In plants, one of the most sophisticated defensive strategies against herbivores is producing toxic metabolites for protecting themselves. 2-Tridecanone, which has been identified as a plant-derived and herbivore-induced defensive substance of plants, plays a role in retarding the development and decreasing the survival rate of Lepidopteran larvae. In the present study, we comprehensively evaluated the overall toxic effects of 2-tridecanone on the oriental armyworm, Mythimna separata Walker, 1851 (Lepidoptera: Noctuidae), a notorious polyphagous pest. Our results revealed that 2-tridecanone at a sublethal concentration for the second-instar significantly delayed larval development, lowered the body weight of larvae and pupae, decreased the pupation and emergency rates, reduced the mating rate of adults, and impaired the fecundity of female moths. Notably, the fecundity and net reproductive rate (R0) of the F1 generation in the 2-tridecanone treatments were also reduced, indicating that the effects of 2-tridecanone are transgenerational in M. separata population. Our findings demonstrate the direct and long-term influence of 2-tridecanone on pests, and contribute the development of sustainable and eco-friendly pest management strategies.

The cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a major pest in cotton production, notorious for its rapid development of resistance to pesticides, which complicates control efforts. A sustainable solution involves combining selective insecticides with biocontrol agents to reduce pest populations while preserving natural enemies. Afidopyropen, a novel transient receptor potential vanilloid-targeted insecticide, was extremely safe for the minute pirate bug Orius sauteri Poppius (Hemiptera: Anthocoridae), a common predator of small pests. The LC50 values for direct exposure were 592.38, 497.02, and 382.71 mg/L for the fifth instars and female and male adults, respectively. Even at the maximum recommended field rate, afidopyropen had minimal impact on the survival, predation efficiency, and reproduction of pesticide-treated O. sauteri and their offspring. Despite the resistance observed in field-collected A. gossypii, combining a low concentration of afidopyropen with O. sauteri significantly reduced aphid populations. By day 7 post-treatment, aphid density was decreased by over 94.29%. While a higher concentration of afidopyropen initially achieved 98.19% control, aphid populations rebounded over time. This study demonstrated that afidopyropen was extremely safe for O. sauteri as indicated by the higher LC50 values. The combination of a low concentration of afidopyropen with O. sauteri offers an effective control approach for resistant A. gossypii, presenting a novel integrated pest management strategy.

Sex pheromones, which play a critical role in mediating sexual communication of Lepidoptera, are biosynthesized by a variety of particular enzymes in specialized pheromone glands (PGs). Among these enzymes, fatty acyl-CoA reductases (FARs) catalyze the reduction of fatty acyl precursors to their corresponding alcohols. In this study, we identified 32 FARs from the genome of Mythimna loreyi, an important agricultural pest. Among all MlorFARs identified, only MlorFAR1 showed a PG expression pattern and exhibited a positive response to pheromone biosynthesis activating neuropeptide (PBAN) injection. Silencing MlorFAR1 reduced pheromone titers by 70.4-88.9% and significantly reduced mating rates at the 48-72 h postinjection time point. Heterologous expression in yeast confirmed that MlorFAR1 preferentially converted medium-chain fatty acid methyl esters to alcohols. These findings establish MlorFAR1 as a pivotal enzyme in the biosynthesis of sex pheromones in M. loreyi, providing a framework for the development of innovative pest management strategies.

In moths, sex pheromones are synthesized in pheromone glands (PGs) by a variety of enzymes. Desaturases (DESs) are critical for the introduction of double bonds into pheromones. In Mythimna loreyi, the specific DESs involved in sex pheromone biosynthesis remain unclear. In this study, we identified and characterized 25 putative DESs from the M. loreyi genome. Nineteen of them were expressed in the female PGs, with seven showing significant upregulation in response to pheromone biosynthesis activating neuropeptide (PBAN). RNAi-based knockdown of MlorDES2 significantly reduced the titer of pheromone components by 58.6-85.9%, while knockdown of MlorDES9 specifically reduced the production of (Z)-9-tetradecenyl acetate. Functional verification in yeast revealed that MlorDES2 and MlorDES9 exhibited Δ11 and Δ9 desaturase activities, respectively. Taken together, these results collectively demonstrate that MlorDES2 and MlorDES9 are involved in sex pheromone biosynthesis of M. loreyi, suggesting that DESs could be used as potential targets for pest management.

