Analysis of the spatiotemporal trends and influencing factors of Hyphantria cunea in China

In recent years,the situation of the Hyphantria cunea(Drury)(Lepidoptera:Erebidae),infestation in China has been serious and has a tendency to continue to spread.A comprehensive analysis was carried out to examine the spa-tial distribution trends and influencing factors of H.cunea.This analysis involved integrating administrative division and boundary data,distribution data of H.cunea,and envi-ronmental variables for 2021.GeoDetector and gravity analysis techniques were employed for data processing and interpretation.The results show that H.cunea exhibited high aggregation patterns in 2021 and 2022 concentrated mainly in eastern China.During these years,the focal point of the infestation was in Shandong Province with a spread towards the northeast.Conditions such as high vegetation density in eastern China provided favorable situations for growth and development of H.cunea.In China,the spatial distribution of the moth is primarily influenced by two critical factors:precipitation during the driest month and elevation.These play a pivotal role in determining the spread of the species.Based on these results,suggestions are provided for a mul-tifaceted approach to prevention and control of H.cunea infestation.

Reproduction and biological characteristic of Chouioia cunea

Chouioia cunea Yang is a natural enemy for many kinds of crop and forest pests, particularly for Hyphantria cunea Drary, which is an international quarantine pest. The experiment of rearing Chouioia cunea with Tussah (Silkworm) pupa were carried out by 搕hree-cut method?and inoculating method. The results showed that three-cut method is effective way for breed-ing Chouioia cunea, with a parasitical rate of 95%. The biological characteristics and the life cycle of Chouioia cunea were ob-served and described and more hosts of Chouioia cunea were found. 揟hree-cut method?as a new technique of rearing Chouioia cunea has been put into practice.

Cadmium(Cd)exposure through Hyphantria cunea pupae reduces the parasitic fitness of Chouioia cunea:A potential risk to its biocontrol efficiency

Heavy metal contamination has been regarded as an environmental variable that affects the efficiency of pest biological control,but the parasitic fitness of parasitoids under heavy metal stress is poorly understood.Herein,the effect of Cd exposure through the host pupa of Hyphantria cunea on the parasitic fitness of Chouioia cunea was investigated,and the mechanism by which Cd exposure affects the interaction between H.cunea and C.cunea from the perspective of innate immunity in host insect and the oxidative status in the parasitoid offspring was explored.Our results indicated that Cd can be transferred from the H.cunea pupae to the parasitoid offspring,and the transfer coefficient reflected biological amplification.There were no significant differences in the rates of parasitism success and offspring emergence between the untreated and Cd-treated groups.However,after parasitizing Cd-accumulated pupae,the parasitic fitness of offspring wasps(e.g.,the number,individual size and life span)decreased significantly.Under Cd exposure,the cellular and humoral immunity of H.cunea pupae decreased significantly.Compared with the untreated group,the H_(2)O_(2)content of parasitoid offspring in the Cd-treated group was significantly increased.Cd exposure significantly inhibited superoxide dismutase activity in parasitoid offspring,but the contents of ascorbic acid and glutathione were significantly increased by Cd stress.Taken together,these results indicate that Cd exposure reduces the cyclic utilization efficiency of C.cunea on H.cunea pupae.The oxidative status of parasitoid offspring triggered by Cd exposure could be responsible for the reduced parasitic fitness of C.cunea on Cd-accumulated H.cunea pupae.

