不同生育期玉米上草地贪夜蛾的发生为害规律

2019年在广东湛江、江门调查了玉米上草地贪夜蛾Spodoptera frugiperda (Smith)发生为害动态,分析了不同生育期玉米上该虫发生为害差异规律。发现各个地区草地贪夜蛾的虫口数量与玉米受害程度存在较大差异,呈现不均衡性;该虫对玉米苗期为害最严重,其次为大喇叭口期;建立了2个地区玉米6个生育期受害率与虫口数量之间的线性回归模型。研究结果可为草地贪夜蛾监测预警及防控提供参考。     

草地贪夜蛾综合防控技术研究进展

草地贪夜蛾是世界重大入侵性害虫,我国于2019年初发现草地贪夜蛾大面积危害西南地区玉米、高粱、甘蔗等多种作物,随后迅速扩散至主要玉米产区,严重威胁和影响我国粮食安全。国内研究人员已开展了大量关于草地贪夜蛾监测预警与防控技术的研究,在其种群发生规律监测、迁飞路径研判、化学防治、生物防治、物理防治等方面取得了系列进展,基本明确了草地贪夜蛾在我国西南、江南江淮、北方各地区的发生与危害规律,建立了一套草地贪夜蛾综合防控技术体系,有效阻断了其大面积扩散危害。本文综述了2019—2022年间国内草地贪夜蛾防控技术的研究进展,以期为开发草地贪夜蛾综合防控技术提供参考。     

广东省草地贪夜蛾种群周年动态及发生特征

为了明确广东省草地贪夜蛾Spodoptera frugiperda(J. E. Smith)种群周年消长动态及发生特征,根据2020年和2021年广东省草地贪夜蛾性诱监测及田间调查数据,分析不同生态区草地贪夜蛾成虫及幼虫种群周年发生动态。结果表明：(1)草地贪夜蛾在广东省大部分冬种玉米区可以周年繁殖,仅在清远、韶关、河源等地未发现幼虫为害;不同地区之间草地贪夜蛾越冬虫源基数差异较大,粤西发生为害较重,珠三角及粤东地区发生相对较轻;(2)周年繁殖区草地贪夜蛾成虫和幼虫全年均可发生为害,而季节发生区一般于3-4月才零星始见草地贪夜蛾成虫和幼虫,且诱蛾量、幼虫种群数量及为害程度均相对较低;(3)广东省草地贪夜蛾种群消长动态呈多峰型,发生高峰期主要集中于5-10月,期间出现多个大小不等的高峰,但峰期、蛾量和虫量在不同地区之间差异较大。本研究明确了广东省不同生态区草地贪夜蛾种群的周年消长动态及发生特征,为广东省乃至全国草地贪夜蛾的早期预警和精准防控提供重要参考。     

草地贪夜蛾首次入侵广东地区发生为害调查

草地贪夜蛾Spodoptera furgiperda(J.E.Smith)是一种新的重要农业入侵害虫,目前已侵入我国云南、广西、广东等地。本研究调查了草地贪夜蛾首次入侵成虫后代幼虫在珠三角和粤北地区的种群密度和为害情况。结果表明:本次调查珠三角和粤北地区均已出现草地贪夜蛾取食为害,所调查的10种作物中,仅在玉米上发现取食为害;其中草地贪夜蛾幼虫在从化地区为害最重(虫口数量222头/百株、为害率80%),其次是连平(虫口数量98头/百株、为害率68%)、英德(虫口数量76头/百株、为害率62%)、增城(虫口数量66头/百株、为害率20%)和珠海(虫口数量46头/百株、为害率30%),新丰最低(虫口数量6头/百株、为害率3%)。本研究为监测草地贪夜蛾首次入侵的发生和为害提供依据,并为通过调查田间种群密度指导幼虫防治工作提供技术支持。     

草地贪夜蛾寄主适应性、种群动态特征及防控新思路展望

草地贪夜蛾Spodoptera frugiperda是一种原产于美洲热带和亚热带地区的重要入侵害虫,自2019年1月份入侵中国以来,迅速席卷国内多个省市,对我国的粮食生产系统造成巨大的压力。广东省丰富的作物资源和适宜的气候条件等,使其可能成为草地贪夜蛾入侵后种群恢复繁衍的大后方。因此,广东省草地贪夜蛾防控更为艰巨。草地贪夜蛾入侵我省乃至我国,将出现新的特征,使得草地贪夜蛾的防控局势变得复杂。本综述系统调研了草地贪夜蛾国内外的研究现状,包括在原产地及我国的寄主适应性、种群动态和防控措施等方面,并在现今组学及新技术高度发展的新形势下,对草地贪夜蛾入侵机制研究方法提出了一些展望,以期对草地贪夜蛾的有效防控提供参考依据。     

