Morphological traits for sex identification of the oriental armyworm,Mythimna separata(Lepidoptera:Noctuidae)

The oriental armyworm, Mythimna separata(Lepidoptera:Noctuidae) is a harmful pest which causes heavy loss in agricultural crops. Sex identification of M. separata is very important for understanding the biology and management of this pest. Development of fast and convenient methods to identify M. separata female and male is the necessary prerequisite for conducting gender-related studies. In this study, new methods to differentiate sex of M. separata at pupal and adult stages were investigated. Our results showed that posterior abdominal segments containing genital organs which are morphological traits to differentiate female and male. Genital openings are important characters for the female and male pupae differentiation. For female pupa, it locates on the ventral side of eighth and ninth abdominal segments and appears as a visible longitudinal suture; for male pupa, it locates on the ventral side of the ninth abdominal segment and appears as a short slit surrounded by a pair of visible semicircular lumps. Bristle numbers are another indicator for sex differentiation of adults. Each female has three-bristled frenulum and each male has one bristled-frenulum near the base of hind wing of each side of moth body. We confirmed the two sex differentiation methods manually by dissecting genitalia of adults and found their genger was as same as what we examined the sex of pupae and adults using the morphological methods.     

Effects of constant and stage-specific-alternating temperature on the survival,development and reproduction of the oriental armyworm,Mythimna separata (Walker) (Lepidoptera: Noctuidae)

Migratory insects make diverse adaptive strategies in response to changes in external environment. Temperature has an impact on the survival, development, reproduction, and migration initiation of insects. Previous research has primarily been focused on the effects of constant temperature on populations, but changing temperature has received less attention. Three constant temperature treatments(20, 25 and 30°C) and three pupal-alternating temperature treatments(20–25, 25–20 and 25–30°C) were set up to study the relationship between temperature and population development by age-stage, two-sex life table analysis in the oriental armyworm, Mythimna separata Walker, a notorious migratory pest in grain crops. The 25°C treatment was considered optimal with 20 and 30°C as low suitable temperature and high temperatures, respectively. The survival rate was relatively low before third instar larvae at 20°C(63.0%) and 20–25°C(70.1%), and extreme low after pupal stage at 30°C(20.6%). Developmental duration of each stage was negatively correlated with temperature. The adult preoviposition period, when most migratory insects initiate migration, was the shortest at 25°C(2.69d) but was lengthened at both low suitable(7.48d for 20°C, 6.91d for 25–20°C and 4.57d for 20–25°C) and high temperatures(3.74d for 25–30°C and 5.00d for 30°C). Both low suitable and high temperature decreased lifetime fecundity, net reproductive rate and the intrinsic rate of increase, with variability observed across developmental duration and stage during non-optimal temperature. The results expand knowledge of the relationship between changing temperature and armyworm population development, and adaptive strategies in complex ambient environment.     

蝴蝶蜜源与非蜜源植物挥发物成分的差异

采用全自动热脱附-气相色谱/质谱(ATD-GC/MS)联用技术,对动态顶空密闭循环吸附捕集的蝴蝶蜜源植物马缨丹、马利筋及非蜜源植物缅栀子花的挥发物进行分析检测.结果表明,同为蝴蝶的蜜源植物,马利筋和马缨丹的挥发物成分的种类和含量都有差异.马缨丹的香气成分主要为萜烯类化合物(60%),而马利筋中醛类(33.72%)含量相...     

Analysis on the migration of first-generation Mythimna separata (Walker) in China in 2013

Mythimna separata (Walker) is an important pest which can cause serious damages to cereal crops. In the past two decades, several heavy outbreaks have taken place in northern China. In order to develop a fine-scale method of forecasting outbreaks, population data were collected in northern China using searchlight traps and ground light traps. A background weather pattern analysis and trajectory analysis were performed via the Weather Research and Forecast (WRF) and FLEXPART models. Our results showed that heavy migration of first-generation M. separata appeared in northern China in 2013. In Yanqing District, Beijing, the cumulative number of captured adults in searchlight traps was around 250 000 and the daily maximum for trapped moths was 86 000. During the peak period, the majority of M. separata moths arrived after 00:00 every night. The sex ratio (female:male) at each monitoring site was greater than 1 and greatly fluctuated with population dynamics. During the migration peak, prevailing downdraft winds benefited M. separata moths to land passively. Trajectory simulation showed that immigrants were from Anhui, Jiangsu and Hubei provinces and most of them could continue to fly into the northeastern regions of China. These results provide technical support for fine-scale forecasting of the outbreak of M. separata at meso- and micro-scale.     

