Combining WV-2 images and tree physiological factors to detect damage stages of Populus gansuensis by Asian longhorned beetle (Anoplophora glabripennis) at the tree level

Background:Anoplophora glabripennis(Motschulsky),commonly known as Asian longhorned beetle(ALB),is a wood-boring insect that can cause lethal infestation to multiple borer leaf trees.In Gansu Province,northwest China,ALB has caused a large number of deaths of a local tree species Populus gansuensis.The damaged area belongs to Gobi desert where every single tree is artificially planted and is extremely difficult to cultivate.Therefore,the monitoring of the ALB infestation at the individual tree level in the landscape is necessary.Moreover,the determination of an abnormal phenotype that can be obtained directly from remote-sensing images to predict the damage degree can greatly reduce the cost of field investigation and management.Methods:Multispectral WorldView-2(WV-2)images and 5 tree physiological factors were collected as experimental materials.One-way ANOVA of the tree’s physiological factors helped in determining the phenotype to predict damage degrees.The original bands of WV-2 and derived vegetation indices were used as reference data to construct the dataset of a prediction model.Variance inflation factor and stepwise regression analyses were used to eliminate collinearity and redundancy.Finally,three machine learning algorithms,i.e.,Random Forest(RF),Support Vector Machine(SVM),Classification And Regression Tree(CART),were applied and compared to find the best classifier for predicting the damage stage of individual P.gansuensis.Results:The confusion matrix of RF achieved the highest overall classification accuracy(86.2%)and the highest Kappa index value(0.804),indicating the potential of using WV-2 imaging to accurately detect damage stages of individual trees.In addition,the canopy color was found to be positively correlated with P.gansuensis’damage stages.Conclusions:A novel method was developed by combining WV-2 and tree physiological index for semi-automatic classification of three damage stages of P.gansuensis infested with ALB.The canopy color was determined as an abnormal phenotype that could be directly assessed using remote-sensing images at the tree level to predict the damage degree.These tools are highly applicable for driving quick and effective measures to reduce damage to pure poplar forests in Gansu Province,China.

Characteristics of Cellulases from Anoplophora glabripennis Motsch (Coleoptera: Cerambycidae)

The property of major cellulases from the guts of Anoplophora glabripennis larvae have been characterized. The optimal temperatures of both β 1,4 glucosidase (β glucosidase) and endo β 1,4 endoglucanase (endoglucanase, Cx) are 40℃. The β glucosidase was optimally active at pH 4\^8, while the optimal activity of the endoglucanase occurred at pH 4 4 5 6 The endoglucanase was active with a wide range of pH and temperature, the levels of activity from 25℃ to 50℃ were more than 80%, and the activity remained 60% between pH 3 2 and pH 7 2. The endoglucanase exhibited higher thermal stability than β glucosidase. Both enzymes lose their activities by heat treatment at 60℃. Two isozymes of endoglucanase were detected in sodium carboxymethylcellulose polyacrymide gels (CMC gel) by chemical colorization, and purified by elution from the gel slices. The molecular weights of the two isozymes were estimated as 26kD and 39kD respectively. Moreover molecular characteristics of the two isozymes are currently underway.

Phylogenetic Analysis of the 16S rDNA of a Strain Isolated from Diseased Larva of Anoplophora glabripennis (Motsch.)

[ Objective] Study on the phylogenetic analysis of the 16S rDNA and insecticidal characteristics of strain BH-1 isolated from diseased larva of Anoplophora glabripennis （Motseh.） [ Method ] The strain was identified by routine method and inoculated onto healthy Anoplophora glabripennis （Motseh.） for observing insecticidal effect, further 16S DNA was amplified by the specific primers for sequencing and homology analysis. [ Result] The mortality of second instar ofAnoplophora glabripennis（ Motseh. ） reached 72.7% 8 d after 10^10cfu/ml BH-1 was inoculated. The homology of 16S DNA sequences between BH-1 and Serratia marcescens accessed in GenBank reached 99.5%. Combined with the results of routine identification, BH-1 was identified as S. marcescens. [Conclusion] BH-1 could be used for biological control ofAnoplophora glabripennis （Motsch.）.

