Abstract The western flower thrips, Frankliniella occidentalis, poses a serious threat to global agriculture because of its feeding damage and virus transmission. Its major aggregation pheromone component neryl (S)-2-methylbutanoate (NMB) is a strong attractant for adult females. However, the molecular mechanisms underlying NMB detection, particularly the role of odorant-binding proteins, remain poorly defined. This study identified and functionally characterized FoccOBP56h as a key mediator of the behavioral response to NMB. qRT-PCR showed that FoccOBP56h is predominantly expressed in the antennae and is significantly upregulated following NMB exposure. Fluorescence binding assays revealed that recombinant FoccOBP56h exhibited high affinity for NMB. Molecular docking and site-directed mutagenesis indicated that Asn90, Met104, and Val105 are important for NMB binding. RNAi-mediated knockdown of FoccOBP56h significantly reduced female attraction to NMB. These findings identify FoccOBP56h as a promising molecular target involved in NMB detection, providing a foundation for developing semiochemical-based strategies for insect behavior manipulation in pest management.

Left-right asymmetries in brain features and behavior have long been considered unique to humans. However, they are now also recognized in vertebrates and invertebrates and exhibit similar structural lateralization across different species. For instance, the olfactory behavior and brain asymmetry of eusocial insects are evident at the population level. Certain solitary insects also exhibit behavioral asymmetry at the population level. This study examined the electroantennogram (EAG) responses, behavioral responses, and gene expression of the right and left antennae in adult diamondback moth (DBM), Plutella xylostella (lepidoptera: plutellidae). The results revealed that among the detected genes (GOBP1, GOBP2, PBP, PBP1, and ORCO), only the GOBP1 gene showed expression variance between the left and right antennae of female DBM. Also, the expressions of GOBP1 and GOBP2 in the antennae of female moths were significantly higher than that in male DBM. For male DBM, EAG responses of the left antenna were higher at differentconcentrations of Z-3-hexenol, Z-3-hexenyl acetate and allyl isothiocyanate compared to the right antenna. Marked differences were found in EAG responses between the left and right antennae of male DBM at 0.15 μg•μL-1 allyl isothiocyanate. For female DBM, EAG responses of the right antenna were higher at differentconcentrations of Z-3-hexenyl acetate and allyl isothiocyanate compared to the left antenna, but there was no statistical difference. In an olfactometer bioassay, the choice rates of male DBMs with intact left antennae were significantly higher than that of the control liquid paraffin at 1.0 μg•μL-1. Also, the choice rates of female DBM with left or right antennae to the three tested plant volatiles at 0.15 and 1.0 μg•μL-1 concentrations were significantly higher than those in liquid paraffin. Moreover, the relative choice rates of the right antennae were slightly higher than those of the left antennae in female DBM, but the results were reversed in male DBM. This study contributes to the understanding of behavioral asymmetry of the left and right antennae of DBM and provides a reference for the lateralization of olfactory behavior in other lepidoptera insects.

Epigenetic modifications are emerging as key regulators of plant stress responses. However, their role in eggplant (Solanum melongena)–western flower thrips (WFTs; Frankliniella occidentalis) interactions remains elusive. WFTs cause substantial economic losses in eggplant cultivation worldwide. Understanding the molecular mechanisms underlying eggplants’ defense is critical for developing resistant varieties. We investigated the function of histone H3 lysine 27 trimethylation (H3K27me3) in modulating the early transcriptional reprogramming of eggplants during WFT infestation. We performed ChIP-seq and RNA-seq on eggplant leaves at an early stage of WFT infestation to elucidate the epigenetic landscape and associated gene expression alterations. ChIP-seq analysis showed that genome-wide enrichment of H3K27me3 was mainly at the transcription start sites, with a notable decrease in WFT-infested plants. Concurrently, RNA-seq analysis identified 2822 genes that were upregulated following WFT infestation. Many of these genes associated with abscisic acid, jasmonic acid, and salicylic acid pathways were upregulated, underscoring their central role in early plant defense. Integrated analysis revealed six genes with decreased H3K27me3 levels and concurrent upregulation, potentially involved in ABA and JA signaling. Thus, removal of the repressive H3K27me3 mark may facilitate the transcriptional activation of early defense genes in eggplants that are crucial in their response to insect herbivory.

