A mite parasitoid,Pyemotes zhonghuajia,negatively impacts the fitness traits and immune response of the fall armyworm,Spodoptera frugiperda

Parasitoids are key regulators in ecological communities and widely used as agents in biocontrol programmes.The fall armyworm,Spodoptera frugiperda,recently invaded multiple continents and caused substantial economic losses in agriculture.Pyemotes zhonghuajia,a newly identified mite parasitoid,has shown potential for controlling various agricultural insect pests.Therefore,this study tested the performance of P.zhonghuajia in parasitising S.frugiperda.We also investigated the sublethal effects of parasitism by P.zhonghuajia on host fitness traits,transgenerational impacts,and cellular and humoral immunity.Our result showed that the fifth-instar larvae of S.frugiperda parasitised by 40 P.zhonghuajia were all dead(i.e.,a lethal effect),while parasitism by 5 or 10 P.zhonghuajia was considered sublethal since many S.frugiperda survived to adulthood and produced offspring after mating.The sublethal influences from parasitism by P.zhonghuajia resulted in reduced pupal weight,adult emergence rate and fecundity,but increased developmental time and longevity.Parasitism at both lethal(40 mites)and sublethal(10 mites)levels impaired the cellular and humoral immunity of S.frugiperda.This study presents the first empirical evidence that mite parasitoids can negatively influence host immunity.Moreover,it provides insights into the biocontrol potential of mite parasitoids and their interactions with hosts.

Tissue distribution of cadmium and its effect on reproduction in Spodoptera exigua

Vegetable fields are often contaminated by heavy metals,and Spodoptera exigua is a major vegetable pest which is stressed by heavy metals mainly by feeding.In this study,cadmium accumulation in the tissues of S.exigua exposed to cadmium and its effects on the growth and development of the parents and the offspring were investigated.Under the stress of different concentrations of cadmium(0.2,3.2,and 51.2 mg kg^(-1)),the cadmium content in each tissue of S.exigua increased in a dose-dependent manner.At the larval stage,the highest cadmium accumulation was found in midgut in all three cadmium treatments,but at the adult stage,the highest cadmium content was found in fat body.In addition,the cadmium content in ovaries was much higher than in testes.When F1S.exigua was stressed by cadmium and the F_(2)generation was not fed a cadmium-containing diet,the larval survival,pupation rate,emergence rate and fecundity of the F_(2)generation were significantly reduced in the 51.2 mg kg^(-1)treatment compared to the corresponding F1generation.Even in the F_(2)generation of the 3.2 mg kg^(-1)treatment,the fecundity was significantly lower than in the parental generation.The fecundity of the only-female stressed treatment was significantly lower than that of the only-male stressed treatment at the 3.2 and 51.2 mg kg^(-1)cadmium exposure levels.When only mothers were stressed at the larval stage,the fecundity of the F_(2)generation was significantly lower than that of the F1generation in the 51.2 mg kg^(-1)treatment,and it was also significantly lower than in the 3.2 and 0.2 mg kg^(-1)treatments.The results of our study can provide useful information for forecasting the population increase trends under different heavy metal stress conditions and for the reliable environmental risk assessment of heavy metal pollution.

Induced CTL-S15 gene expression by Bacillus thuringiensis declines susceptibility in Spodoptera exigua

It has been reported that C-type lectins(CTLs),which are pattern recognition receptors of the insect innate immunity response,may compete with Cry toxin for the receptor alkaline phosphatase to decrease its toxicity in insects.However,to date,which CTLs affect larval susceptibility to Bt in Spodoptera exigua is not clear.In this study,33 CTL genes were identified from S.exigua.Based on the number of carbohydrate-recognition domains(CRDs)and the domain architectures,they were classified into three groups:(1)nineteen CTL-S(single-CRD),(2)eight immulectin(dual-CRD)and(3)six CTL-X(CRD with other domains).RT-qPCR analysis revealed that expression levels of SeCTL-S15,IML-4 and CTL-X6 were upregulated after challenge with Bt and Cry1Ab.Tissue and developmental stage expression analysis showed that only SeCTL-S15 was mainly expressed in the midgut and larva,respectively.Knockdown of SeCTL-S15 significantly increased Bt susceptibility,as indicated by reduced survival and larval weight.These results suggest that CTL-S15 might play a vital role in the low susceptibility of larvae to Bt in S.exigua.Our results provide new insights into CTL function in insects.