白蛾周氏啮小蜂Chouioia cunea Yang的研究和生物防治应用进展

白蛾周氏啮小蜂Chouioia cunea是世界性检疫对象——美国白蛾Hyphantria cunea的重要蛹期寄生性天敌,对控制美国白蛾的危害起到重要作用。自该蜂发现以来,围绕白蛾周氏啮小蜂的生物学特性和人工繁育技术等关键问题,开展了大量工作,证实其具有寄生率高、繁殖力强、雌性比大等优点,为一种优良的寄生蜂。特别是在该蜂的应用方面,目前已经摸索出一套成体系的白蛾周氏啮小蜂种蜂繁育技术和林间释放技术,在各发生区均获得良好的防治效果。但在基础研究方面还需进一步深入开展相关工作,如在寄主识别与标记,作用于寄主的寄生因子及其对寄主发育的影响,寄生行为的分子生物学机制等方面还需开展系统的研究工作,为该蜂的人工繁育质量及林(田)间有效保护和利用提供理论指导。

美国白蛾Hyphantria cunea(Drury)越冬蛹的抗寒性研究

基于为控制美国白蛾Hyphantria cunea(Drury)对桑树和柞树的的危害提供理论依据,测定了美国白蛾越冬蛹不同时期的过冷却点和含水量。结果显示,越冬蛹的过冷却点以2月份最低,为(-27.07±0.38)℃,11、12月份最高,分别为(-20.38±2.26)℃和(-22.99±4.03)℃;含水量以11、3月最高,分别为67.03%和65.07%,1月份开始下降,2月份降至最低30.76%,3月份又增加到45.95%。含水量的变化与过冷却点的变化趋势相似,含水量的下降降低了越冬蛹的过冷却点,可增强其抗寒能力。

A Facile Synthetic Method for (3Z,6Z,9S,10R)-9,10-Epoxy-3,6-heneicosadiene,Sex Pheromone Component of Hyphantria Cunea (Drug)

Total synthesis of (3Z, 6Z, 9S, 10R)-9, 10-epoxy-3, 6-heneicosadiene, sex pheromone component of Hyphantria cunea (Drug), was achieved using Sharpless AE kinetic resolution and alkylative epoxide rearrangement as key steps.

The eff ects of temperature and host size on the development of Brachymeria lasus parasitising Hyphantria cunea

Brachymeria lasus Walker is a solitary endoparasitoid that attacks the pupae of a wide range of lepidopteran hosts,including an important invasive species,the fall webworm(Hyphantria cunea Drury).We studied the relationship between temperature and development of B.lasus from egg to adult hatching.The results show a decrease in parasitoid development time from 34.4 days at 18°C to 10.6 days at 32°C.The minimum threshold temperature of B.lasus was 13.2°C±1.7°C,and the eff ective accumulated temperature was 210.3±28.7 degree days.These results provide a basis for optimizing the production of this parasitoid.In addition,the eff ects of host size on off spring performance of B.lasus were investigated under laboratory conditions.Off spring longevity,size,and percentage of females were positively correlated with host size.Female off spring are larger and live longer than males.Furthermore,this research showed that parasitoid adults successfully emerged from approximately 27.9%of pupae.However,eclosion or hatching of H.cunea decreased dramatically,which may be due to damage caused by female B.lasus when testing hosts with their ovipositors or by feeding on them.The results suggest that B.lasus has the potential to become an effi cient natural enemy for controlling H.cunea.

AFLP analysis of genetic variation of Hyphantria cunea(Drury) populations in Beijing and a nearby site

Hyphantria cunea （Drury） is a severe invasive pest in Beijing. It is important to understand the reason for its successful invasion and outbreak. Accordingly, this study was tailored to assess molecular variation and genetic relationships among three H. cunea populations in Beijing and one population from Sanhe in Hebei Province as control （totally 100 individuals）. A silver-labeled amplified fragment length polymorphisms （AFLP） DNA profiling method was used to detect the genetic diversity and relationship among the populations. Five EcoRI and MseI primer combinations produced a total of 171 （91.2% polymorphic） informative fragments. The average Nei＇s genetic diversity in four H. cunea populations analyzed by Popgene3.2 software was 0.2287, and the level of genetic diversity ranked in the order BDR （reared population in Daxing, Beijing） 〉 BDN （natural population in Daxing, Beijing） 〉 HSN （natural population in Sanhe, Hebei Province） 〉 BFN （natural population in Fengtai, Beijing）. The value of genetic differentia- tion among populations was 0.3321, and the gene flow was 1.0057. The genetic distance between these populations ranged from 0.0735 to 0.3309, 0.0531 on average. The result of UPGMA （unweighed pair group method with arithmetic averages） clustering showed that populations BFN and HSN were closely related, while BFN and BDN had the largest genetic distance. These results indicate that H. cunea populations in Beijing might originate from several areas.