不同品种玉米对草地贪夜蛾生长发育及繁殖的影响

为评价新入侵害虫草地贪夜蛾对我国不同品种玉米的为害潜能,本文采用组建实验种群生命表的方法研究了草地贪夜蛾对3种甜质型玉米(穗甜1号、正甜68和华金甜1号)以及3种糯质型玉米(京科糯2000、广黑甜糯和广糯1号)的生存适合度,分析了草地贪夜蛾生物学指标与玉米叶片主要营养物质及粗纤维含量间的相关性。结果表明: 取食甜质型玉米的草地贪夜蛾的幼虫存活率、蛹重、雌成虫产卵量均显著高于取食糯质型玉米;取食甜质型玉米草地贪夜蛾的内禀增长率介于0.1566～0.1843,净生殖力介于187.97～353.35,也均高于取食糯质型玉米(内禀增长率介于0.0998～0.1465,净生殖力介于25.89～95.34),表明取食甜质型玉米的草地贪夜蛾具有更高的种群增长能力。甜质型玉米叶片中主要营养物质维生素C、淀粉、可溶性糖、蛋白质、脂肪、总氨基酸及粗纤维的含量普遍高于糯质型玉米,草地贪夜蛾的净生殖力与维生素C、淀粉、可溶性糖、蛋白质及粗纤维的含量均存在显著正相关关系。草地贪夜蛾在甜质型玉米上具有更高的生存适合度。     

2019-2021年河南省草地贪夜蛾监测方法与发生特点分析

【目的】明确河南省草地贪夜蛾Spodopterafrugiperda的发生特点与科学监测方法,提高本地草地贪夜蛾监测的精准度。【方法】对2019-2021年河南省利用多种方法监测到的草地贪夜蛾数据进行综合分析。【结果】2019-2021年均在田间查到幼虫为害之后,才监测到成虫。在各县采用的成虫监测方法中,以性信息素诱集法首次监测到成虫的次数最高,以探照灯诱集法诱捕到的成虫数量最多。2019年河南省内最早见虫的地区是豫南,之后依次为豫西南、豫西、豫中、豫东和豫北;2020和2021年最早见虫的地区均在豫西南,之后依次为豫南、豫中、豫东、豫西和豫北。豫南和豫西南地区7月份始见成虫并一直持续到10月中下旬,豫中、豫东和豫北地区8月中旬之后成虫量急剧增加,9月中旬出现成虫高峰期。在7月中旬之前,草地贪夜蛾在河南省的为害面积较小,8月份之后,为害面积明显增加,豫中、豫东和豫北地区的为害面积明显比豫南大。在新乡原阳地区抽样调查发现,草地贪夜蛾在晚播玉米上数量较大,常规夏播玉米上数量很少。【结论】采用探照灯诱集法与性信息素诱集法相结合,重点调查晚播玉米田的监测方法,可有效提高草地贪夜蛾监测的敏感性和...     

我国草地贪夜蛾入侵扩张动态与发生趋势预测

草地贪夜蛾是新入侵我国的重大害虫。2019年1月发现其发生后,至7月5日该虫已入侵我国22个省区1 128个县区,危害面积约830万亩。本文根据我国草地贪夜蛾主要入侵事件的参数,应用直线距离法计算出目前我国该虫扩散传播速度为14.03～14.78 km/d;建立了入侵省级区域数量、县级区域数量、入侵危害面积与入侵时间长度关系模型,分别为Y_p=e~((0.4235+0.0156T))、Y_c=e~((2.9857+0.0237T))和Y_s=e~((-2.4312+0.0364T))。根据所建模型预测出2019年7月中旬被入侵的省级区域数量约为30个,7月底入侵县级区域数量将达到2 300多个,9月上旬入侵危害玉米、甘蔗等作物面积达到最大,约为500万ha。以上关于我国草地贪夜蛾长距离传播扩散研究结果将为预防和控制该虫提供参考。     