Identification of transient receptor potential channel genes and functional characterization of TRPA1 in Spodoptera frugiperda

Spodoptera frugiperda is a highly destructive pest that has become a global problem due to its robust reproductive and migratory capabilities.Transient receptor potential(TRP)channels,which constitute a vast ion channel family,play pivotal roles in sensing the external environment and maintaining internal homeostasis in insects.TRP channels have been widely investigated for their critical roles in regulating various insect behaviors in recent years.In this study,we identified 15 TRP gene loci encoding 26 transcripts in the genome of S.frugiperda and analyzed their expression profiles at different developmental stages.The results revealed that S.frugiperda possesses four TRPC genes,six TRPA genes,one TRPM gene,two TRPV genes,one TRPN gene,and one TRPML gene,while a canonical TRPP is absent.Moreover,the SfruTRPA1 was functionally characterized using the Xenopus oocyte expression system.The results showed that SfruTRPA1 is activated by temperature increases from 20 to 45℃,and there is no significant desensitization after repeated stimuli within the same temperature range.Additionally,SfruTRPA1 is activated by certain natural chemicals,including allyl isothiocyanate(AITC)and cinnamaldehyde(CA).These findings provide valuable insights to the TRP genes in S.frugiperda.

Seasonal Dynamic of the Fall Armyworm, Spodoptera frugiperda (J.E Smith, 1797) (Lepidoptera: Noctuidae) on Maize Crop in the Sub-Sudanese Zone of Côte d’Ivoire

In Côte d’Ivoire, maize (Zea mays L) is the second most cultivated cereal after rice. Since the first report of Spodoptera frugiperda in Côte d’Ivoire, maize production in the northern regions has been affected resulting in maize production losses. This study aims to study the seasonal dynamic of Spodoptera frugiperda in maize fields in the sub-Sudanese zone, main zone of maize cultivation in Côte d’Ivoire. The study was done using pheromone trap lures. The results revealed a variation in the moth population at various growth stages during rainy and dry seasons. Notably, the highest numbers of moths were consistently trapped during the whorl stage with counts ranging from 131 ± 35.7 during the rainy season to 70.6 ± 15.01 in the dry season. The lowest numbers of moths were observed during pod maturation, with counts ranging from 30.3 ± 13.05 during the rainy season to 11.7 ± 3.05 in the dry season. Between the 7th and 21st days after sowing, the count of moths displayed a consistent upward trajectory, reaching 188 moths during the rainy season. The damages were particularly observed at whorl stage. The relationship between the numbers of moths and some climatic variables revealed a negative correlation between moths numbers and rainfall (r= −0.44) and relative humidity (r= −0.684). In contrast, there were positive relationships with temperature (r = 0.16), highlighting the significant impact of temperature changes on moth population dynamics. The research highlights the need for integrated pest management strategies that consider climatic factors and growth stages of maize to mitigate the impact of this insect pest on maize.

Accurate recognition of the reproductive development status and prediction of oviposition fecundity in Spodoptera frugiperda(Lepidoptera:Noctuidae)based on computer vision

Spodoptera frugiperda(Lepidoptera:Noctuidae)is an important migratory agricultural pest worldwide,which has invaded many countries in the Old World since 2016 and now poses a serious threat to world food security.The present monitoring and early warning strategies for the fall army worm(FAW)mainly focus on adult population density,but lack an information technology platform for precisely forecasting the reproductive dynamics of the adults.In this study,to identify the developmental status of the adults,we first utilized female ovarian images to extract and screen five features combined with the support vector machine(SVM)classifier and employed male testes images to obtain the testis circular features.Then,we established models for the relationship between oviposition dynamics and the developmental time of adult reproductive organs using laboratory tests.The results show that the accuracy of female ovary development stage determination reached 91%.The mean standard error(MSE)between the actual and predicted values of the ovarian developmental time was 0.2431,and the mean error rate between the actual and predicted values of the daily oviposition quantity was 12.38%.The error rate for the recognition of testis diameter was 3.25%,and the predicted and actual values of the testis developmental time in males had an MSE of 0.7734.A WeChat applet for identifying the reproductive developmental state and predicting reproduction of S.frugiperda was developed by integrating the above research results,and it is now available for use by anyone involved in plant protection.This study developed an automated method for accurately forecasting the reproductive dynamics of S.frugiperda populations,which can be helpful for the construction of a population monitoring and early warning system for use by both professional experts and local people at the county level.