Effects of Some Materials Extracted from Ajuga Species on the Larvae of Hyphantria cunea and its Natural Enemies

Six kinds of cxtracts drawn from Ajuga multiflora and .A. multliflora var. brevispicala and A. multiflora var.serotina using methanol and acetone were used in this experiment to test their killing activity to the second instar larvae ofHypantria cunea and their influence on its natural enemics. The average death rate caused by those extracts on the secondinstar larvae was 85.70%. The mortality rate caused by the extracts drawn with methanol was from 88.89% to 96.33%,which was significal1tly l1igl1er tl1a11 tl1at caused by acetol1e extracts. 'I11osc extracts were satt to TrchogranInIa `Ie)uI,xiIinIi,Coccinella septempunctata, the natural enelnies of H. cunea. We did not found any evidence shown that those extracts hadany influence the emergence and the devclopment of T. dendrolimi. Those methanolic extracts gotten from A. multiflora andA. multiflora var. brevispicata had no significant effects on the mortality of the larvae and adults of C. septenrpunctala.Those eXtracts could be used in the control of H cunea sattly.

Growth simulation of Fraxinus chinensis stands damaged by Hyphandria cunea in Beijing area

Hyphandria cunea is an insect that can damage hundreds of plants in its larval phase and needs to be placed under quarantine at an international level. Its hosts involve 600 plant species, including forest and fruit trees, shrubs, crops, vegetables, weeds and others. In 2006, we surveyed two Fraxinus chinensis Roxb stands, damaged to different degrees, after the invasion of H. cunea in the Changping district of the Beijing area. Given our survey of individual trees and investigation of bio-environmental factors, we pro-vide a preliminarily simulation of the growth situation of F. chinensis stands, damaged by H. cunea, by using the Forest Vegetation Simulator software （FVS）, which is supported by the ＂948＂ project from the State Forestry Administration of China. The results will provide a valuable reference in forecasting the effect of H. cunea and other invasive pests in China on forest ecological values.

白蛾周氏啮小蜂(Chouioia cunea Yang)毒器官的超微结构观察

为明确白蛾周氏啮小蜂(Chouioia cunea Yang)毒器官的超微结构和毒器官的功能,本研究利用显微解剖技术解剖周氏啮小蜂毒器官并使用倒置显微镜观察其外部形态,随后将毒器官经固定、脱水、浸透、包埋后采用超薄切片技术进行切片,切片经染色、脱色后利用透射电镜观察了周氏啮小蜂毒器官的超微结构。结果表明:周氏啮小蜂毒器官由一个毒囊和一条毒腺构成,证实周氏啮小蜂毒腺含有大量分泌细胞,其中细胞器有细胞核、分泌囊泡、线粒体、自噬小体、末端附器及末端微绒毛。同时还观察到,周氏啮小蜂毒囊由肌肉鞘层、上皮细胞层和内膜层组成,肌肉鞘层中肌纤维规则地排列且不交错,上皮细胞层细胞器稀少,内膜层呈波浪状加厚。因此,周氏啮小蜂毒腺中的细胞器决定其具有强大的分泌功能,但由于没有液泡等细胞器而不具备贮存毒液的功能。周氏啮小蜂毒囊中空且细胞器稀少,毒腺分泌的毒液贮存于毒囊中,且在周氏啮小蜂产卵时因肌肉鞘层中肌纤维的收缩注入寄主体内。

Genetic diversity and differentiation of fall webworm (Hyphantria cunea Drury) populations