The issue that the attraction of leaf odors leading to thrips attacks affecting the yield and quality of Passion fruit (Passiflora edulis)—a high-value tropical crop in southern China has drawn widely attentions. This study aimed to comprehensively investigate the influences of special VOCs in susceptible and resistant passion fruit cultivars on feeding preferences of thrips. To explore the association between VOCs and insect behavior, the aromatic intensity of the selected cultivar leaves was determined. A total of 87 differential volatiles were identified from 423 VOCs using orthogonal partial least squares-discriminant analysis (OPLS-DA, P< 0.05, VIP > 1.0). Metabolic pathway analysis linked the differential volatiles to phenylpropanoid and α-linolenic acid metabolism. The key differential volatiles were fruity odor benzaldehyde and green odor (Z)-3-hexenol, which exhibited the highest rOAVs. Resistant cultivars accumulate high concentrations of benzaldehyde (OAV:191.49), which correlated with thrips attraction; while susceptible cultivars accumulated higher concentration of (Z)-3-Hexenol (OAV: 200.60), associated with repellency. Behavioral assays confirmed thrips preference for benzaldehyde (58% attraction) and aversion to (Z)-3-Hexenol (22% selection). These findings not only could advance our understanding of plant volatile-mediated insect behavior but also enable the development of lures for pest management, while providing a scientific basis for breeding pest-resistant cultivars.

The Hawaiian flower thrips, Thrips hawaiiensis, is a common flower inhabiting pest of various horticultural plant species. It damages flowers and fruits by puncturing. T. hawaiiensis shows a rapidly developed resistance to chemical control. The lack of a high-quality reference genome limits our understanding of the genetics of T. hawaiiensis. Here, we sequenced the genome of T. hawaiiensis using Oxford Nanopore sequencing technology, Illumina, and Hi-C technology, yielding a genome assembly of 287.59 Mb with scaffold N50 of 13.84 Mb. BUSCO analysis demonstrated the T. hawaiiensis genome assembly has a high-level completeness of 98.7%. In total, 18,289 protein-coding genes were annotated and 26.69% of the genome were annotated as repeats. Our study presents the first high-quality genome assembly of T. hawaiiensis and lays the foundation for further studies on thrips genetic characteristics and pest management.

Female semiochemicals and allyl isothiocyanate (AITC) attract moths, and the moths use odorant-degrading enzymes (ODEs) to break down the excess odor. By identifying antennae-specific ODEs, researchers have established the molecular foundation for odorant degradation and signal inactivation in insects. This enables further exploration of new pest control methods. Currently, the degradation of female semiochemicals and AITC has received limited attention, inspiring this study to identify target ODEs in diamondback moths through transcriptome analysis. Sequencing of antennae from male adults (MA) exposed to female adults (FA) and AITC yielded a substantial 54.18 Gb of clean data, revealing 2276 differentially expressed genes (DEGs) between the MA and MA-FA treatments, and 629 DEGs between MA and MA-AITC treatments. The analysis of MAs exposed to FAs and AITC identified 29 and 17 ODEs, respectively, mainly involving aldehyde dehydrogenases (ALDHs), alcohol dehydrogenases (ADs), cytochrome P450s (CYPs), and UDP-glucuronosyltransferases (UGTs). Pathway analysis revealed primary enrichment in glycolysis/gluconeogenesis and fatty acid degradation in female adult treatments. In contrast, AITC treatments showed major enrichment in pathways related to pentose and glucuronate interconversions, retinol metabolism, and ascorbate and aldarate metabolism. Additionally, qRT-PCR analysis validated the expression patterns of 10 ODE genes in response to these treatments, with varying results observed among the genes. These findings indicate significant changes in ODE expression levels, providing a molecular foundation for identifying potential targets for behavioral inhibitors.

