劳氏黏虫在4种寄主植物上的生长发育和繁殖

【目的】明确寄主植物对劳氏黏虫Leucania loreyi(Duponchel)生长发育和繁殖的影响。【方法】在温度(24±1)℃、湿度(75±5)%、光周期为12 h光∶12 h暗的室内条件下,分别以玉米、水稻、甘蔗和稗草叶片为寄主植物,观察劳氏黏虫各虫态发育历期、存活率、蛹质量、成虫繁殖力并计算生命表参数。【结果】劳氏黏虫幼虫历期取食玉米时间最短,为20.18 d,取食甘蔗时间最长,为25.24 d。非成虫期存活率在玉米上最高(68%),在稗草上最低(58%);雌成虫蛹质量以取食玉米的最高(32.43 mg),取食稗草的最低(22.61 mg);取食玉米的产卵量最多,单雌产卵量为1 019.42粒,取食甘蔗的产卵量最少,单雌产卵量为665.27粒。劳氏黏虫在玉米、水稻、甘蔗和稗草上的内禀增长率(rm)分别为0.13、0.12、0.10和0.10,净增殖率(R0)分别为226.54、211.48、153.71和171.85。【结论】在4种寄主植物中,玉米为劳氏黏虫最优寄主,其次是水稻,甘蔗和稗草可作为寄主或中间寄主。     

噻虫嗪种衣剂对玉米苗期两种粘虫的室内毒力测定

本研究采用胃毒法测定了噻虫嗪悬浮种衣剂(SC)对东方粘虫[Mythimna separata(Walker)]和劳氏粘虫[Mythimna loreyi(Duponchel)]的室内毒力。结果表明，35%噻虫嗪SC有效成分质量浓度在1.12～2.24 g/kg之间对两种粘虫均具有明显的毒力，且在玉米不同苗龄对不同龄期及种类粘虫的毒力均存在一定差异。玉米出苗2周，噻虫嗪SC质量浓度为1.12 g/kg时对东方粘虫2龄幼虫的毒力效果达92.83%,对劳氏粘虫2龄幼虫的毒力效果达57.13%。与劳氏粘虫相比，噻虫嗪SC对东方粘虫的毒力更强。本研究为生产上选用噻虫嗪SC防治玉米粘虫提供了参考。     

粘虫的发生危害及防治

粘虫俗称剃技虫、行军虫，属鳞翅目夜蛾科，有三个种，普通粘虫、劳氏粘虫和白脉粘虫。我乡以普通粘虫危害为主，其次是劳氏粘虫。幼虫取食水稻、玉米、小麦、甘蔗等禾本科作物的幼嫩茎叶、穗，轻者吃成缺刻，重则吃光叶片，幼茎，穗，直接影响营养生产和生殖生长，一般减产产5%-20%，严重时则造成颗粒无收。     

劳氏粘虫的生物学特性及危害规律研究

田间系统调查和室内饲养观察表明 ,劳氏粘虫在漯河市 1年发生 3～ 4代 ,主要危害玉米 ,取食叶片、花丝和籽粒 ,其幼虫寄生天敌的种类主要是姬蜂和绒茧蜂 ,影响劳氏粘虫发生的主导因素是气候因子。     

暴发性害虫玉米劳氏粘虫发生规律和综合防治

劳氏粘虫是鳞翅目夜蛾科害虫,主要为害水稻、玉米等禾谷类作物。过去在遂平县属于次要害虫。从1999年大发生以来,对玉米造成的危害日益严重,已经成为玉米主要害虫之一。据田间调查,害虫第1、2代幼虫取食叶片,受害严重的地块,叶片被食成缺刻,重者仅留叶脉;第3、4代幼虫取食雌穗花丝和子粒,花丝被咬至苞叶齐,全田几乎不见花丝,导致部分子粒不育,钻入雌穗的幼虫取食子粒,并排粪其中,污     