Quantitative real-time PCR (qRT-PCR) is widely accepted as a precise and convenient method for quantitatively analyzing the expression of functional genes. The data normalization strongly depends upon stable reference genes. The bean bug, Riptortus pedestris (Hemiptera: Alydidae), is a significant pest of leguminous crops and broadly distributed across Southeast Asia. In this study, a total of 16 candidate reference genes (RPL32, RPS23, SDHA, UBQ, UCCR, GST, TATA−box, HSP70, GAPDH, RPL7A, SOD, RPS3, Actin, α−tubulin, AK, and EF1) were carefully chosen in R. pedestris, and their expression levels were assessed across various conditions, including different developmental stages, diverse tissues, temperature treatments, adult age, molting time, and mating status. Following this, the stability of these reference genes was evaluated using four algorithms (ΔCt, GeNorm, NormFinder, and BestKeeper). Ultimately, the comprehensive rankings were determined using the online tool RefFinder. Our results demonstrate that the reference gene for qRT-PCR analysis in R. pedestris is contingent upon the specific experimental conditions. RPL7A and EF1 are optimal reference genes for developmental stages. Furthermore, α−tubulin and EF1 exhibit the most stable expression across various adult tissues. RPL32 and RPL7A exhibit the most stable expression for adult age. For nymph age, RPL32 and SOD display the most stable expression. For temperature conditions, RPS23 and RPL7A were identified as the most suitable for monitoring gene expression. Lastly, we verified the practicability of evaluating expression levels of odorant-binding protein 37 (RpedOBP37) and cytochrome P450 6a2 (RpedCYP6) throughout developmental stages, tissues, and temperature conditions. These findings are a significant addition to the qRT-PCR analysis studies on R. pedestris, serving as a fundamental groundwork for future investigations on stable reference genes in R. pedestris as well as other organisms.

劳氏粘虫Mythimna loreyi是粘虫Mythimna seperata的近缘种,两者在形态上相近,为害特征基本相同,但在不同地区的发生危害规律可能存在一定差异.近些年来,劳氏粘虫在许多国家和地区频繁暴发危害,已成为一种普遍发生的农业害虫.为今后深入研究劳氏粘虫的暴发成灾规律和综合防控技术,本文在分析国内外研究资料的基础上,对劳氏粘虫的研究进展进行了综述.目前,劳氏粘虫已分布于亚洲、欧洲、非洲、大洋洲和北美洲的近80个国家和地区.以幼虫取食危害玉米、水稻和小麦等多种禾本科作物和杂草;3龄前幼虫食量小,5-6龄幼虫食量增大,进入暴食期.幼虫具有聚集性、杂食性和暴食性,成虫具有迁飞性,发生危害时具有隐蔽性、偶发性和暴发性.劳氏粘虫的发生和为害规律常因地区、年份和季节的不同而存在差异.气候条件、食物和天敌是影响劳氏粘虫发生危害的主要因素,而气候因素、人类活动和害虫的生物学特征是导致近些年来劳氏粘虫发生范围扩大,危害程度加重的重要原因.性诱剂、天敌和生物农药是近些年来劳氏粘虫生物防治研究的主要方向.根据目前劳氏粘虫在我国的发生情况及研究现状,我们建议今后从以下3个方面开展工作:(1)借鉴粘虫的防控策略和防治经验,从空中和地面两个方面加强预测预报工作,建立和完善预测预报系统;(2)从农业防治、物理防治、生物防治和化学防治等方面开展综合防治工作;(3)将生物技术和现代农业信息技术等现代化的技术和方法应用于暴发成灾规律和综合防治研究中,并建立综合防控技术系统.