Plant nutrition is connected to defense against insect herbivores, but the exact mechanism underlying the effect of the nitrogen (N) supply on the anti-herbivore capacity of eggplants (Solanum melongena) has not been studied in detail. Therefore, we examined the impact of low (LN, 0.5 mM) and high (HN, 5 mM) nitrate levels on eggplant resistance against the western flower thrips Frankliniella occidentalis (WFT), a major destructive eggplant pest. Our results showed that LN plants displayed enhanced defense responses to WFT compared to HN plants. This included increased transcript levels of key genes in the jasmonic acid (JA) pathway, the accumulation of JA-amido conjugates (jasmonoyl-isoleucine, jasmonoyl-phenylalanine, and jasmonoyl-valine), JA precursor (12-oxophytodienoic acid), and methyl jasmonate, higher transcript levels of defense marker genes (MPK3, MPK7, and WRKY53), and increased activities of polyphenol oxidase and peroxidase upon a WFT attack. Our findings suggest that N deficiency can prime JA-mediated defense responses in eggplants, resulting in increased anti-herbivore resistance.

Herbivorous insects use plant volatiles to locate hosts, find food, and identify oviposition sites to aid survival and reproduction. Plant volatiles not only regulate the synthesis and release of sex pheromones in insects, but also help them in the search and orientation of sources of sex pheromones. However, after prolonged exposure to plant volatiles, the changes mediating the mating behavior of diamondback moth (DBM) [ Plutella xylostella (L.) (Lepidoptera: Plutellidae)] are unclear. DBMs treated with allyl isothiocyanate, a volatile from cruciferous vegetables, did not show improved rates of mating with a limited effect on mating rhythm. This treatment inhibited mating behaviors in 3-day-old DBMs and decreased mating duration in 5-day-old DBMs. After prolonged exposure to allyl isothiocyanate, the total mating duration of DBM was not significantly different from that after prolonged exposure to n -hexane (control). The longest mating duration after emergence in DBM after prolonged exposure to allyl isothiocyanate was delayed by 1 day compared with exposure to n -hexane. Prolonged exposure to plant volatiles intensified the response behavior of DBM to sex pheromones. However, the amount of Z 11-16: Ald, a major component of the sex pheromone blend exhibited no change in female pheromone glands. Pheromone biosynthesis activating neuropeptide gene ( PBAN ) was down-regulated in DBMs after prolonged exposure to plant volatiles. These findings suggest that prolonged exposure (6 h) to plant-derived volatiles have little effect on the mating behavior of DBM. This study provides practical guidance for applying phytochemicals in pest control by regulating insect behavior.

[目的]研究土荆芥精油对5种杀虫剂毒力的影响,为合理开发利用杂草资源研发环保农药助剂,进而促进害虫持续控制提供依据.[方法]以小菜蛾幼虫为供试昆虫,采用微量点滴法、浸叶法和夹毒法分别测定不同用量土荆芥精油对5种杀虫剂触杀和胃毒作用的影响.[结果]土荆芥精油对敌百虫、氟虫腈和甲氨基阿维菌素苯甲酸盐的触杀毒力表现出较好的增效作用;10 mg/g 土荆芥精油对联苯菊酯增效作用最好,增效比可达9.13,而30 mg/g土荆芥精油对联苯菊酯则表现为拮抗作用;土荆芥精油对灭多威均表现为拮抗作用.夹毒法毒力测定结果表明,土荆芥精油对灭多威、氟虫腈、联苯菊酯的胃毒毒力均表现出较好的增效作用;对甲氨基阿维菌素苯甲酸盐和敌百虫均表现为拮抗作用.浸叶法毒力测定结果表明,土荆芥精油对氟虫腈、联苯菊酯、甲氨基阿维菌素苯甲酸盐和敌百虫胃毒毒力均表现出很好的增效作用,对灭多威表现出拮抗作用.[结论]土荆芥精油对氟虫腈和联苯菊酯(10 mg/g 土荆芥精油)均有良好的增效作用,可显著增加其杀虫毒力,是提高杀虫剂药效的优选助剂.