Mutagenesis of odorant coreceptor Orco reveals the distinct role of olfaction between sexes in Spodoptera frugiperda

Odorant receptor(OR)is crucial for insects to detect and recognize external chemical cues closely related to their survival.The insect OR forms a heteromeric complex composed of a ligand-specific receptor and a ubiquitously odorant receptor coreceptor(Orco).This study used the CRISPR/Cas9 technique to knock out(KO)Orco and reveal its essential role in acting on OR-meditated olfactory behavior in a critical invasive agricultural pest,the fall armyworm(FAW),Spodoptera frugiperda.Electroantennogram(EAG)results suggested that the Orco mutants of both male and female moths severely reduced their electrophysiological responses to the eight tested plant volatiles and two sex pheromones.However,the Orco gene played distinct roles in mating behavior between sexes:the mating behavior was fully disrupted in mutated males but not in mutated females.The oviposition result indicated that the Orco KO females displayed reduced egg laying by 24.1%compared with the mated wild type(WT)females.Overall,these results strongly suggest that Orco is an excellent target for disrupting FAW’s normal behavior and provides a feasible pest control approach.

Inventory of Host Plants and Parasitoids of the Fall Armyworm (FAW), Spodoptera frugiperda (JE Smith), in the Southern Agricultural Zone of Niger

The fall armyworm, Spodoptera frugiperda (JE Smith), is a polyphagous pest reported in sub-Saharan Africa since 2016 and has expanded rapidly in almost Africa. In Niger, Spodoptera frugiperda (JE Smith) is considered like a major pest of maize, to which it causes significant damage, in a context where proven control methods against this moth remain almost non-existent. The objective of the present study was to determine the economic importance of FAW through the damage caused to the different host plants and to identify the parasitoids of this caterpillar. The study was conducted in the southern agricultural zone of Niger, specifically in the regions of Dosso, Maradi, Tahoua and Zinder. FAW eggs and caterpillars were collected from six villages in each region and then incubated and reared in the entomology laboratory of INRAN in Maradi. The rate of infestation of the different crops by FAW was determined as well as the observation of the beneficiaries. The results obtained indicate the presence of FAW on millet with an attack rate varying from 45.7% to 68%, sorghum with 47.2% to 62.25% and sesame with 9.7%. This work also revealed an oophagous parasitoid, Telenomus remus with 138 ± 23 and larval parasitoids, Cotesia sp with 16 ± 1 maximum number of individuals emerged from the collected material. Also, it was identified the parasitoid Cotesia icipe with a rate of parasitism from 4.6% to 5.75%;the Charops ater whose rate of parasitism varies from 4.5% and 12.25% but for Chelonus insularis with 17.25% and Tachnidae with 53%. These very interesting results will constitute a basis for the development of biological control and a component of an agroecological management strategy of caterpillar.

Occurrence Characteristics and Prevention and Control Measures of Spodoptera frugiperda in Maize

Based on practical work experience,this paper analyzed the occurrence characteristics and control measures of Spodoptera frugiperda in maize.The measures including forecasting and early warning,regional prevention and control,agricultural prevention and control,physical prevention and control,chemical prevention and control,and biological prevention and control can effectively control the damage of S.frugiperda and guarantee the safety of food production.The results will provide some reference for the prevention and control of S.frugiperda.

Preliminary Study of Predation Effectiveness of the Assassin Bug Rhynocoris rapax Stal (Heteroptra: Reduviidae) on Fall Armyworm Spodoptera frugiperda Smith (Lepidoptera: Noctuidae), a Major Pest of Maize Crops

Maize is a staple food in many sub-Saharan African countries, grown on large surfaces and with high production. However, maize’s cultivation is often confronted with attacks by the fall armyworm, which considerably reduces production. Thus, the use of biological agents in the control of the fall armyworm would contribute effectively to the sustainability of agriculture. It is in this context that this study, conducted at the La Mé station of the National Centre for Agronomy Research, aims to test the effectiveness of Rhynocoris rapax, a powerful predator of various insect families, on the fall armyworm Spodoptera frugiperda, for biological control of this maize pest in Côte d’Ivoire. Therefore, 3 batches of 1 adult individuals of Rhynocoris rapax were captured in trial plots set up at the La Mé station. These individuals were then put in contact with 3 batches of 5, 20 and 40 larvae of the pest in rearing boxes at an average temperature of 26.4°C and an average relative humidity of 60%, in order to evaluate the efficiency of the predation. The results showed that Rhynocoris rapax kills more larvae when these are in large numbers. The mortality of the high number of larvae was observed during the first three days, probably due to the voracity and aggressiveness of Rhynocoris rapax that period. So R. rapax is a potential predator of fall armyworm and should be protected.