草地贪夜蛾对玉米和高粱的产卵选择及寄主适合度

【目的】旨在明确草地贪夜蛾Spodopterafrugiperda在玉米和高粱上的产卵选择性和寄主适合度,为草地贪夜蛾的科学防控提供依据。【方法】在室内25℃条件下,采用叶片饲养观察的方法,比较草地贪夜蛾在玉米和高粱上的产卵量、取食量以及食物利用效率,并构建实验种群生命表。【结果】草地贪夜蛾偏好在玉米叶片背面产卵,其平均卵块数最多,达到（3.40±0.55）块,且平均产卵量达到（346.00±72.55）粒。取食玉米的草地贪夜蛾幼虫存活率显著高于取食高粱的（P<0.05）,两者的平均存活率分别为98.89%和86.78%;在取食后5、6和7 d时,取食玉米的草地贪夜蛾幼虫食物利用效率显著高于取食高粱的（P<0.05）;取食玉米的草地贪夜蛾幼虫发育总历期显著短于取食高粱的（P<0.05）;在生命表参数比较中,取食玉米的草地贪夜蛾种群的净增殖率（R0）显著高于取食高粱的（P<0.05）,两者的平均净增殖率分别为（415.93±69.69）和（372.45±34.70）。【结论】草地贪夜蛾在玉米和高粱上均能完成生活史,玉米表现出更高的寄主适合度。但由于草地贪夜蛾在高粱上亦有较高的寄主适合度,且玉米和高粱生育期几近相同,因此在我国西南高粱种植面积较大地区,尤需提前防范草地贪夜蛾从玉米转移至高粱为害的风险。     

不同地区田间草地贪夜蛾卵巢的结构和发育

【目的】探明田间草地贪夜蛾Spodoptera frugiperda卵巢的发育状态及其变化,为草地贪夜蛾种群的发生和迁飞动态提供精准监测依据。【方法】采用雌性生殖系统解剖法,比较不同日龄和地区的田间草地贪夜蛾雌蛾卵巢的形态差异,分析卵巢成熟状态与雌蛾交配的关系。【结果】草地贪夜蛾雌蛾生殖系统包含卵巢、输卵管、交配囊、导精管、受精囊、附腺和产卵器。根据形态特征可以将田间草地贪夜蛾卵细胞分为卵黄发生前期、卵黄期和成熟期3个时期。田间雌蛾1日龄卵巢中发育最快的卵仅处于卵黄期中期,卵巢管柄为空;3日龄卵巢出现分化,一部分卵巢仍然和1日龄相似,另一部分卵巢中存在成熟卵;这种卵巢发育分化到羽化后11 d时仍然存在。云南江城、弥勒,广西田阳以及浙江瑞安和镇海等地的田间雌蛾,到死亡时分别有61.5%, 51.7%, 41.7%, 42.1%和35.5%卵巢发育不成熟。室内饲养第1代雌蛾中,有39.6%的个体到死亡时卵巢未发育成熟,和田间雌蛾比例相似。交配雌蛾卵巢可以是发育成熟和未成熟的,但是未成熟卵巢的比例仅为18.0%±5.0%。【结论】结果提示同一代次的田间草地贪夜蛾可能同时存在迁飞和非迁飞个体,...     

草地贪夜蛾幼虫对四种刺激物质的味觉感受和取食选择

【目的】为了筛选有效的草地贪夜蛾Spodoptera frugiperda幼虫取食激食素和抑制剂并探究其味觉感受机理,为生态防治草地贪夜蛾提供理论和实践上的依据。【方法】利用单感受器记录法测定草地贪夜蛾5龄第2天幼虫下颚外颚叶上中栓锥感器和侧栓锥感器对不同浓度的蔗糖、黑芥子苷、单宁酸和盐酸奎宁4种刺激物质的电生理反应,并采用二项叶碟法测定草地贪夜蛾幼虫对这些刺激物质的取食选择行为。【结果】草地贪夜蛾幼虫中栓锥感器和侧栓锥感器内均存在对蔗糖、黑芥子苷和单宁酸敏感的味觉受体神经元,但是神经元的活性随着刺激物的种类及浓度而变化。其中,两类感器内神经元对蔗糖和黑芥子苷的反应均呈现典型的浓度梯度反应。中栓锥感器内存在对盐酸奎宁敏感的味觉受体神经元,但是呈现逆浓度梯度的反应模式,侧栓锥感器内不存在对盐酸奎宁敏感的神经元。蔗糖显著诱导幼虫的取食行为,而盐酸奎宁、黑芥子苷和单宁酸均抑制幼虫的取食行为,且都呈现浓度梯度的抑制活性。【结论】草地贪夜蛾幼虫中栓锥感器和侧栓锥感器内均存在对取食激食素和抑制剂敏感的味觉受体神经元,但是两类感器不论在反应谱上还是敏感性上均存在差异。蔗糖可以作为取食激食素,盐酸奎宁...     