The molecular variation and genetic relationships among five populations of the fall webworm （Hyphantria cunea Drury） in China were assessed using microsatellite technology. Ten microsatellite primers, producing polymorphic bands, were used across 300 samples. The percentage of polymorphic loci （PPB） was 98.36%; the percentage of polymorphic loci in five populations ranged from high to low in the following order： Cangzhou population, Yantai population, Qinhuangdao population, Dandong population, and Shijiazhuang population. The results showed that 34.38% of the total genetic variation of the fall webworm （GsT） occurs among populations, while most variation （65.62%） exists within populations. Nei＇s genetic distances ranged from 0.1386 to 0.3224. Using the unweighted pair group method with arithmetic mean （UPGMA）, Nei＇s genetic distances were analyzed by a clustering technique and the dendrogram shows that population differentiation is closely related to the time and geographic origin of the invasion. The major factors impacting genetic diversity of fall webworm populations are longitude, the plain area ratio, annual precipitation, latitude and time of invasion. The formation of genetic structure is correlated with characteristics of the life history and invasion ecology of the species.

Masculinizer gene controls sexual differentiation in Hyphantria cunea

The Masculinizer gene,Masc,encodes a lepidopteran-specific novel CCCHtype zinc finger protein,which controls sex determination and dosage compensation in Bombyx mori.Considering the potential application of it in pest control,it is necessary to investigate the function of Masc gene in Hyphantria cunea,a globally invasive forest pest.In the present study,we identified and functionally characterized the Masc gene,HcMasc,in H.cunea.Sequence analysis revealed that HcMASC contained the conserved CCCH-type zinc finger domain,nuclear localization signal,and male determining domain,in which the last was confirmed to be required for its masculinization in BmN cell line.However,expression data showed that unlike male-biased expression in B.mori,Hc-Masc gene expresses in main all developmental stages or tissues in both sexes.Clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9-based disruption of the common exons 1 and 3 of the HcMasc gene resulted in imbalanced sex ratio and abnormal external genitalia of both sexes.Our results suggest that the HcMasc gene is required for both male and female sexual differentiation and dosage compensation in H.cunea and provide a foundation for developing better strategies to control this pest.

Steroid hormone 20-hydroxyecdysone disturbs fat body lipid metabolism and negatively regulates gluconeogenesis in Hyphantria cunea larvae

The steroid hormone 20-hydroxyecdysone(20E)has been described to regulate fat body lipid metabolism in insects,but its accurate regulatory mechanism,especially the crosstalk between 20E-induced lipid metabolism and gluconeogenesis remains largely unclear.Here,we specially investigated the effect of 20E on lipid metabolism and gluconeogenesis in the fat body of Hyphantria cunea larvae,a notorious pest in forestry.Lipidomics analysis showed that a total of 1907 lipid species were identified in the fat body of H.cunea larvae assigned to 6 groups and 48 lipid classes.The differentially abundant lipids analysis showed a significant difference between 20E-treated and control samples,indicating that 20E caused a remarkable alteration of lipidomics profiles in the fat body of H.cunea larvae.Further studies demonstrated that 20E accelerated fatty acidβ-oxidation,inhibited lipid synthesis,and promoted lipolysis.Meanwhile,the activities of pyruvate carboxylase,phosphoenolpyruvate carboxykinase,fructose-1,6-bisphosphatase,and glucose-6-phosphatase were dramatically suppressed by 20E in the fat body of H.cunea larvae.As well,the transcriptions of genes encoding these 4 rate-limiting gluconeogenic enzymes were significantly downregulated in the fat body of H.cunea larvae after treatment with 20E.Taken together,our results revealed that 20E disturbed fat body lipid homeostasis,accelerated fatty acidβ-oxidation and promoted lipolysis,but negatively regulated gluconeogenesis in H.cunea larvae.The findings might provide a new insight into hormonal regulation of glucose and lipid metabolism in insect fat body.