茉莉酸甲酯喷施和光肩星天牛(Anoplophora glabripennis(Motschulsky)咬食后五角枫释放的挥发物

茉莉酸甲酯喷施和光肩星天牛(Anoplophora glabripennis(Motschulsky)咬食后五角枫(Acer mono Maxim.)植株均诱导产生了乙酸丁酯、2-壬醇、乙酸己酯、3-甲基-2-丁醇、1-辛烯、里那醇、3-蒈烯、1-丁醇、(Z)-2-己烯醛9种正常植株中没有检测到的挥发物。两种处理均诱导或促进了萜烯类、醇类和醛类挥发物的大量释放,且乙酸-3-己烯酯、乙酸乙酯、己醇、反-2-己烯醇、乙基己醇、1-辛烯、石竹烯、法尼烯等挥发物的时序变化趋势也非常相似。因而推测光肩星天牛咬食五角枫后在植物体内诱导产生了茉莉酸信号传导途径。

Electrophysiological and Behavioral Responses of Adult Anoplophom glabripennis (Motschulsky) to Volatile Components of Host-Plant

Electrophysiological and behavioral responses of adult A. glabripennis (Motsch.) to volatiles from ashleaf maple (Acer negundo L.) were investigated to identify semiochemicals involved in host location. Measurable electroantennogram (BAG) responses were elicited to all compounds tested, the most effective antennal stimulants were trans-2-hexen-1-al,decyl aldehyde and trans-2-hexenl-ol.These profiles were similar between males and females. In Y-tube olfactometer bioassays, above three compounds with certain concentration, trans-2-hexen-l-al (1%), trans-2-hexen-l-ol (1%) and decyl aldehyde (10%), were significantly attractive to the adults in laboratory. The results show that either BAG or olfactory responding to a particular volatile compound are markedly influenced by the concentration.

Cellulase in Anoplophora glabripennis adults emerging from different host tree species

In order to investigate different kinds of cellulase in insect pests, we selected male and female adults of Anoplophora glabripennis （Motschulsky） emerging from four different host species （Populus alba var. pyramidalis, P. nigra var. thevestina （Dode） Bean., P. simonii × P. pyramidliscr cv. Opera 8277 Hsu. and Salix matsudana f. lobato-glandulosa） as our research material. The enzyme activitives of three kinds of cellulase in the intestines of the adult insects were measured. The Cx-cellulase isozymes were detected with a CMC-incorporated polyacrylamide gel. The results show that： there are no statistically significant differences between the enzyme activities of males and females emerging from the different host species. The order of magnitude in activity is： Cx-cellulase 〉 β-glycosidase 〉 C1-cellulase. When the adults emerge from the same host species, there are no statistically significant differences between male and female enzyme activities of β-glycosidase and C1-cellulase, but the enzyme activity of Cx-cellulase of males is clearly higher than that of females. The patterns and migration of Cx-cellulase isozymes of males and females emerging from differ-ent hosts trees are clearly not different, and neither are they different when emerging from the same hosts.

Cellulase in Anoplophora glabripennis adults fed on original host tree species and non-original host trees

Cellulase activities of Anoplophora glabripennis （Motsch.） adults from two host plants （Populus simonii x p pyramidliscr cv. Opera Hsu. and Salix matsudana Koidz） fed on three different host tree species （Acer negundo Linn., S. matsudana Koidz and P simonii x P pyramidliscr cv. Opera Hsu.） were investigated. Enzyme activities of endoglucanase and β-glucosidase in the intestines of the insects were measured. The results show that there are no statistically significant differences in the enzyme activities of endoglucanase between male and female insects from the two host plants fed on three host trees, neither inβ-glucosidase. No statistically significant differences in the enzyme activities of endoglucanase and β-glucosidase were found between males and females from the two plants fed on three host tree species, except that the endoglucanase activity in males from the opera poplar fed on Hankow willow is lower than that fed on ash-leaf maple and opera poplar.

Oviposition Site Selection of Anoplophora glabripennis in Sugar Maple (Acer saccharum) and Its Gnawing Nidus Oviposition Habits

[Objective] The paper was to explore the oviposition site selection of Anoplophora glabripennis in sugar maple and its gnawing nidus oviposition habits. [Method] Through field and indoor rearing observation, the oviposition site selection of A. glabripennis in sugar maple was studied, and the gnawing nidus oviposition habits were analyzed. [Result] The height of oviposition site of A. glabripennis in sugar maple, the number observation holes （gnawing nidus oviposition points） and bark thickness in oviposition site showed linear correlation with diameter of branch at breast height. The gnawing nidus oviposition habit of A. glabripennis in sugar maple was mainly divided into 4 stages： gnawing nidus site selection, gnawing nidus, oviposition and nidus sealing, the duration from gnawing nidus to nidus sealing was（38.29±16.47）min. [Conclusion] The study provided reference for comprehensive prevention of A. glabripennis in greening tree species sugar maple, as well as further study on reproductive behavior and regulation mechanism of A. glabripennis.