云南粘虫的预测预报研究

 粘虫(Mythimna separata Walker)是云南粮食作物的重要害虫之一。1年内有4次危害:a.1～2月在海拔1600m以下,越冬代粘虫危害玉米、小麦、黄豆和绿肥;b.4～5月,海拔1300～2000m范围内,1代粘虫危害小麦;c.6～7月,海拔1000～3200m地区,2代粘虫危害水稻、玉米、陆稻、小麦、青棵和燕麦等;d.8～9月,海拔1000m以下,3代粘虫危害晚稻。一般来说,4～5月麦子正处于成熟期,故云南对1代粘虫往往不予防治。因此,仅对越冬代、2代和3代粘虫的预测预报技术进行了研究。为了提高粘虫的预测预报水平和适时防治其危害,试将越冬代、2代和3代粘虫发生趋势的回归统计预测预报研究予以总结。为方便有关生产单位应用这些研究结果,所有的回归预测式均已编制成计算机程序。     

中国夜蛾科优夜蛾属(鳞翅目:夜蛾科)新记录

记述了中国优夜蛾属Ugia Walker新增一中国新记录种.提供了阳优夜蛾Ugia sundana、紫优夜蛾Ugia purpurea雄性成虫和外生殖器,以及紫优夜蛾Ugia purpurea翅脉图.     

Regularity of population occurrence and migration in the oriental armyworm,Mythimna separata (Walker)

正The oriental armyworm,Mythimna separata(Walker)(Lepidoptera:Noctuidae),is a major migrant pest of grain in China and other Asian countries,causing huge crop production and economic losses nationwide annually.Much of the uniquely difficult aspects of managing M.separata arises from its long-distance migratory behavior.For example,direction and timing of winds from its overwintering regions in the south largely determine where and when large influxes of migrants arrive in the north to oviposit,making prediction of infestations difficult.Since the 1960s,the migration routes and infestation patterns of M.separata in China have been     

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。     

Insecticide resistance of the field populations of oriental armyworm,Mythimna separata (Walker) in Shaanxi and Shanxi provinces of China

Resistance of five field populations of Mythimna separata(Walker) collected from Shaanxi and Shanxi provinces of China to six different insecticides was evaluated by leaf dip method in the laboratory. The results showed that all populations were relatively sensitive to emamectin benzoate with a resistance ratio(RR) of 0.583–1.583 folds. All populations showed susceptible or low level resistance to chlorantraniliprole and beta-cypermethrin. Compared with a relatively susceptible strain of M. separata, the resistance level of the whole populations ranged from susceptible to moderate to chlorpyrifos and lambda-cyhalothrin, moderate to high to phoxim(RR=19.367–70.100) except for population from Sanyuan County(RR=2.567). Pair-wise correlation analysis among different insecticides indicated that chlorpyrifos has a significantly positive and significant correlation with emamectin benzoate. Chlorantraniliprole didn't have significant correlation with emamectin benzoate, chlorpyrifos and phoxim. Therefore, emamectin benzoate, chlorantraniliprole and beta-cypermethrin are recommended to control oriental armyworm. Meanwhile, to postpone the occurrence and development of insecticide resistance in Shaanxi and Shanxi provinces, alternative and rotational application of insecticides between chlorantraniliprole and emamectin benzoate or chlorpyrifos is necessary.     