Effects of 4-hexylresorcinol on the phenoloxidase from Hyphantria cunea （Lepidoptera： Arctiidae）： In vivo and in vitro studies

Insecticidal effects of 4-hexylresorcinol, a phenoloxidase （PO） inhibitor, were determined on Hyphantria cunea （Drury） under laboratory conditions. The LC50 for the 15- d-old larvae was estimated to be 2.95 g/L after 96 h exposure. The activities of glutathione S-transferase （GST） and PO showed a decrease in larvae treated with 4-hexylresorcinol, and the IC50 of GST and PO were estimated to be 0.8 and 0.43 g/L, respectively, 24 h after treatment. The PO from the hemolymph of fall webworm was purified by ammonium sulfate precipitation, gel-filtration, and ion-exchange chromatography, and then enzymatic characteristics and the mechanism of inhibition were determined using L-dihydroxyphenylalanine （L-DOPA） as the substrate. The purified PO showed a single band on SDS-PAGE with a molecular weight of about 70 kDa. The optimum pH for PO activity was observed at pH 7.0, optimum temperature was found to be 45 ℃, and PO activity was strongly inhibited by Zn2＋. IC50 values were estimated to be 8.2, 19.14, and 24.04/zmol/L for 4-hexylresorsinol, kojic acid, and quercetin, respectively. The inhibitory potencies （i.e., 150 of each compound/Is0 of 4-hexylresorcinol） ofkojic acid and quercetin on H. cunea PO were estimated to be 1.87 and 2.89, respectively. 4-hexylresorcinol was determined to be a competitive inhibitor, and kojic acid and quercetin were determined to be mixed inhibitors. PO is one of the most important enzymes in an insect＇s immune system, and the use ofPO inhibitors seems to be a promising approach for pest control due to their potential safety for humans.

Identification and field evaluation of the sex pheromone of an invasive pest,the fall webworm Hyphantria cunea in China

Pheromone gland extracts of the fall webworm,Hyphantria cunea(Lepidoptera:Arctiidae) were analyzed by gas chromatography(GC) and gas chromatography-mass spectrometry(GC-MS).Based on comparison of retention times and mass spectra of synthetic standards,four compounds were identi-fied as(9Z,12Z)-octadecadienal,(9Z,12Z,15Z)-octadecatrienal,(3Z,6Z,9S,10R)-9,10-epoxy-3,6-heneicosadiene and(3Z,6Z,9S,10R)-9,10-epoxy-1,3,6-heneicosatriene with a ratio of 2:33.6:58.4:6.Trapping tests showed that quaternary blend of these compounds was highly attractive to male H.cunea.Unitraps baited with the quaternary blend loading of 200―300 μg on a gray rubber septum were very effective for monitoring H.cunea populations.

Electroantennogram responses of an invasive species fall webworm(Hyphantria cunea) to host volatile compounds

Electroantennogram responses of fall webworms(Hyphantria cunea) to 55 host volatile compounds were conducted.Results showed that male moths were more responsive to trans-2-hexenyl acetate,nonanal,hexanal,trans-2-hexenal,hexanol,isoamyl acetate,acetic acid cis-3-hexenyl ester,ethyl acetoacetate,citronellal and(+)-citronellal,and females were more responsive to hexanol,hexanal,acetophenone,isoamyl acetate,nonanal,trans-2-hexenal,acetic acid cis-3-hexenyl ester,citronellal,cis-3-hexen1-ol and trans-2-hexen-1-ol.Seven bioactive compounds were also selected for further dosage response experiments,and a positive correlation was found between the fall webworm and the tested compounds.A maximum dosage level of 1000 g was tested and found to elicit significantly higher activity from male moths compared with lower(1,10,100 g) concentrations.