光肩星天牛成虫光行为反应

对光肩星天牛(Anoplophora glabripennis)成虫光行为进行研究,探讨利用灯光诱捕监控其种群的可能性。在室内暗光周期下,以高压氙灯和不同光波的发光二极管(LED)红光灯为光源,配合滤光片和中性衰减片,测试光肩星雌雄两性对不同光强度、不同波长光源的行为反应。结果表明:当相对光强度为100%时,可以引起距离光源2.0 m雌雄两性的飞行趋光行为,其中雄性的起飞率高于雌性;随着光强度的降低,雌雄两性的趋光活性随之减弱;相对光强度为100%和50%时,雌雄两性的都表现出明显的避光行为,雄性的避光距离大于雌性;随着光强度的降低,雌雄两性的避光活性随之减弱,当相对光强度降为25%时,雌雄两性均无避光反应。雌雄两性对370 nm的紫外光和600~700 nm的红光趋向性最强,其次是400~500 nm蓝紫光,对500~600 nm黄绿光趋向性最弱;对620~630、640~650及655~665 nm波段的LED红光行为反应没有差别。高强度的光源能引起光肩星天牛远距离趋光行为,但也会引起明显的避光反应,这个行为特性表明灯光诱捕不适合用于监控该天牛种群。

光肩星天牛胁迫声及种内空间运动行为

为了利用行为调制手段防治害虫,以光肩星天牛(Anoplophora glabripennis)为研究对象,在实验室内对光肩星天牛雌雄两性胁迫声进行录制和分析,分别在光周期和暗周期对光肩星天牛进行行为生测,分析胁迫声对光肩星天牛空间运动行为的影响。结果表明:光肩星天牛雄性胁迫声音组持续时间短于雌性、频率明显高于雌性,但雌雄胁迫声对空间运动行为的影响没有差异。在光周期,胁迫声对天牛向上爬行及水平运动均没有影响;对雄性起飞行为有抑制作用,但对雌性起飞行为没有影响。在暗周期,胁迫声对雌雄两性水平爬行有驱离作用,降低了天牛趋光爬行的活性;对雄性起飞行为没有影响,但对雌性起飞行为有促进作用。光肩星天牛胁迫声对种内个体具有警戒信号作用,这种作用与光周期相关并对雌雄两性的行为影响有所不同。

空间体积及光照对光肩星天牛4种行为活动的影响

为明确空间体积对光肩星天牛成虫交配、取食、移动和静息行为的影响,室内利用5种体积规格不同的容器(1000、4000、8000、16000、32000 cm^(3))进行连续5 d的试验观察。研究结果显示:(1)光肩星天牛雌、雄虫交尾行为、取食行为、移动行为发生的频次均随着体积的增大而减小;在不同空间体积中除雌、雄成虫静息活动不存在差异外,交配、取食和移动活动雌、雄成虫均存在差异;(2)1000 cm^(3)空间下取食活动、4000 cm^(3)移动活动、16000 cm^(3)取食活动的雌、雄成虫之间存在显著差异;(3)在有光照时,1000 cm^(3)空间下的取食活动、静息活动和32000 cm^(3)的静息活动以及无光照时,4000 cm^(3)的移动、静息活动、8000 cm^(3)的移动活动和32000 cm^(3)静息活动的雌、雄成虫之间存在显著差异;(4)空间体积对光肩星天牛不同行为活动的日节律存在影响。综上所述,光肩星天牛的行为活动会受到空间体积大小及光照的影响。

Is there hybridization between 2 species of the same genus in sympatry?——The genetic relationships between Anoplophora glabripennis,Anoplophora chinensis,and putative hybrids

Anoplophora glabripennis(Asian longhorn beetle,ALB)and Anoplophora chinensis(Citrus longhorn beetle,CLB)are native forest pests in China;they have become important international quarantine pests.They are found using the same Salix aureopendula host tree of Cixi,Zhejiang province,China.On this host tree,we collected additional beetles that appeared to be morphologically intermediate between ALB and CLB.By using a stereoscope,we observed that there were several bumps on the base of the elytra,which was inconsistent with ALB,which typically has a smooth elytral base,but was more like CLB,which has numerous short tubercles on the elytral base.Given their sympatry and intermediate morphology,we hypothesized that these may represent ALB×CLB hybrids.We studied the genomic profiles for 46 samples(ALB,CLB,and putative hybrids)using genotyping-by-sequencing(GBS)providing a reduced representation of the entire genome.Employing principal component analyses on the 163 GBS-derived single nucleotide polymorphism data,we found putative hybrids tightly clustered with ALB,but genetically distinct from the CLB individuals.Therefore,our initial hybrid hypothesis was not supported by genomic data.Further,while mating experiments between adult ALB and CLB were successful in 4 separate years(2017,2018,2020,and 2021),and oviposition behavior was observed,no progeny was produced.Having employed population genomic analysis and biological hybridization experiments,we conclude that the putative hybrids represent newly discovered morphological variants within ALB.Our approach further confirmed the advantage of genome-wide information for Anoplophora species assignment in certain ambiguous classification cases.