5种寄主植物对台湾稻螟生长发育的影响

[目的]明确不同寄主植物对台湾稻螟生长发育的影响,为台湾稻螟的预测预报和综合防治提供理论依据.[方法]在温度27.5℃、相对湿度80%、光照L:D=12 h:12 h的条件下,用水稻、薏苡、甘蔗、玉米和茭白5种寄主植物分别饲养台湾稻螟幼虫100头,记录幼虫的死亡数、雌雄蛹数、蛹重、蛹长、蛹存活率和雌雄性比;每种寄主植物单头饲养幼虫25头,每天定时观察记录不同寄主植物上每头台湾稻螟幼虫各龄历期和蛹期.[结果]台湾稻螟在水稻、薏苡、甘蔗、玉米和茭白上取食,2龄幼虫至蛹的发育历期依次为10.12、13.00、9.52、14.69和14.96 d,幼虫存活率依次为51.00%、30.00%、27.00%、26.00%和59.00%,蛹存活率依次为68.63%、83.33%、74.07%、53.85%和88.13%,雌雄蛹重分别为4.9、4.1、4.4、4.8、5.0和3.1、2.9、3.6、3.6、3.1 mg/头,雌雄蛹长分别为12.29、11.59、11.75、11.67、11.98和10.71、10.21、10.39、11.37、10.40 mm/头,雌雄虫性比依次为2.00、1.14、0.42、1.60和0.72.[结论]水稻最有利于台湾稻螟生长发育,茭白次之.     

粘虫生长发育和寄主选择性与不同玉米品种生化物质含量的关系

为明确粘虫的生长发育、寄主选择性与不同玉米品种生化物质含量的关系,在室温24±1℃,RH70%～80%和光周期14L∶10D条件下,观察了粘虫实验种群在22个玉米品种上的生长发育、取食和产卵选择性,测定了22个品种中4种生化物质的含量。结果表明:粘虫在不同玉米品种上的发育历期和蛹重具有显著差异,但羽化率无显著差异。其中,幼虫至成虫发育历期最短的品种是黔单16,为26.14 d,最长的是8017,达29.36 d;取食安单3号的蛹最重,达346.84 mg,而取食品种7079的蛹最轻,仅298.71 mg。从化蛹率来看,取食黔单16的化蛹率最高,为93.33%,取食8021的最低,仅有66.87%。粘虫在不同玉米品种上的产卵和取食具有明显的选择性,尤为喜好在黔单16上产卵(5.67块·株~(-1))和取食(9.00头·株~(-1))。不同品种间总酚、类黄酮和总蛋白含量差异显著,但总糖含量差异不显著。相关性分析表明,粘虫生长发育相关指标与4种生化物质含量无明显相关性,说明粘虫的生长发育与这4种物质含量无关。粘虫在22个玉米品种上的生长发育历期、存活及寄主选择性具有显著差异,但这种差异与不同品种间4种生化物质含量无关。     

广西稻田粘虫及其寄生性天敌昆虫发生种类调查初报

【目的】调查广西稻田粘虫及其寄生性天敌昆虫发生种类,为粘虫的预测预报及可持续防控提供科学依据。【方法】在不同调查点进行田间调查,将粘虫幼虫和蛹带回室内饲养,待羽化后鉴定其种类,并对期间饲养出的寄生性天敌昆虫进行种类鉴定。【结果】广西稻田共发现3种粘虫,分别为东方粘虫Mythimna separata(Walker)、劳氏粘虫Mythimna loreyi(Duponchel)和淡脉粘虫Mythimna roseilinea(Walker);共发现6种寄生性天敌昆虫:螟蛉绒茧蜂Apanteles ruficrus(Haliday),寄生率可达20%;粘虫绒茧蜂Apanteles kariyai Watanabe,寄生率可达14.29%;斜纹夜蛾盾脸姬蜂Metopius(Metopius)rufus browni(Ashmead),寄生率为2.22%;粘虫白星姬蜂Vulgichneumon leucaniae Uchida,寄生率为18.53%;粘虫长芒寄蝇Dolichocolon klapperichi Mesnil,寄生率为2.22%;日本追寄蝇Exorista japonica Townsend,寄生率为0.42%。【结论】广西稻田3种粘虫中,以东方粘虫为害水稻最为严重;越冬粘虫主要有东方粘虫和劳氏粘虫。螟蛉绒茧蜂为越冬粘虫寄生性天敌昆虫优势种。     