In order to evaluate the toxic effects and risks of herbicides on Coccinella septempunctata, the acute contact toxicity tests of 10% metamifop emulsifiable concentrate（EC）, 10% oxaziclomefone suspension concentrate（SC） and 20% isoxaflutole suspension concentrate（SC） to C.septempunctata were conducted by tube method. The results showed that toxicity LR 50 of 10% metamifop emulsifiable concentrate（EC）, 10% oxaziclomefone suspension concentrate（SC） and 20% isoxaflutole suspension concentrate（SC） to the C.septempunctatas were＞3.61×10 2 g a.i./ha, ＞1.485×10~2 g a.i./ha, ＞3.60×10~2 g a.i./ha. The relative safety factors of 10% metamifop emulsifiable concentrate（EC）, 10% oxaziclomefone suspension concentrate（SC） and 20% isoxaflutole suspension concentrate（SC） were less than or equal to 5, which belonged to medium and below-risk pesticides. The risk of 10% metamifop emulsifiable concentrate（EC）, 10% oxaziclomefone suspension concentrate（SC） and 20% isoxaflutole suspension concentrate（SC） to C.septempunctata were acceptable for in-field and off-field exposure scenario(hazard quotients respectively, HQ in ＜0.997,HQ in ＜2.000,HQ in ＜1.000,HQ off ＜0.020,HQ off ＜0.020,HQ off ＜0.020, all HQ in and HQ off ＜5). In conclusion, the above three herbicides were safe for C.septempunctata when applied in the field.

Thrips hawaiiensis (Morgan) (Thysanoptera: Thripidae) is a sap-sucking pest that seriously damages several crops and reduces their economic value. Exposure to low concentrations of insecticides may have a sublethal effect on surviving insects. In order to provide a reference for the rational application of emamectin benzoate, its sublethal effects on the development and reproduction of T. hawaiiensis were evaluated. Pupal development time was significantly shorter in T. hawaiiensis treated with sublethal concentrations of emamectin benzoate (LC10 and LC20) than in control. Female adult longevity and female total longevity were significantly longer following LC20 treatment than in the control and LC10 treatment groups. Nevertheless, male adult longevity and male total longevity were significantly shorter in the LC10 treatment group than in the control and LC20 treatment groups. The sublethal concentration of emamectin benzoate (LC20) significantly shortened the preadult stages and the mean generation. Meanwhile, it significantly increased the finite rate of increase, intrinsic rate of increase, and net reproductive rate. The fecundity was significantly higher after LC20 treatment than after LC10 and control treatments. Compared with the control group, the LC10 and LC20 groups of T. hawaiiensis adults showed a significantly higher expression of the vitellogenin (Vg) and vitellogenin receptor (VgR) genes, which played a key role in increasing their fecundity. These findings suggest that short-term exposure to sublethal concentrations of emamectin benzoate may lead to a resurgence and secondary outbreak of T. hawaiiensis infestation. The results have practical applications for the management of this important and noxious pest.

[目的]黄胸蓟马(Thrips hawaiiensis)是为害枇杷的重要害虫,本研究旨在明确单一色板、色板+单组分信息化合物和色板+双组分信息化合物对黄胸蓟马和有益昆虫的诱集作用,为枇杷园蓟马种群监测与防控及有益昆虫保护提供科学依据.[方法]通过田间试验比较3种颜色粘虫板(黄色、蓝色和白色)和悬挂高度(225 cm、150 cm、75 cm)对黄胸蓟马的诱集效果,在此基础上比较色板+单组分信息化合物(异烟酸甲酯、烟酸甲酯、异烟酸乙酯和烟酸乙酯)和色板+双组分信息化合物(异烟酸甲酯+烟酸乙酯、异烟酸甲酯+异烟酸乙酯、异烟酸甲酯+烟酸甲酯、烟酸甲酯+烟酸乙酯、烟酸甲酯+异烟酸乙酯、烟酸乙酯+异烟酸乙酯)对黄胸蓟马和有益昆虫的诱集效果.[结果]白色粘虫板在悬挂高度 150 cm对黄胸蓟马诱集数量显著高于其他处理组.单组分信息化合物异烟酸甲酯对黄胸蓟马引诱效果最强,诱集雌、雄成虫和黄胸蓟马总成虫数量分别为空白对照组的 4.68倍、8.45倍和 5.56倍;比较 6种双组分信息化合物与对应单组分信息化合物对黄胸蓟马的诱捕效果,发现均对雌成虫呈拮抗作用.10种信息化合物处理组对有益昆虫食蚜蝇、寄生蜂类、草蛉、蜜蜂和胡蜂的诱集数量均较低,食蚜蝇诱集数量最多仅2.73头·板-1·d-1,各处理组益害比值均低于空白对照组,其中异烟酸甲酯处理组最小(1∶285.33).[结论]白色粘虫板与异烟酸甲酯组合对枇杷园花期黄胸蓟马的诱集效果最强,且对有益昆虫影响最小.