夜蛾科(鳞翅目)2中国新记录种记述

通过对西藏自治区林芝市色季拉山昆虫调查,发现2个中国新记录种:玉藏夜蛾(Himalistra rubida Hreblay,PlanteRonkay,1995)、黑须璃杆夜蛾(Hyalobole nigripalpis(Warren,1911))。对所研究的种类外部形态和外生殖器特征做了描述,给出了成虫和外生殖器照片及分布。     

人工饲料饲养草地贪夜蛾的生长发育与繁殖

目的筛选对草地贪夜蛾(Spodoptera frugiperda)毒力较高的白僵菌(Beauveria)菌株,为草地贪夜蛾的生态防控提供真菌资源储备;通过球孢白僵菌(B. bassiana)的田间调查,为了解农田生态系统中白僵菌的自然发生状况奠定基础。方法用爬行接种法测定来自保山市、怒江州和大理州的10种共计15株白僵菌菌株对草地贪夜蛾3龄幼虫的毒力,并分析保山市4种农田生态系统(咖啡园、茶园、玉米田和烟田)中球孢白僵菌的月间消长动态。结果15株白僵菌对草地贪夜蛾的毒力有差异,毒力最低的菌株致死率仅为10%,毒力较强的9株菌株致死率达100%;但这9株菌株的致死速度不同,全致死时间为4.4~15.7 d,半致死时间(LT₅₀)为2.3~10.3 d,其中毒力最强的菌株为来自保山潞江坝怒江江边沙滩的菌株BUB12 (全致死时间=4.4 d,LT₅₀=2.3 d),其次为来自保山腾冲烟田的菌株BUB8 (全致死时间=5.8 d,LT₅₀=2.5 d)。4种农田土壤中全年均有球孢白僵菌分布,夏季检出菌株最多;多年生作物农田(茶园和咖啡园)中白僵菌的数量高于一年生作物农田(玉米田和烟田)。结论白僵菌菌株BUB12和BUB8对草地贪夜蛾的毒杀效果最好,具有较大的应用潜力。     

重大入侵害虫草地贪夜蛾发生危害、防控研究进展及防控策略探讨

目的评价芦荟精油对茚虫威防治草地贪夜蛾(Spodoptera frugiperda)的增效作用,以期为草地贪夜蛾的防治提供理论基础。方法以表面张力、扩展直径、最大持留量、室内毒力和田间防效为评价指标,测定添加0.05%芦荟精油对茚虫威药液物理性状、室内毒力及田间防效的影响。结果添加芦荟精油后,药剂表面张力由51.30~67.57 mN/m减小到34.43~51.60 mN/m;扩展直径由1.33~1.98 mm增大到1.69~2.93 mm;持留量由2.86~3.25 mg/cm²增大到3.34~4.65 mg/cm²。芦荟精油对茚虫威防治草地贪夜蛾室内毒力增效比介于7.20%~19.61%,田间防效增效比介于3.82%~26.93%。结论芦荟精油可通过降低药液表面张力、增大药液扩展直径和提高药液持留量,对茚虫威防治草地贪夜蛾具有较好的增效作用。     

食料与培养条件对川西北高原粘虫幼虫生长发育的影响

以8种不同科属植物的幼叶、成熟叶、花序为食料,在4种培养条件下饲喂粘虫幼虫,测定幼虫存活率、存活时间、虫龄持续时间、幼虫期长度、采食量等指标,结果表明:食料科属是决定存活率与存活时间的主要因素;幼虫1~2龄持续时间间差异极显著,3龄间差异显著,4~6龄间差异不明显;食料科属、食料部位、培养条件及各因素互作都极显著影响幼虫期长度与采食量(P<0.0001<0.01);温度比光照周期更影响幼虫存活时间,光照时间比温度更影响幼虫期长度与采食量。     

吉林省粘虫种群发生动态及其危害控制技术

根据吉林省粘虫发生危害期的部分田间调查结果、春季应用糖醋酒诱蛾剂获得的地面测蛾量的数据及吉林省各地一代、二代粘虫发生危害的记录,阐述了近20年吉林省粘虫发生的种群动态及为控制粘虫危害所采取的预测预报与防治措施,提出了控制粘虫危害急需改进的技术建议。     

中国赭夜蛾属一新记录种(鳞翅目:夜蛾科)

