV may cause such abnormalities by modulating JH and/or ecdysteroid titers. In untreated sixth instar larvae the JH titer decreased to low levels by 24 h after ecdysis and remained low throughout larval life. EPV-fed sixth instar larvae had 2112 pg/ml on day 0, 477 pg/ml on day 1 and 875 pg/ml on day 8 of the sixth instar. Control larvae contained 860 ng of ecdysteroids per ml hemolymph on day 8 of the sixth instar, whereas EPV-treated larvae of the same age (30 days PF) had only 107 ng of ecdysteroids per ml of hemolymph. Thus, EPV infection results in increased JH titer and decreased ecdysteroid titer. Northern hybridization analysis was performed using RNA isolated from control and EPV-fed larvae and cDNA probes for (i) juvenile hormone esterase (JHE), which is JH inducible, (ii) Choristoneura hormone receptor 3 (CHR3), which is ecdysteroid inducible, and (iii) larval specific diapause associated protein 1 (DAP1), whose expression is larval specific. EPV-treated larvae showed higher levels of JHE and DAP1 mRNA and lower levels of CHR3 mRNA, indicating that they had higher levels of JH and lower levels of ecdysteroids. Thus, our data show that EPV prevents metamorphosis by modulating ecdysteroid and JH levels.     

Response of Danaus plexippus to pollen of two new Bt corn events via laboratory bioassay

Laboratory bioassays were conducted to evaluate the response of first instar larvae of the monarch butterfly, Danaus plexippus L. (Lepidoptera: Danaidae), a non‐target species, to pollen from corn, Zea mays L. (Commelinales: Poaceae), from two new corn hybrids genetically modified to express different types of insecticidal proteins derived from the bacterium Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) (Bt). One hybrid expresses both Cry1Ab and Cry2Ab2 proteins (MON 810 × MON 84006), active against lepidopteran pests, and the other expresses Cry3Bb1 protein (MON 863), targeted against coleopteran pests. First instar larvae were placed on milkweed leaves (Asclepias syriaca L.) (Gentianales: Asclepiadaceae) dusted with doses of either Bt pollen or its nonexpressing (isoline) pollen counterpart ranging from 50 to 3200 grains cm^?2 of milkweed leaves, or no pollen at all. Larvae were exposed to pollen for 4 days, then moved to pollen‐free leaves and observed for another 6 days. Survival was observed after 2, 4, and 10 days. Weight gain was estimated after 4 and 10 days, leaf consumption after 2 and 4 days, and larval development after 10 days. Exposure to pollen of the Cry1Ab/Cry2Ab2‐Bt expressing hybrid reduced larval survival approximately 7.5–23.5% at the dose ranges tested relative to a no pollen control. Larval weight gain and consumption were reduced for larvae exposed to pollen of this hybrid and a small minority of larvae (3.1%) never developed past the third instar after 10 days of observation. Exposure to pollen of the Cry3Bb1‐Bt expressing hybrid had no negative effects on larval mortality, weight gain, consumption, or development relative to the consumption of Bt‐free corn pollen. The relevance of these findings to the risk that these Bt corn hybrids pose to monarch populations is discussed.     

Induced emissions of apple fruit volatiles by the codling moth: changing patterns with different time periods after infestation and different larval instars

The changes in the emission of volatiles from mature apple fruits in response to larval feeding by the codling moth (Cydia pomonella) under laboratory conditions are reported. A time course experiment investigated the emission of volatiles throughout the period of larval development following infestation. The volatiles consisted mainly of esters, a few aldehydes, and the terpene alpha-farnesene. Infested apples emitted the same compounds as healthy apples. The quantities of volatiles released were much higher for infested as compared to healthy fruits for an initial three day period. Following this period there was a decrease in volatile emissions (days 6-9), eventually declining back to the levels emitted from healthy apples or below by 9-21 days after infestation. In a separate experiment, the volatile emissions from healthy and artificially damaged fruits were compared to those from herbivore damaged fruits for each of the five larval instars of C. pommonella. The results from the discriminant analysis indicate that the most effective induction of volatiles occurred when fruits were infested with first instar larvae. Induction by first instar larvae was generally higher than after infestation by later instars, and for most compounds it also exceeded the emission from artificially damaged fruits.     

麻疯树蛀梢斑螟生物学特性观察及其防治药剂筛选

本文对攀西地区麻疯树(Jatropha curcasL.)人工林中的麻疯树蛀梢斑螟Oncocera faecella Zeller进行了生物学特性观察及其防治药剂筛选的研究。结果表明:该虫在攀西地区1年发生5代,每雌产卵量为(29±17.05)个,卵期(7±1)d,孵化率93.23%;幼虫共4龄,1、2龄取食量小,占整个幼虫生长阶段的10.6%,3、4龄幼虫取食量大,占整个幼虫生长阶段的89.4%;蛹期(13.11±1.05)d,雌雄比为1.04(F)∶1(M),羽化率88.96%。成虫寿命为6～8d。初孵幼虫仅取食叶肉,后缀嫩叶为害梢头,老熟幼虫在叶片上或枯枝落叶中织茧化蛹;以老熟幼虫越冬。对2龄和3龄幼虫进行防治药剂筛选,表明4.5%高效氯氰菊酯1.0×103mg·L-1和0.5×103mg·L-1、30%乙酰甲胺磷乳油0.5×103mg·L-1和0.25×103mg·L-1有很好的防治效果。