Many herbivorous insects rely on plant volatiles to locate their host plants. Vector-borne viral infections induce changes in plant volatiles, which render infected plants more attractive to insect vectors. However, the detailed mechanisms underlying the olfactory responses of insect vectors induced by the volatiles produced by virus-infected plants are poorly understood. Here, we show that volatiles emitted by pepper (Capsicum annuum) plants infected with tomato zonate spot virus (TZSV), particularly the volatile cis-3-hexenal, which is recognized by chemosensory protein 1 of the thrips Frankliniella intonsa (FintCSP1), are more attractive to F. intonsa than the volatiles emitted by non-infected pepper plants. FintCSP1 is highly abundant in the antenna of F. intonsa. Silencing of FintCSP1 significantly decreased electroantennogram responses of F. intonsa antennae to cis-3-hexenal and impaired thrips' responses to TZSV-infected pepper plants and cis-3-hexenal, as assessed using a Y-tube olfactometer. Three-dimensional model predictions indicated that FintCSP1 consists of seven α-helixes and two disulfide bridges. Molecular docking analysis suggested that cis-3-hexenal is positioned deep inside the binding pocket of FintCSP1 and binds to residues of the protein. We combined site-directed mutagenesis and fluorescence binding assays and identified three hydrophilic residues, Lys26, Thr28, and Glu67, of FintCSP1 as being critical for cis-3-hexenal binding. Furthermore, CSP of F. occidentalis (FoccCSP) is also a key olfactory protein involved in modulating the behaviour of F. occidentalis to TZSV-infected pepper. This study revealed the specific binding characteristics of CSPs to cis-3-hexenal and confirmed the general hypothesis that virus infections induce changes in host volatiles, which can be recognized by the olfactory proteins of the insect vector to enhance vector attraction and this may facilitate viral spread and transmission.

ObjectiveThrips hawaiiensis is a significant loquat pest. This study aimed to determine the attractive effects of single-colored sticky traps, colored sticky traps + single semiochemical, and colored sticky traps + two semiochemicals on the capture of T. hawaiiensis and beneficial insects. These findings would provide a scientific basis for the monitoring and control of thrip populations, as well as the conservation of beneficial insects in loquat orchards.MethodA field experiment was conducted to compare the effectiveness of sticky traps of three different colors (yellow, blue, white) hung aboveground at varied heights (225cm, 150cm, 75 cm) in attracting the target insects. Then, at the optimal sticky trap color and hanging height, four groups of traps coated with a single seimchemical (methyl isonicotinate, MI; methyl nicotinate, MN; ethyl isonicotinate, EI; ethyl nicotinate, EN) on each trap, six groups of traps with two seimchemicals (MI+EN, MI+EI, MI+MN, MN+EN, MN+EI, EN+EI) on each trap, and one control group were placed in the orchard to compare the attractant effects of T. hawaiiensis and beneficial insects.ResultWhite sticky traps hung 150cm aboveground attracted the greatest number of thrips. The single methyl isonicotinate semiochemical (MIWT) was most effective in attracting T. hawaiiensis, and the numbers of female, male, and total T. hawaiiensis adult captured were 4.68 times, 8.45 times, and 5.56 times, respectively, that of the control. By comparing the trapping effects of the six two semiochemicals treatments and their corresponding single semiochemical on the capture of T. hawaiiensis adults showed that all of them had antagonistic effects on female adults. However, interestingly and importantly, the captured beneficial insects of the ten semiochemical treatments, such as hoverflies, parasitic wasps, lacewings, bees, and vespids, were all lower than those of the control, and the maximum number of hoverflies captured was only 2.73 thrips per trapper day, and the ratio of trapped beneficial insects : trapped thrips of all the treatments were lower than those of the control, with MIWT treatment showing the least (1:285.33).ConclusionIn the loquat flowering season, the combination of the white sticky trap and methyl isonicotinate had the strongest trapping effect on T. hawaiiensis, with the least effect on beneficial insects.