草地贪夜蛾幼虫对常用杀虫剂相对敏感基线的建立

[目的]本研究旨在建立草地贪夜蛾Spodoptera frugiperda对常用杀虫剂的相对敏感基线,为我国草地贪夜蛾的抗药性系统性监测提供依据.[方法]从玉米田采集草地贪夜蛾在室内不接触任何杀虫剂连续饲养5～7代,采用浸叶法和点滴法测定了草地贪夜蛾3龄幼虫以及采用饲料药膜法测定了草地贪夜蛾2龄幼虫对6大类共7种常用杀...     

Genetic structure and molecular variability of Spodoptera frugiperda (Lepidoptera: Noctuidae) collected in maize and cotton fields in Brazil

The purpose of this research was to evaluate the genetic similarity and structure of the fall armyworm, Spodoptera frugiperda (J.E. Smith), populations associated with maize and cotton crops in Brazil using amplified fragment length polymorphisms. Mean genetic similarity among populations was 0.45. The unweighted pair group method with arithmetic mean analysis dendrograms did not separate populations of S. frugiperda into clusters related to the host plant in which the insects were collected. No genetic variation was observed among maize and cotton populations of S. frugiperda, suggesting that the same populations are injuring both crops in Brazil. This research validates the need for stewardship of crop-protection methods for managing S. frugiperda to reduce the incidence of pesticide resistance, due to the spatial and temporal overlapping of maize and cotton crops in some regions in Brazil.     

草地贪夜蛾在不同小麦品种上的取食选择性和适应性及其与叶片生化物质含量的关系

[目的]测定草地贪夜蛾Spodoptera frugiperda在不同小麦品种上的取食选择性及适应性,探索害虫为害与小麦品种间的关系,明确黄淮海麦区主栽小麦品种对草地贪夜蛾的抗性水平,为麦田抗虫品种布局和害虫综合防治提供理论依据.[方法]比较了草地贪夜蛾1和3龄幼虫对15个小麦品种的取食选择性,初步筛选出1和3龄幼虫取...     

Ultralow rates of spinosad in phagostimulant granules provide control of Spodoptera frugiperda (Lepidoptera: Noctuidae) in maize

Field trails in 2002 and 2003 were performed to determine the efficacy of maize flour-based granular formulations with ultralow rates of the naturally derived insecticide spinosad (0.1, 0.3, and 1.0 g [AI]/ha), for control of Spodoptera frugiperda (J.E. Smith) in maize, Zea mays L., in southern Mexico. Spinosad formulations were compared with a chemical standard, a commercial granular formulation of chlorpyrifos (150 g [AI]/ha). In both years, application of spinosad resulted in excellent levels of control, indicated by the number of living S. frugiperda larvae recovered from experimental plots. The efficacy of spinosad applied at 0.3 and 1.0 g (AI)/ha was very similar to that of chlorpyrifos. Natural reinfestation caused S. frugiperda numbers in insecticide treated plots to return to values similar to the control treatmentby 10-15d postapplication. Many spinosad-intoxicated larvae collected in the field died later in the laboratory in 2002, but not in 2003. Percentage mortality due to parasitoid emergence did not differ in any treatment in either field trial. The number of parasitoids that emerged from S. frugiperda collected in each treatment was significantly reduced after application of spinosad (all rates) or chlorpyrifos due to a reduction in the number of host larvae. Parasitoid numbers returned to control values by 9-15 d postapplication in all treatments. The most prevalent parasitoid was the braconid Chelonus insularis Cresson, which represented approximately 80% of emerging parasitoids in both years. We conclude that appropriate formulation technology can greatly enhance the performance of this naturally derived, biorational insecticide.     