Perception and Management Strategies of the Fall Armyworm, Spodoptera frugiperda J.E. Smith (1797) (Lepidoptera: Noctuidae) on Maize, Millet and Sorghum by Farmers in Western Burkina Faso

Since it was first detected in Africa in early 2016, the fall armyworm (FAW), Spodoptera frugiperda Smith (Lepidoptera: Noctuidae), has spread to over 50 African countries, including Burkina Faso. This insect pest attacks important cereals, such as maize, millet and sorghum, which are the staple food in Burkina Faso. Since the invasion of the FAW in Africa, data on farmers’ knowledge and their perceptions of this insect’s pest are scarce and fragmented in Burkina Faso. Although this issue has been already addressed in some African countries, farmers’ perceptions of this invasive insect pest may differ from one country to another. This reality justifies our study, the main objective of which is to assess the perception and level of knowledge of farmers on this new invasive insect pest and the consequences of its damage to cereal production in western Burkina Faso. To do this, a stratified survey was conducted among 355 farmers in two important agricultural regions of Burkina Faso, namely the Hauts-Bassins and the Cascades. At the end of these surveys, it was found that the age of the people surveyed varied from 18 to 80 years. People between the ages of 41 and 50 and 31 and 40 were the most numerous, with 31.27% and 30.14% of the target population, respectively. In addition, the majority of the farmers were male, 94.08% of them being men and 5.92% being women. More than half (50.42%) of this population was non-literate. Almost all of the farmers surveyed (97.46%) said they had heard of S. frugiperda and 80.85% of them said they could identify the insect pest. The date of appearance of the FAW was variously perceived by the farmers of the study area. According to these cereals growers, the years 2016, 2017, 2018, and 2019 were to be remembered in terms of the insect pest’s appearance. While for sorghum and millet the change in yields from 2010 to 2019 seemed slight, it was quite remarkable for maize according to the farmers. The average maize yield in 2016 and 2017 was 1.95 and 1.83 t/ha, respectively. These values will increase slightly in 2018 and 2019 with 2.08 and 2.39 t/ha, respectively. In the field, several management methods were used by the farmers to control the insect pest’s attacks. These include chemical, cultural, and physical control. Insecticide spray frequencies ranged from 1 to 4 and even more depending on the duration of the maize cycle.

Insect Resistance of Different Tissues of Transgenic Cotton to Spodoptera exigua(Hbner)

[Objective] The aim was to learn the resistance of different tissues and organs of transgenic cotton to Spodoptera exigua （Hbner）. [Method] Flowers,the 1st,the 3rd,the 6th and the 14th leaves from the top of 33B,GK12 and SGK321 were used to feed S. exigua neonates respectively. Survival larvae and dead ones were counted on the 3rd,the 7th,the 10th,the 16th and the 19th day; meanwhile,the pupae amount was recorded,and the pupae weight was measured at the 24th h after pupation. [Result] The survival curves,pupation rates and pupae weights of S. exigua feeding on different tissues of transgenic cotton were not significantly different from those of S. exigua feeding on the corresponding tissues of conventional cotton; pupation rate of S. exigua feeding on different leaves of the same cotton variety were not significantly different from each other,but all higher than that of S. exigua feeding on the flowers of that cotton; and there were no differences among pupation weights of S. exigua feeding on different leaves or flowers of the same cotton variety. [Conclusion] Transgenic cotton showed weak resistance to S. exigua. Hence,in the transgenic cotton fields,more attention should be paid to occurrence trend of S. exigua and its control.