化学感受蛋白(chemosensory proteins,简称CSPs)除了具有感知化学分子的功能,还与昆虫个体生长与发育、生殖、杀虫剂抗性等密切相关.黄胸蓟马(Thrips hawaiiensis)广泛分布于亚洲热带、亚热带和北美南部,是一种重要的农业和园艺作物害虫.本研究克隆鉴定了黄胸蓟马化学感受蛋白基因ThawCSP1开放阅读框(ORF),然后利用MEGA 7.0软件以邻接法构建ThawCSP1系统发育树,最后利用RT-qPCR、免疫荧光、免疫电镜技术,从mRNA和蛋白水平分析黄胸蓟马ThawCSP1基因的表达情况.结果表明,黄胸蓟马ThawCSP1基因(GenBank登录号:OQ730210)ORF为405 bp,编码134个氨基酸,预测蛋白分子量为15.181 ku.分子进化树显示ThawCSP1与同属缨翅目的西花蓟马、花蓟马和牛角花齿蓟马CSPs序列同源性分别为79.55％、80.30％、76.52％.ThawCSP1基因在黄胸蓟马各个发育阶段均有表达,其中羽化1、5、10d的成虫相对表达量最高,其次是1龄、2龄若虫和羽化15 d的成虫,蛹期的表达量最低;在黄胸蓟马成虫不同组织中,ThawCSP1表达量最高的是触角,其次是足和头部,分别是腹部表达量的222.33、181.60、79.03倍.免疫荧光和免疫电镜观察也表明,ThawCSP1蛋白在黄胸蓟马触角高表达.研究结果将为解析ThawCSP1基因功能提供试验依据,也为基于昆虫CSPs研发高效引诱剂提供了理论依据.

Tomato zonate spot virus (TZSV) is a phytopathogen of the genus Orthotospovirus (Bunyaviridae) that is widespread in many areas of Southwest China. TZSV is mainly transmitted by Frankliniella occidentalis, but its exact infection route remains unclear. To explore this issue, we detected the nucleocapsid protein of TZSV in the digestive systems of first-instar F. occidentalis nymphs fed with TZSV-infected pepper leaves. TZSV infection in the F. occidentalis digestive system begins within 4 h post-first access to diseased plants: The foregut is likely the primary site of infection, and primary salivary glands (PSGs) are the destination. There are three potential routes for TZSV transmission from the alimentary canal to the PSGs: (1) virus dissemination from the midgut to hemocoel followed by movement to the PSGs; (2) accumulation in midgut epithelial cells and arrival at PSGs via tubular salivary glands and efferent ducts; and (3) arrival at epitheliomuscular cells of the forepart of the midgut and movement along the ligament to the PSGs. We tested the transmission efficiency of F. occidentalis in second-instar nymphs and female and male adults. TZSV was transmitted in a persistent-propagative mode by both nymphs and adults, with adults appearing to show slightly higher transmission efficiency than nymphs. We confirmed the presence of all three routes for TZSV transmission in F. occidentalis and determined that like other Orthotospoviruses, TZSV is transmitted in a persistent-propagative manner. These results should facilitate the control of TZSV-related diseases and further our understanding of the transmission biology of Orthotospoviruses in general.