Microbiome of the larvae of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) from maize plants

Fall armyworm (FAW), Spodoptera frugiperda, is an invasive insect pest with a diverse host range threatening food security in the African continent by causing severe economic damage to staple maize crop. FAW like all other insects are associated with various microbiota that influence their several characteristics and activities. The microbiota of insects plays important roles in their growth, development and environmental adaptation to their host plants or animals and not much is known about microbiota of FAW in Nigeria. In this study, the microbial community of FAW larvae from maize plants in Nigeria was investigated using Illumina PE250 NovaSeq of 16S rRNA V3-V4 gene region. A total of 1,160,133 sequence reads that ranged from 83,794 to 145,475 were obtained. They span through 2 kingdoms: bacteria (99.59%) and archaea (0.37%), 37 phyla, 59 classes, 78 orders, 145 families and 285 genera. The dominant taxonomic group of bacteria across the larval samples were Proteobacteria (58.32%), Firmicutes (35.87%) and Bacteroidetes (4.02%). There were no significant differences in bacteria species diversity and richness among the individual fall armyworm larva and samples from different geographical regions. The relative abundance of Bacteria phyla and classes also showed no significant differences among the larval samples. Significant differences were documented in bacteria orders Acidobacteriales and Aeromonadales, family Acidobacteriaceae_ (Subgroup_1) and genera Novosphingobium and Pedobacter. The results indicate that the gut of FAW larvae harbours a diverse set of bacteria and archaea biota. Understanding their ecological and functional relevance would provide novel insight on potential approaches for their exploitation in the integrated management of FAW in the tropics.     

我国草地贪夜蛾田间种群有机磷和氨基甲酸酯类杀虫剂靶标基因ace-1的基因型和突变频率

【目的】对入侵我国的草地贪夜蛾Spodoptera frugiperda有机磷和氨基甲酸酯类杀虫剂靶标基因ace-1的基因型进行分子检测,明确抗性基因频率,进而指导田间科学用药。【方法】采集中国12省份的草地贪夜蛾田间种群幼虫样本,提取单头样本的基因组DNA,利用特异性引物进行PCR扩增,获得ace-1基因片段。根据碱基、氨基酸序列比对和测序峰图分析,明确与有机磷和氨基甲酸酯类杀虫剂抗性相关的3个氨基酸突变位点A201S, G227A和F290V的基因型和抗性基因频率。【结果】通过DNA检测分析中国12省份草地贪夜蛾田间种群589头个体ace-1基因的基因型和突变频率发现,在A201S位点检测到137头个体为抗性杂合基因型,抗性基因频率为11.6%,未发现抗性纯合基因型个体;G227A位点589头个体均为敏感纯合基因型;F290V位点的抗性基因频率最高,达到57.1%,携带抗性基因的个体数量达到523头(占样本总数的88.8%)。【结论】结果表明入侵我国的草地贪夜蛾种群携带高频率的对有机磷和氨基甲酸酯类杀虫剂抗性基因。田间防治建议不用或少用有机磷和氨基甲酸酯类杀虫剂,同时进一步加强田间...     

基于性诱和深度学习的草地贪夜蛾成虫自动识别计数方法

[目的]探究深度学习在草地贪夜蛾Spodoptera frugiperda成虫自动识别计数上的可行性,并评估模型的识别计数准确率,为害虫机器智能监测提供图像识别与计数方法.[方法]设计一种基于性诱的害虫图像监测装置,定时自动采集诱捕到的草地贪夜蛾成虫图像,结合采集船形诱捕器粘虫板上草地贪夜蛾成虫图像,构建数据集;应用Y...     

Oil-soluble dyes for marking Spodoptera frugiperda (Lepidoptera: Noctuidae)

Although various biological aspects of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) have been examined, adult movement and dispersal of this insect pest is not well understood. Release-recapture techniques by using marked insects is a useful approach for dispersal studies; however, the marking technique should not significantly affect insect biology or behavior. Therefore, the effect of different concentrations of oil-soluble dyes (Solvent Blue 35 [C.I. 61554], Sudan Red 7B [C.I. 26050], Sudan Black B [26150], Sudan Orange G [C.I. 11920], and Sudan I 103624 [C.I. 12055]) on development, mortality, and fecundity of S. frugiperda was evaluated. Dyes were added to artificial diet used to feed larvae. Larval and pupal development and mortality, adult longevity, and female fecundity were evaluated. High concentrations (400 and 600 ppm) of all dyes led to longer larval and pupal stages. Adult life span and number of eggs were not affected by the dyes. Sudan Red 7B marked both adults and eggs very well. Solvent Blue 35 marked both adults and eggs, but the blue-marked eggs could not be distinguished from some bluish eggs laid by nonlabeled females. Adults and eggs were not adequately marked by the Sudan Black B, Sudan Orange G, and Sudan I 103624 (a yellow dye).