草地贪夜蛾(Spodoptera frugiperda)与东方粘虫(Mythimna separata)种间竞争的室内模拟研究

研究草地贪夜蛾(Spodoptera frugiperda)和东方粘虫(Mythimna separata)在室内以不同的初始种群密度(50头草地贪夜蛾初孵幼虫+50头东方粘虫初孵幼虫;25头草地贪夜蛾初孵幼虫+50头东方粘虫初孵幼虫;10头草地贪夜蛾初孵幼虫+50头东方粘虫初孵幼虫)取食相同寄主时二者的种群竞争行为并分析原因。结果表明,在以小麦苗为寄主的条件下,当初始种群为50头草地贪夜蛾+50头东方粘虫时,混合后13 d,东方粘虫存活率为0,而草地贪夜蛾的存活率为51.0%;随着初始混合种群中草地贪夜蛾比例的下降,混合后13 d,各处理中东方粘虫的存活率逐渐增加,2种昆虫种群达到共存。在以玉米苗为寄主的条件下,当初始种群为50头草地贪夜蛾+50头东方粘虫时,混合后10 d,东方粘虫存活率即为0,而草地贪夜蛾的存活率为81.0%;随着初始混合种群中草地贪夜蛾比例的下降,混合后13 d,各处理中东方粘虫均不能完成幼虫历期,2种昆虫种群不能达共存。草地贪夜蛾和东方粘虫在相同生态位的种群竞争中,草地贪夜蛾具有明显的优势;无论寄主为小麦还是玉米,东方粘虫在与草地贪夜蛾的混合种群中每日存活率通常低于草地贪夜蛾及单独饲养的东方粘虫种群,甚至不能完成幼虫发育,造成东方粘虫种群可能被草地贪夜蛾取代。

高效简便合成斜纹夜蛾Spodoptera litura F.性信息素成分(Z,E)-9,11-十四碳二烯-1-醇乙酸酯

高效简便合成高纯度斜纹叶蛾性信息素,为该虫生物防治提供技术支持。以(E)-2-戊烯-4-炔-1-醇为出发原料,制成(Z,E)构型的烯基碲试剂,然后与有机铜试剂偶联得到构型保持的(Z,E)共轭二烯,成功合成斜纹夜蛾性信息素成分(Z,E)-9,11-十四碳二烯-1-醇乙酸酯(5),纯度(对映体过量值e. e.)达到99. 5%。

Photoactivated Activities on Spodoptera litura Cell, Singlet Oxygen and Photostability of Photosensitizers

[Objective ]The aim of this study was to improve the photostability of pho-tosensitizers. [Method] 2,5-Diphenylthiophene and 2,5-dithienylethynylthiophene were synthesized by replacing thiophene rings of α-terthienyl （α-T） with benzene rings. Photoactivated activities on Spodoptera litura （SL） cells, singlet oxygen with UV and photostability of photosensitizers were investigated. [Result] The cytotoxicity of pho-tosensitizer 2,5-diphenylthiophene on SL cells was 0.22 and 0.16 μg/ml after treat-ment for 24 and 48 h, respectively, while that of 2,5-dithienylethynylthiophene on SL cells was 0.06 and 0.04 μg/ml. Singlet oxygen of 2,5-diphenylthiophene and 2,5-dithienylethynylthiophene was 1.047 5, 1.529 4 μg/mmol under UV, respectively. Degradation dynamic equations of 2,5-diphenylthiophene and 2,5-dithienylethynylthio-phene in methanol were Ct= 5.227 1e-0.006 1t, Ct= 5.084 2e-0.097 3t and half life was 111.79, 7.12 h. [Conclusion] Photosensitizer 2,5-diphenylthiophene has high singlet oxygen production ability, and high photoactivated cytotoxicity on SL cells under UV. Moreover, 2,5-diphenylthiophene has overcome the deficiency of photoactivated in-secticides, which is not applied directly in field because it degrades quickly in the environment.

Field Trials of 20% Tebufenozide SC against Spodoptera exigua Hbner

[Objective] The study was aimed to determine and evaluate control effect and security of 20% tebufenozide SC against Spodoptera exigua HObner, which would provide technical support for its promotion and utilization. [ Method] By using foliar spray method, control effects of different concentration of 20% tebufenozide SC and 25 g/L deltamethrin EC against S. exigua were determined. [ Result] 20% tebufenozide SC had better control effects on S. exigua. After spraying for 3 and 7 d, control effects of 20% tebufenozide SC in each treatment could reach 81% and 84%, which was higher than 25 g/L deltamethdn EC treatment. [ Conclusion] 20% tebufenozide SC for controlling S. exigua had good effect, which had permanent effectiveness for over 7 d. It also caused less environmental pollution, and was safe to cabbage, being the ideal pesticide for controlling S. exigua in vegetables.