叉角厉蝽成虫对粘虫幼虫的捕食功能反应

[目的]探明室内叉角厉蝽对粘虫幼虫的捕食潜力,为叉角厉蝽应用于田间防治粘虫提供理论依据.[方法]以透明塑料盒为测试容器,在室内设不同密度(3、6、9、12和15头/盒)的3、4和5龄粘虫幼虫供叉角厉蝽成虫(1头/盒)取食,统计叉角厉蝽成虫的捕食量并进行相关分析.固定粘虫幼虫密度(50头/盒),设不同密度(1、2、3、4和5头/盒)的叉角厉蝽成虫,研究捕食者自身密度对捕食量的影响.等比例(天敌:猎物=1:10)增加叉角厉蝽成虫和粘虫幼虫,研究干扰反应对捕食量的影响.[结果]叉角厉蝽成虫对3、4和5龄粘虫幼虫的捕食功能反应均符合HollingⅡ模型.在室内条件下,叉角厉蝽成虫对4和5龄粘虫幼虫的理论最大取食量分别为10.09和3.55头,明显低于对3龄粘虫幼虫的理论最大取食量(78.74头).叉角厉蝽成虫对3、4和5龄粘虫幼虫的搜寻效应方程分别为S=0.9009/(1+0.0114N)、S=0.7291/(1+0.0723N)和S=0.9322/(1+0.2626N),在相同虫龄内,搜寻效应随着猎物密度的增加而减小.捕食者密度对搜寻效应的影响及干扰反应的拟合结果分别为E=0.4254P-0.551和A=8.3413P-0.127,随着捕食者密度的增加,叉角厉蝽的平均捕食量都会逐渐减少,叉角厉蝽成虫与粘虫幼虫等比例增加时,叉角厉蝽也会产生种间干扰.[结论]叉角厉蝽成虫对3龄粘虫幼虫具有较好的捕食潜力,因此选择粘虫幼虫3龄时释放叉角厉蝽成虫为宜,但在田间实际释放时需考虑叉角厉蝽自身密度及种间干扰对其捕食能力的影响.     

草地贪夜蛾对4个玉米品种的产卵和取食选择特性

选用云南省保山市3种类型4个常见的玉米品种：甜质型玉米“正甜99”、糯质型玉米“花糯168”及饲用型玉米“恩白玉3号”和“富玉6号”,采用自由选择法测定草地贪夜蛾在不同玉米品种上的产卵量、幼虫生长发育历期和取食选择率。结果表明,草地贪夜蛾在4个玉米品种上的产卵量具有显著差异(P<0.05),以在正甜99上的卵块数和卵粒数最多,分别为12.67块和1 001.67粒,而在其他3个玉米品种间无显著差异(P>0.05);取食不同玉米品种的草地贪夜蛾幼虫总历期、蛹历期和成虫寿命也有显著差异(P<0.05),其中以取食富玉6号的幼虫总历期、蛹历期最长,分别为17.09、10.93 d,成虫寿命则以取食正甜99的最长,为13.89 d;草地贪夜蛾3～6龄各龄期幼虫对4个玉米品种的取食选择具有明显趋向性,均以对正甜99的取食选择率最高,显著高于对其他3种玉米品种的取食选择率(P<0.05)。研究结果可为不同类型玉米上草地贪夜蛾的防控提供参考。     

劳氏粘虫幼虫在玉米田的空间分布及抽样技术研究

运用频次分布、聚集度指标法等方法对劳氏粘虫的空间分布型进行了研究。结果表明，劳氏粘虫幼虫在玉米田呈聚集分布，同时符合负二项分布，在空间分布空间研究的基础上提出了理论抽样数。     

广西玉米主要种植区草地贪夜蛾发生及为害情况调查

【目的】明确草地贪夜蛾（Spodoptera frugiperda）在广西玉米主要种植区的种群动态及发生为害规律,为草地贪夜蛾周年繁殖区和其他玉米主产区草地贪夜蛾的预测预报和精准防控提供科学依据。【方法】2020年在广西崇左市、南宁市和河池市选择7个固定调查监测点,采用对角线五点取样法,在玉米生长期每隔7 d调查草地贪夜蛾幼虫数量及对玉米植株的为害特征,计算植株受害率和百株虫量;在7个调查监测点各放置2组桶型诱捕器和诱芯,每隔7 d调查记录1次诱虫情况,统计成虫数量。【结果】各调查点草地贪夜蛾幼虫发生量春秋季各有1次高峰,春秋季百株虫量最高值分别为35.00头和64.67头,秋季虫量明显高于春季。幼虫发生动态呈区域性差异,崇左市扶绥县、南宁市江南区和武鸣区幼虫发生期较短且集中,3个点春季百株虫量和峰值均较高。玉米各生育期均受幼虫为害,苗期以低龄幼虫为主,开花期和成熟期以5~6龄幼虫为主,其他生育期可见各龄期幼虫,世代重叠明显。各调查点春季草地贪夜蛾成虫数量总体上呈抛物线增加趋势,春季每诱虫桶最高虫量为25.33头;秋季虫量呈波浪状,约21 d出现一次峰值,每诱虫桶最高虫量为34.67头;秋季成虫数量总体上高于春季。【结论】草地贪夜蛾在广西全年均可发生,年发生代数在7代及以上,秋季虫量明显高于春季,发生程度随温度升高而加重。幼虫发生期和虫量存在区域差异,幼虫可为害各生育期玉米。草地贪夜蛾严重为害玉米生长,应进一步加强监测预报,根据区域气候和玉米长势,强化低龄幼虫和成虫高峰期的防控力度,以降低草地贪夜蛾造成的危害。     