报道了夜蛾科赭夜蛾属Carea Walker中国一新记录种,即Carea subangulata Kobes,1997．该种在外部形态上与C．angulata 和C．parangulata很相似,但很容易从雄虫外生殖器上区分,编制了赭夜蛾属Carea Walker在中国已知种的检索表。     

Effect of a near-zero magnetic field on development and flight of oriental armyworm(Mythimna separata)

The geomagnetic field affects all living organisms on the Earth. In this study we investigated the developmental and behavioral effects of rearing Mythimna separata in a near-zero magnetic field(500 n T) compared to the local geomagnetic field(approximately 50 μT). The near-zero magnetic field produced by a Helmholtz coil system significantly lengthened larval and pupal development durations, increased male longevity, and reduced pupal weight, female reproduction, and the relative expression level of the vitellogenin(Vg) gene in newly emerged females. Moreover, the near-zero magnetic field had a considerable negative effect on the mating ratio of M. separata adults. In addition, the moths in the near-zero magnetic field displayed less flight activity late in the night than those in the Earth's normal geomagnetic field, indicating that the flight rhythm of M. separata may be affected by the near-zero magnetic field. Reduction in magnetic field intensity may have negative effects on the development and flight of oriental armyworm, with consequent additional effects on its migration.     

黔西南州薏苡粘虫的危害习性及其气象影响因素

[目的]了解黔西南州薏苡粘虫的危害习性。[方法]于2015年在黔西南州安龙县对薏苡粘虫进行蛾量、田间卵量、幼虫密度和气象因子影响等的调查。[结果]粘虫对薏苡的危害以第2代为主,6月中下旬为危害盛期,暴雨对粘虫有抑制作用。[结论]调查结果为下一步制定薏苡粘虫的防治措施提供了理论依据。     

杂夜蛾亚科2种幼虫形态记述（鳞翅目：夜蛾科）

详细记述了中国甜菜夜蛾Spodoptera exigua（Hübner） 和稻蛀茎夜蛾Seasamia inferens （Walker） 幼虫的形态特征,并提供了形态特征图。图2参9     

广州地区一株绿僵菌的鉴定及其对草地贪夜蛾的致病力测定

[目的]寻找草地贪夜蛾(Spodoptera frugiperda)致病性昆虫病原真菌,以丰富广东省本地的昆虫病原真菌资源库,为开展草地贪夜蛾微生物防治提供研究材料.[方法]对采自广东省广州市增城区荔城镇玉米地的感菌草地贪夜蛾幼虫体表病原真菌进行微生物常规分离纯化,采用形态学和ITS-rDNA序列分析相结合的方法对病原真菌进行鉴定,通过3种不同培养基(PDA、SMAY和添加草地贪夜蛾蛹壳PDA培养基)测定病原真菌菌落生长速率和产孢量,并采用浸虫法研究病原真菌对草地贪夜蛾2龄幼虫的致病力.[结果]从感菌草地贪夜蛾幼虫上分离获得病原真菌,编号GZSF-1,经鉴定为莱氏绿僵菌(Metarhizium rileyi).培养基类型对菌株GZSF-1菌丝生长和产孢存在显著影响(P<0.05),菌株在各培养基上的生长速率为0.76~2.10 mm/d,产孢量为0.33×106~21.67×106孢子/mL,其中在添加蛹壳PDA培养基上的生长速度最快且可获得最大产孢量.菌株GZSF-1接种草地贪夜蛾2龄幼虫后,随孢子悬浮液浓度的升高,幼虫的感病死亡率增加,当浓度达1×109孢子/mL时,幼虫的致死中时(LT50)为3.030 d,接菌7 d后幼虫的累计校正死亡率达100.00%.应用Probit模型,得到菌株GZSF-1对草地贪夜蛾2龄幼虫的致病力回归方程y=-4.426+0.737x,菌株GZSF-1对草地贪夜蛾2龄幼虫第7 d的致死中浓度(LC50)为1.02×106孢子/mL.[结论]从田间感菌草地贪夜蛾上分离获得的病原真菌菌株GZSF-1为莱氏绿僵菌,该菌株对草地贪夜蛾幼虫具有较好的生防潜力,具有进一步研究的价值.