Application of Spodoptera litura Nucleopolyhedrovirus for Crop Pest Control

The laboratory bioassay and field control efficacy of Spodoptera litura nucleopolyhedrovirus（Spli NPV） Chenzhou strain were preliminarily examined. The efficient artificial propagation method was to feed the host larvae with virus suspension,and the average mortality of the insects was 65.0%. The death peak of the pests appeared 4-8 d after virus infection. The high temperature, high humidity and poor light could help the virus infection and propagation. Filed control efficacy of Chenzhou strain was 86.6% in laboratory, which was better than of another commercial strain. The corrected control efficacy of this strain was 88.4% the field, which was higher than that of avermectin pesticide significantly. It was detected that the occlusion body（OB） concentration of the initial virus＇ s stock solution was 1.03×1011OBs/ml,and it was a strong SpliNPV strain, as it showed an excellent efficacy to control the pest Spodoptera litura, and thus there will be a good prospect of application and development of this SpliNPV strain.

抗Spodoptera f.病毒单克隆抗体的初步研制

本文介绍了 Spodoptera frugiperda 病毒多角体及病毒粒子的提纯方法。粗提材料先通过40%蔗糖,在10000r/min 下离心15分钟,随后悬浮于0.01M Tris 缓冲液,25～65%蔗糖的连续梯度中,于40000 r/min 下离心30分钟。取出多角体的条带,洗除游离残存的蔗糖,透析过夜。将多角体在4℃,0.01MNa_2CO_3,0.01MEDTA,0.17M NaCl,pH=1下,作用1小时,随后调节 pH 到8.5～8.9,2000g,离心10分钟。该制剂在4℃下,25～60%蔗糖梯度中,24000r/min,离心2小时。随后取出病毒粒子,重新悬浮于蒸馏水中,于—70℃下贮藏备用。每个 BALB/C 小白鼠免疫4～5次,最后一次注射是在融合前4～7天。将2×10~8脾细胞与2×10~7P_3×63或 SP-2骨髓瘤细胞混合,并用50%PEG(Sigma)融合,用间接酶联免疫法进行筛选阳性杂交瘤细胞,强阳性者进行克隆化。以多角体及病毒粒子为抗原者,均建立了10株能产生特异性单克隆抗体的杂交瘤细胞株,该抗体的效价较高,并进行了血清学的分类。

Control of Tobacco Cutworm Moth Spodoptera litura Fabricius (Lepidoptera,Noctuidae) by Sex Pheromone Trapping Technology

[Objective] The paper was to promote using synthetic sex pheromone lures to control tobacco cutworm moth（Spodoptera litura Fabricius） .[Method] Three layers of pheromone traps for S.litura were set in the field at the density of 26 m×26 m（one trap/676 m2） to carry out field control test.[Result] The amount of egg massed reduced by 62.16% after trapping by sex pheromone under the density,and the larvae population was equivalent to those in the conventional control field with pesticides,the control effect was continuous,stable and significant.The larger the control area was,the better the effect was.[Conclusion] Using sex pheromone could effectively control S.litura and reduce pesticide usage for over 80% with economic,safe and efficient features,which should be incorporated into the technical control system of S.litura.

交配和温度对甜菜夜蛾(Spodoptera exigua)雌蛾性信息素产生的影响

研究表明 ,交配对甜菜夜蛾雌蛾性信息素各组分的滴度、比例及其在个体间的变异均无显著的影响 ,因此交配不影响雌蛾在下一暗期的再次求偶和交配 .环境温度对甜菜夜蛾性信息素的产生则有显著的影响 .15～ 2 5℃最有利于甜菜夜蛾性信息素的产生 ,而 10℃低温和 35℃高温则使性信息素产生受到明显影响 ,其中以 10℃低温的影响更甚 .10℃低温处理不仅使各组分的滴度产生显著改变 ,而且使二元性信息素组分的比例受到显著影响 ,并使二元组分通讯信道的个体间变异明显增大 (CV >10 % ) .这些改变必将扰乱甜菜夜蛾雌雄间的正常交配 .