Effect of three insect-resistant maizes expressing Cry1Ie,Cry1Ab/Cry2Aj and Cry1Ab on the growth and development of armyworm Mythimna separata(Walker)

Three transgenic maize events(IE09 S034, Shuangkang 12–5 and C0030.3.5) produced Cry1 Ie, Cry1 Ab/Cry2 Aj and G10-EPSPS, Cry1 Ab and EPSPS, respectively, all of which target the Asian corn borer. The oriental armyworm Mythimna separata(Walker) is the secondary target. In this study, the effects of the three Bt maizes on the development and survival of armyworm were studied. The results showed that IE09 S034 had insecticidal activity against 1 st instar larvae, and the survival rate of armyworm fed with Bt maize for 10 days was 46.2%, significantly lower than that of the control. The larvae at 3 rd–6 th instar were more tolerant of the Bt toxin than the early instar larvae. However, Shuangkang 12-5 had good insecticidal activity against 1 st–5 th instar larvae. The mortality was nearly 100% when the larvae were fed with Shuangkang 12-5 before 3 rd instar, and the toxin had quick-acting efficacy. This event significantly inhibited the development of armyworm; that is, the larval duration of the 3 rd and 4 th instar larvae fed with Shuangkang 12-5 was prolonged by 4.5 and 3.0 days, respectively. The pupal weight and egg number were also significantly lower than those of the control. For C0030.3.5, it could control 1 st–5 th instar larvae effectively. The mortality rates were all over 50% if 1 st–3 rd larvae were fed with this event. The pupal weight of 4 th–6 th instar larvae fed with Bt maize were only 53.9, 56.8 and 54.6%, respectively, compared to that of the control. The number of eggs laid was significantly less than the control. The results indicate that all three transgenic maize events exhibit the potential to provide effective control of early instar larvae of armyworm, which can be commercialized in future to control lepidoptera pests such as Asian corn borer and armyworm.     

松油烯-4-醇对粘虫体内保护酶活力的影响

以松油烯-4-醇处理粘虫5龄幼虫后,测定了兴奋期、痉挛期、麻痹期及复苏期4个中毒阶段试虫的保护酶活性。结果表明,超氧化物歧化酶(SOD)被明显激活,各中毒阶段的酶活力均极显著高于对照,其中兴奋期的酶活力最大,为对照的3.04倍;处理试虫的过氧化氢酶(CAT)在兴奋期和痉挛期与对照的差异不大,而在麻痹期和复苏期被明显抑制,酶活力分别为对照的78%和92%;过氧化物酶(POD)也被明显抑制,各中毒阶段的酶比活力依次为对照的81%,86.0%,65.0%和90.0%。分析认为,中毒试虫的复苏可能与POD和CAT活力的变化有关。     

吉林省春季粘虫发生预测模式研究

以我国东部粘虫Mythimnaseparata(Walker)一代成虫迁飞期公主岭地面诱蛾量和同期降雨量的数据为预测因素,该世代成虫繁殖的危害种群在吉林省的发生程度和发生面积为预测目标,应用逐步回归法研究发生预测的数学模型。用Basic语言的计算机程序完成了计算、分析、筛选、组建多元回归方程式并与历年数据拟合的过程,提出了吉林省春季粘虫的发生预测模式。     

粘虫室内饲养方法的改进

为了提高粘虫室内饲养的效率,满足实验室用虫需求,在传统饲养粘虫方法的基础上,对粘虫卵、幼虫、蛹和成虫的饲养器具以及操作方法进行了简化与改进：将产于塑料绳上的卵消毒晾干后,直接放于塑料保鲜袋中孵化;初孵幼虫置于33 cm×33 cm的100目锦纶纱养虫袋中饲养,3龄前用天然饲料饲喂,3龄后用人工饲料饲喂,直至幼虫老熟;将老熟幼虫放到35 cm×25 cm×10 cm的化蛹盒中化蛹,以吸水纸替代沙土作为化蛹介质。比较了饲养方法改进前后粘虫的卵孵化率,低龄幼虫存活率,粘虫生长发育和繁殖,以及化蛹效果。结果表明：与改进前的饲养技术相比,采用改进后的饲养技术饲养粘虫不仅操作简单、省工省时、工作效率提高,而且能够显著提高卵的孵化率和低龄幼虫的存活率。改进前用塑料盒饲养,每盒饲养20头比较适宜,而改进后每个养虫袋可以饲养幼虫50～70头,且粘虫的发育和生殖参数与改进前相当。利用改进后的粘虫室内饲养方法,能够实现室内粘虫的继代繁殖和批量饲养。     