Interspecies competition affects the distribution, quantity, and community structure of insects, especially among closely-related (congeners) species. Some ecological factors differentially affect the fitness of co-existing species, thus conferring an advantage on one competitor, and then the structure of communities. The present work evaluated the effects of high temperature and natural enemies on the interspecific competition between the grain aphid Sitobion miscanthi (Takahashi) (Aphididae: Hemiptera) and bird cherry-oat aphid Rhopalosiphum padi (L.) (Hemiptera: Aphididae), two key pests of wheat in China. Results showed that the population growth of R. padi was faster at 30°C, and the intrinsic rate of natural increase (rm) value was 5 times that of S. miscanthi, indicating that R. padi was more high-temperature resistant and has advantages in interspecific competition at high temperature. Moreover, compared to S. miscanthi, the population of R. padi was less affected by their predator, larvae of the multicolored Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), and aphid parasitoids, Aphidius avenae (Haliday) or Aphidius gifuensis (Ashmead) (Hymenoptera: Aphidiidae), which made them gain an advantage in the interspecific competition. Our results enrich the knowledge of phytophagous insect interspecific completion and implicate the ecological mechanism of R. padi may become the dominant species in wheat fields in China.

为了解河南信阳黏虫的发生情况,本研究利用高空探照灯对2016年-2019年黏虫成虫的种群动态进行了监测及分析.结果表明,2016年-2019年在河南信阳监测的黏虫成虫主要为东方黏虫(又称为黏虫)和劳氏黏虫,均一年发生5代,整个监测期间均出现多个高峰期.其中,东方黏虫以一代为主,占全年总诱虫量的54.62％～82.96％,并且大部分虫源向外迁出,少部分留在本地;劳氏黏虫以三代或四代为主,以留在本地或迁入为主,只有少数向外迁出.本研究为河南省信阳地区黏虫的预测预报和防控提供了参考.

The orange wheat blossom midge Sitodiplosis mosellana Gehin (Diptera: Cecidomyiidae), an economically important pest, has caused serious yield losses in most wheat-growing areas worldwide in the past half-century. A high-quality chromosome-level genome for S. mosellana was assembled using PacBio long read, Illumina short read, and Hi-C sequencing technologies. The final genome assembly was 180.69 Mb, with contig and scaffold N50 sizes of 998.71 kb and 44.56 Mb, respectively. Hi-C scaffolding reliably anchored 4 pseudochromosomes, accounting for 99.67% of the assembled genome. In total, 12,269 protein-coding genes were predicted, of which 91% were functionally annotated. Phylogenetic analysis indicated that S. mosellana and its close relative, the swede midge Contarinia nasturtii, diverged about 32.7 MYA. The S. mosellana genome showed high chromosomal synteny with the genome of Drosophila melanogaster and Anopheles gambiae. The key gene families involved in the detoxification of plant secondary chemistry were analyzed. The high-quality S. mosellana genome data will provide an invaluable resource for research in a broad range of areas, including the biology, ecology, genetics, and evolution of midges, as well as insect-plant interactions and coevolution.

为了解黏虫和劳氏黏虫在河南原阳的发生情况,本研究利用佳多虫情测报灯对2015年-2019年两种害虫成虫的种群动态进行了监测,并对两者的发生动态进行了比较分析.结果表明,2015年-2019年间在河南原阳监测的黏虫和劳氏黏虫成虫均发生4代.两种成虫在原阳的发生规律存在明显差异,其中,黏虫以第一代为主,占全年总诱虫量的55.4％～93.6％,主要发生期在5月下旬至6月上旬;劳氏黏虫以第三代为主,占全年总诱虫量的54.4％～87.8％,主要发生期在9月下旬至10月上旬.本研究为河南省原阳地区黏虫和劳氏黏虫的预测预报和防控提供了参考.

Barometric pressure is an important factor influencing several insect traits. Most studies have been conducted on the behavior of insects in relation to rapid and slight changes in pressure magnitudes or short-term pressure trends, but there is little information on the effect of long-term and large pressure variations on insect traits. Here, we assessed the effects of static low barometric pressure on the tethered flight, lifespan and reproductive performance of Mythimna separata (Walker), a long-distance migratory insect, using an apparatus simulating low barometric pressure at altitudes of 500 m above sea level. We found that both the flight distance and flight duration of M. separata moths were significantly longer under low barometric pressure conditions. Exposure to low barometric pressure conditions for 24 and 48 h significantly shortened the lifespan of female moths but had no influence on male moths. The ovaries of female moths developed earlier, and the preoviposition and oviposition periods were significantly shortened under low atmospheric pressure. Moreover, low atmospheric pressure reduced the respiration rate of female moths. However, there was an increase in the respiration rate of female moths after being returned to standard barometric pressure conditions. Our results show that the behavior and physiological traits of insects are affected by the low-pressure environment during migration. The low barometric pressure conditions at high altitudes is one of important factors accelerating reproductive behavior of M. separata after migration.