[目的]本研究旨在为阐明小菜蛾Plutella xylostella体温在其防治中的应用价值提供资料.[方法]在不同人工气候箱内温度(环境温度)下,测定小菜蛾2,3和4龄幼虫的体温,建立各龄幼虫体温(y)与环境温度(x)的关系方程;同时测定了不同环境温度下不同浓度阿维菌素、毒死蜱、氟虫腈和高效氯氰菊酯分别处理后小菜蛾3龄幼虫在不同处理时间的体温.[结果]小菜蛾2,3和4龄幼虫体温(y)与环境温度(x)关系方程分别为y=0.95x+1.19(r=0.9463),y=0.95x+1.18(r=0.9988),以及 y=0.93x+1.45(r=0.9989),等温点分别为 22.16℃,21.40℃和 21.41℃.在气候箱温度设定为15℃或40℃时,4种农药都对小菜蛾3龄幼虫体温无影响;而其他温度条件下,农药处理都可能改变小菜蛾3龄幼虫体温.对于阿维菌素,25℃下2,4和8 mg/L处理12h,2和4 mg/L处理24 h,0.5,2,4和8 mg/L处理36 h以及0.5,1,2和8 mg/L处理48 h时3龄幼虫体温均显著高于对照,8 mg/L阿维菌素处理24 h时3龄幼虫体温显著低于对照;30℃下0.5 mg/L处理24 h及1 mg/L处理36 h 3龄幼虫体温显著低于对照,1 mg/L处理48 h和各浓度处理60 h时3龄幼虫体温均显著高于对照;35℃下只有1和8 mg/L处理48 h时3龄幼虫体温显著低于对照.对于毒死蝉,20℃下50,200和800 mg/L处理24 h,100,400和800 mg/L处理36 h时3龄幼虫体温都显著低于对照;25℃下100和200 mg/L处理12 h,800 mg/L处理24 h,100,200和800 mg/L处理60 h时3龄幼虫体温均显著低于对照,而50,100,200和400 mg/L处理24 h,100和200 mg/L处理36 h及100和400 mg/L处理48 h时3龄幼虫体温均显著高于对照;30℃下只有800 mg/L处理24 h时3龄幼虫体温显著低于对照,50,100,200和800 mg/L处理60 h时3龄幼虫体温显著高于对照.对于氟虫腈,20℃下只有0.5 mg/L处理36 h时3龄幼虫体温显著低于对照;25℃下4 mg/L处理12 h和各浓度处理60 h时3龄幼虫体温显著低于对照,0.5 mg/L处理24 h以及0.25,1和2 mg/L处理48 h时3龄幼虫体温均显著高于对照;30℃下0.25和0.5 mg/L处理12 h,0.25和2 mg/L处理24 h,4 mg/L处理48 h以及2 mg/L处理60 h时3龄幼虫体温显著低于对照;35℃下只有0.25和0.5 mg/L处理60 h时3龄幼虫体温显著高于对照.对于高效氯氰菊酯,20℃下2和8 g/L处理36 h,4和8 g/L处理48 h时3龄幼虫体温显著高于对照;25℃下2,4和8 g/L处理12 h时3龄幼虫体温均显著低于对照,0.5,4和8 g/L处理24 h,1,4和8 g/L处理36 h以及1,2和4 g/L处理60 h时3龄幼虫体温均显著高于对照;30℃下0.5和1 g/L浓度处理12 h,0.5,1,4和8 g/L处理24 h以及1,2和8 g/L处理60 h时3龄幼虫体温都显著低于对照.[结论]小菜蛾幼虫自律性体温调节能力低;阿维菌素、毒死蜱、氟虫腈或高效氯氰菊酯处理影响小菜蛾3龄幼虫的体温,影响形式随农药种类和浓度,环境温度及处理时间不同而不同.本研究拓宽了农药毒理学及害虫防治研究内容.

Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is a destructive, invasive pest that has spread rapidly throughout China. Traps for the prevention and control of thrips typically use a single attractant, and few studies have evaluated effective compound combinations. In this study, the attractant effects of ethyl nicotinate and p ‐anisaldehyde on female F. occidentalis were evaluated. Electroantennography recorded the highest depolarization for the mixture of p ‐anisaldehyde and ethyl nicotinate standards at a 1:1 mass ratio, and this depolarization was significantly higher than that of the other compounds investigated. The Y‐tube olfactometer results show that the olfactory responses of female F. occidentalis to ethyl nicotinate, p ‐anisaldehyde, and their mixtures (at a 1:1 mass ratio) at concentrations of 0.05, 0.1, 0.5, and 1 μg μl −1 were significantly higher than those to liquid paraffin. The strongest response was toward 0.05 g l −1 ethyl nicotinate or p ‐anisaldehyde and the 1 g l −1 mixture of p ‐anisaldehyde and ethyl nicotinate standards combined at a 1:1 mass ratio, but high concentration caused a weak reaction. Greenhouse experiments revealed that various concentrations of the attractants were successful in trapping thrips. The attractant mixture at a concentration of 1 g l −1 was the most effective at luring thrips. Compared with traps without any attractants, those with attractants trapped at least double the number of F. occidentalis . Our study is the first to comprehensively evaluate female F. occidentalis responses to p ‐anisaldehyde and ethyl nicotinate using electrophysiological, Y‐tube olfactometer, and greenhouse trapping analyses. The methods used also proved to be valuable for evaluating the potential of attractants to control F. occidentalis .

[目的]本研究旨在明确豆大蓟马Megalurothrips usitatus各个发育阶段消化道形态和超微结构.[方法]运用激光共聚焦显微镜和透射电子显微镜技术观察豆大蓟马若虫、预蛹、蛹和成虫期消化道形态和超微结构.[结果]豆大蓟马消化道由前肠、中肠、后肠及马氏管组成.1龄若虫、2龄若虫、预蛹、蛹、雌成虫和雄成虫的消化道平均长度分别为1 642.65±158.68,2 233.68±133.76,1 264.39±92.43,1 169.81±59.48,2 380.32±196.67和 1 344.31±143.29 μm.前肠分为咽、食道、嗉囊和贲门4个部分,肠壁由外向内分别为肌上皮细胞外层、肌肉层、上皮细胞层和角质层.1和2龄若虫前肠有大量囊泡,角质层不明显.预蛹、蛹和成虫前肠细胞角质层较厚,肌肉也较发达.中肠分为前中肠、中中肠和后中肠3个部分,由外向内分别为肌细胞层和上皮细胞层,靠近肠腔的一侧特化成微绒毛结构.1龄若虫前中肠细胞含有储备物质;2龄若虫前中肠细胞含有髓鞘样结构以及较多的类自噬泡结构;预蛹和蛹中肠细胞含有球晶;成虫前中肠和中中肠细胞含有基底迷路.后肠由回肠和直肠2部分组成,各个发育阶段均具有发达的肌肉层和角质层.马氏管没有肌肉层,上皮细胞包含线粒体、粗面内质网、基底迷路、紧密连接等细胞器或结构.预蛹和蛹的马氏管基部未观察到基底迷路结构,但预蛹马氏管细胞内分布有多泡体.此外,蛹期马氏管细胞质中观察到球晶.[结论]豆大蓟马各个发育阶段的消化道形态结构有明显差异.本研究根据消化道不同部位的形态组成,对其功能进行了推测.研究结果将为进一步解析蓟马类昆虫消化道形态和功能分化提供实验依据.

[目的]本研究旨在探究光周期对小菜蛾Plutella xylostella(Linn.)羽化节律的调控作用,为小菜蛾的季节性种群动态预测提供理论基础.[方法]在自然光周期和逆转光周期条件下,观察小菜蛾每日的羽化情况.[结果]在自然光周期和逆转光周期条件下,小菜蛾蛹在24 h均可以羽化.正常光周期下,羽化行为表现为近似抛物线形昼夜节律,雌成虫通常在黑暗阶段羽化(18:00-6:00),而雄成虫大多在光照阶段羽化(6:00-18:00).在逆转光周期下,小菜蛾蛹的羽化无明显规律.在正常光周期下,雌成虫的羽化频率在光期和暗期没有显著差异,但是,相比于暗期,雄成虫在光期羽化率较高;在逆转光周期后,雌成虫在暗期(6:00-18:00)的羽化数量比光期(18:00-6:00)高,雄成虫暗期的羽化数量比光期低.[结论]光周期逆转后小菜蛾雌成虫和雄成虫的羽化节律明显改变,这将有助于阐明害虫光周期变化与生物钟之间的关系.