5种植物源杀虫剂对美国白蛾的田间药效评价

[目的]明确5种植物源杀虫剂对美国白蛾的田间防效及最适药剂用量。[方法]采用喷雾处理对美国白蛾盛发前期三龄幼虫进行田间防效试验。[结果]1.2%烟碱·苦参碱乳油6、8、12 mg/L对美国白蛾的防治效果最好,药后3 d为87.83%~92.61%,药后14 d防效达到最高,为95.85%~97.99%。1.5%苦参碱可溶液剂、0.5%虫菊·苦参碱可溶液剂药后14 d防效达到最佳,分别为84.62%~95.13%、89.14%~91.93%。[结论]1.2%烟碱·苦参碱乳油推荐有效成分含量6~12 mg/L对美国白蛾盛发前期三龄幼虫的防治效果最好,可大面积推广使用。0.5%虫菊·苦参碱可溶液剂和1.5%苦参碱可溶液剂在防治时也可进行交替使用,对杨树生长、有益天敌种类和数量无不良影响。

美国白蛾天敌昆虫应用研究进展

美国白蛾是一种国际检疫性害虫,原产于北美。由于美国白蛾强大的扩散能力、较长的为害期以及快速繁殖等特性,目前已有35个国家报道了其入侵记录。自1979年美国白蛾在辽宁丹东发现以来,不断地向我国南方地区扩散。因此,根除全部种群已不可能,采取持续有效的生物防控策略是可行的途径。本文总结了国内外美国白蛾的捕食性和寄生性天敌种类,比较了不同地区和不同发生期美国白蛾天敌的多样性,并对利用本地天敌和引进原产地天敌防治美国白蛾的应用技术进行了归纳分析。原产地天敌对美国白蛾具有更强的适应性和攻击性,通过引进原产地天敌可望实现更加持续有效的控制作用。最后展望了天敌昆虫控制美国白蛾的应用前景。

美国白蛾RyR对氯虫苯甲酰胺胁迫响应及分子对接分析

【目的】阐明美国白蛾鱼尼丁受体(RyR)如何参与氯虫苯甲酰胺对美国白蛾的毒杀作用,并探究RyR与氯虫苯甲酰胺的分子对接模式,以期揭示美国白蛾RyR基因响应氯虫苯甲酰胺胁迫的分子机制。【方法】克隆获得美国白蛾RyR基因的完整cDNA序列,采用实时荧光定量RT-PCR技术分析RyR基因的时空表达模式以及在亚致死质量浓度氯虫苯甲酰胺胁迫下美国白蛾RyR基因的表达水平。通过RNAi技术沉默美国白蛾RyR基因,进而测定沉默体在氯虫苯甲酰胺胁迫下的存活率,探讨美国白蛾RyR基因对氯虫苯甲酰胺抗性的调控作用。利用Discovery Studio 2019 Client软件对氯虫苯甲酰胺与RyR受体进行分子对接,并通过结合能和可视化分析对接情况。【结果】(1)氯虫苯甲酰胺对美国白蛾3龄幼虫72 h的致死中质量浓度(LC50)和亚致死质量浓度(LC30)分别为21.40、11.13μg/L,显示出较高的生物活性。(2)在氯虫苯甲酰胺LC30质量浓度(11.13μg/L)处理下,美国白蛾3龄幼虫RyR基因的相对表达量随处理时间的延长表现为先升高后降低,处理48和72 h分别为对照组的2.6倍和1.5倍。(3)HcRyR基因沉默体在氯虫苯甲酰胺LC30胁迫下72 h时存活率为73.33%,显著高于对照组的46.66%,表明沉默RyR基因显著降低了美国白蛾3龄幼虫对氯虫苯甲酰胺的敏感性。(4)分子对接结果表明RyR与氯虫苯甲酰胺的结合能为-31.35 kJ/mol,两者间存在氢键与范德华力使其稳定结合。【结论】明确美国白蛾RyR基因对氯虫苯甲酰胺胁迫响应分子机制,为进一步认识美国白蛾RyR结构,并为靶向杀虫剂开发提供理论依据。