为阐明黄光光照强度对甜菜夜蛾Spodoptera exigua Hübner成虫生殖行为和寿命的影响.本研究设置3个光照强度(1 Lx,10 Lx,100 Lx)和一个对照(CK)处理,观察记录不同处理下甜菜夜蛾的单雌产卵量、产卵前期、产卵期、卵孵化率及成虫寿命.结果表明,黄光不同光照强度对甜菜夜蛾的生殖行为和雌成虫寿命均存在不同程度的影响,在光照强度达到10 Lx和100 Lx的情况下,其单雌产卵量明显降低,产卵历期和雌成虫寿命明显缩短,当光照强度为1 Lx情况下与对照相比无明显差异.该研究结论为防蛾灯的进一步优化和完善提供了一定的理论支撑.

瘿蚊科是双翅目昆虫中的重要类群.本研究对瘿蚊科3种昆虫 麦红吸浆虫、菊花瘿蚊和食蚜瘿蚊的核糖体DNA进行PCR扩增、克隆、测序及序列分析,并对ITS-1在麦红吸浆虫4个地理种群中的遗传变异情况进行分析.结果 表明,从3种昆虫中获得的核糖体DNA序列包括:部分的18S rDNA(44 bp)、28S rDNA(37 bp),全部的ITS-1(487～535 bp),5.8S rDNA(121 bp)及ITS-2(336～352 bp)序列.3种昆虫ITS序列的碱基差异百分比在17.21％～29.59％之间,共含有206个变异位点.ITS-1序列在麦红吸浆虫4个地理种群中比较保守,只有4个变异位点,单倍型多样性为0.311 7～0.796 5,核苷酸多样性为0.000 6～0.002 2.本研究为今后瘿蚊科昆虫的分类鉴定、系统发育和遗传进化等相关研究提供了基础.

东亚小花蝽Orius sauteri是一种重要的捕食性天敌,为了加快东亚小花蝽商品化进程,本研究评价了以粘虫Mythimna separata卵作为东亚小花蝽替代饲料的饲养效率.结果 表明,东亚小花蝽取食粘虫卵可以完成其正常的生长发育,东亚小花蝽成虫获得率为77.5％,平均单雌产卵量为72.5粒.在食物充足的情况下,雌性东亚小花蝽世代取食总量为80.4粒.以上结果对东亚小花蝽的规模化饲养和害虫绿色防控具有重要的技术支撑和应用前景.

草地贪夜蛾Spodoptera frugiperda又称秋黏虫,属鳞翅目Lepidoptera夜蛾科Noctuidae灰翅夜蛾属Spodoptera,原产于美洲热带和亚热带地区(Todd & Poole,1980).该虫翻殖能力强、扩散速度快,近年来已在全球多个国家迅速蔓延,成为威胁农业生产的重要害虫之一.防蛾灯是利用昆虫复眼对绿-黄光敏感,而植物对绿-黄光不敏感的特性研制而成的,波长范围在500～590nm,其通过干扰蛾类昆虫的日节律,起到控制蛾类种群发展的目的(蒋月丽等,2018).Shimoda & Honda(2013)证实防蛾灯对多种蛾类昆虫具有明显的防控效果.蒋月丽等(2018)也发现黄光和绿光对棉铃虫Helicoverpa armigera等多种蛾类的产卵和成虫寿命有明显的干扰效果.目前尚未见防蛾灯对草地贪夜蛾干扰效果的报道,因此,本研究在室内利用黄、绿光照射对草地贪夜蛾产卵情况、卵孵化率及成虫寿命的影响进行调查和分析,以期了解防蛾灯对草地贪夜蛾的干扰效果,为利用防蛾灯进行田间防控提供理论依据.