Effect of Host Plants on Development,Fecundity and Enzyme Activity of Spodoptera exigua （Hübner）（Lepidoptera：Noctuidae）

The beet armyworm,Spodoptera exigua (Lepidoptera:Noctuidae),is an economically important pest of crops worldwide,attacking plants from over 20 families including trans-continental agricultural cotton,corn and citrus crops.In this study,performance and subsequent enzyme activity of beet armyworm reared on host plants from five families were investigated.Significant differences were found in development,fecundity and enzyme activity on different host plants.Survival rate was the highest (42.8％) on asparagus lettuce (Lactuca sativar var.asparagina) and the lowest (17.0％) on sweet pepper (Capsicum annuum).Larval duration was the shortest on asparagus lettuce (12.0 d),and was 43.4％ longer on sweet peppers (21.2 d).The activity of acetylcholine esterase (AChE) and carboxylesterase (CarE) in 3rd instar larvae,and soluble carbohydrate and crude protein contents in different host plants were determined.AChE activity was the highest in the larvae feeding on Chinese cabbage (Brassica rapa),but declined by nearly 60％ on maize (Zea mays) seedlings.The ratio of soluble carbohydrate content to crude protein content in host plants was found to have a positive effect on oviposition and a negative correlation with larval duration and life time (from larval to adult stages) of the insect.     

吉林省二代粘虫预测模式研究

以我国东部粘虫 (MythimnaseparataWalker)年发生第二代成虫公主岭地面诱蛾量和同期降雨量的数据为预测因素 ,该世代成虫繁殖的危害种群在吉林省的发生面积为预测目标 ,应用回归相关法研究发生预测的数学模型 ,用Basic语言计算机程序计算并进行分析与拟合 ,提出了吉林省二代粘虫预测模式。     

稻纵卷叶螟幼虫对不同含氮糖人工饲料的取食选择行为

稻纵卷叶螟是我国水稻上重要害虫,由于其难以在室内大规模饲养使得诸多研究受到限制。试验在已有可以完成世代的人工饲料的基础上分别配置了5种不同氮含量和糖含量的人工饲料,观察稻纵卷叶螟初孵、3龄和5龄幼虫对不同氮、糖含量的人工饲料取食选择性。结果表明,初孵幼虫较喜欢取食糖含量较高的人工饲料;氮含量饲料总体对初孵幼虫选择性的影响不显著,但接虫2 h后,饲料氮含量显著影响幼虫的选择性,其中0.92%氮含量饲料上的落虫数占总数的36%,接虫48 h后,氮含量为1.16%的饲料上落虫数明显高于其他饲料。糖含量对3龄幼虫落虫数取食选择有显著影响;对于不同氮含量的人工饲料,稻纵卷叶螟3龄幼虫选择性显著受饲料含氮量的影响（P<0.001）,倾向于1.53%氮含量饲料。5龄幼虫对糖含量较高（27.22%）的人工饲料有稍强的趋向性,而不同含氮量对其选择性无明显影响。总体而言,糖含量对稻纵卷叶螟的取食选择有重要影响,氮含量仅对3龄幼虫的取食选择有显著影响。     

Sub-Lethal Effects of Fenvalerate on the Development,Fecundity, and Juvenile Hormone Esterase Activity of Diamondback Moth,Plutella xylostella （L.）

The toxicities of fenvalerate （20% EC） to the 3rd instar larvae of diamondback moth （DBM）, Plutella xylostella （L.）, reared on three host plants viz., radish, oilseed rape, and cabbage were tested. The LC50 values of fenvalerate to the 3rd instar larvae of DBM varied with host plants, however, there wasn＇t any significant difference among them （P〉 0.05）. Similarly, DBM fed on three host plants had same pupal weight, pupal period, pupation rate, adult emergence rate, female ratio, and fecundity. The activity of juvenile hormone esterase （JHE, EC 3.1.1.1） in the 3rd instar larvae of DMB did not significantly vary with host plants, either. These suggested that DBM had similar fitness on the three host plant species. When fed on the host plants pretreated with fenvalerate at the concentrations equivalent to LC20, LC50 and LC50, the pupation rate, pupal weight, adult emergence rate, female ratio, fecundity, and JHE activity of the tested insects were declined as compared with insects in control treatments fed on the same host plant species. Furthermore, the pupal period of the tested insects was extended after fenvalerate treatment. The decrease in JHE activity after fenvalerate treatment in the tested insects could partly explain the changes in the mentioned growth parameters. Whether the role of fenvalerate in the inhibition of JHE activity could serve as a new way to control DBM needs further investigation.