取食洋白蜡和旱柳光肩星天牛幼虫肠道中的细菌多样性差异及关键纤维素降解细菌筛选

【目的】从肠道细菌多样性角度探究光肩星天牛幼虫对传统抗性树种洋白蜡的适应性原因。【方法】基于16S rDNA高通量测序技术,分别对用洋白蜡、旱柳饲喂的光肩星天牛幼虫肠道细菌进行了分子鉴定及多样性分析;然后通过富集培养,从未经饲喂的幼虫中筛选出了31株纤维素降解细菌,以透明水解圈直径(D)/菌落直径(d)为标准初步测定了各菌株纤维素降解能力;对降解能力最强的4个菌株进行了滤纸复筛试验。【结果】使用洋白蜡饲喂后,厚壁菌门、芽孢杆菌纲、乳杆菌目、链球菌科、乳球菌属为优势类群;使用旱柳饲喂后,厚壁菌门、芽孢杆菌纲、乳杆菌目、肠球菌科、肠球菌属为优势类群;变形菌门、γ-变形菌纲、肠杆菌目、肠杆菌科、拉乌尔菌属在两者中都为优势类群。两者肠道细菌群落最显著的差异在于,取食洋白蜡幼虫链球菌科、乳球菌属相对丰度显著高于取食旱柳的幼虫,而肠球菌科、肠球菌属相对丰度显著低于取食旱柳的幼虫。直接取食洋白蜡枝干的幼虫肠道纤维素降解细菌种类丰富,隶属于4门、5纲、5目、7科、7属,15种;优势属包括微杆菌属、纤维单胞菌属、假单胞菌属;其中纤维素降解能力最强的4个菌株分别为2株假单胞菌和2株产黄纤维单胞菌;二者在滤纸复筛试验中显著地分解了滤纸,进一步验证了其良好的纤维素降解能力。【结论】在取食洋白蜡光肩星天牛幼虫肠道中,链球菌科、乳球菌属为优势类群,可能发挥重要功能但不直接降解纤维素;放线菌门下的微杆菌属、纤维单胞菌属和变形菌门下的假单胞菌属非优势类群但纤维素降解能力强,可能发挥降解纤维素的功能;上述菌群共存于光肩星天牛肠道,参与其适应洋白蜡的过程。

不同树种树皮物理特征与光肩星天牛危害的关系

为了明确不同树种树皮物理特性对光肩星天牛Anoplohora glabripennis刻槽产卵的影响。在调查光肩星天牛对甘肃省河西地区不同树种危害情况的基础上,对其4种常见寄主(新疆杨Populus alba var.pyramidalis、二白杨Populus gansuensis、柳树Salix babylonica、沙枣Elaeagnus moorceroftii)的树皮粗糙度、厚度、硬度及木质部厚度等物理特征进行测量,并对寄主物理特征与危害程度进行相关性分析。结果表明:光肩星天牛在不同寄主上的刻槽数量为二白杨>柳树>沙枣>新疆杨,羽化孔数量为:二白杨>柳树>新疆杨>沙枣,其中沙枣虽有较多刻槽但未发现天牛羽化孔。柳树与二白杨的树皮粗糙度和树皮厚度显著大于新疆杨。沙枣木质部厚度最大,二白杨的木质部厚度最小,2种杨树的树皮硬度均较低。相关性分析显示光肩星天牛的寄主选择与寄主树皮粗糙度和树皮厚度呈正比;与木皮比值呈负相关。树皮粗糙度和树皮厚度越大对光肩星天牛危害的抗性越弱,故新疆杨受天牛危害较轻;光肩星天牛虽喜欢危害沙枣树但并不能发育成功,可作为光肩星天牛的诱杀树种。

光肩星天牛对沙枣和新疆杨的偏好性

[目的]新疆杨是目前我国西北地区防护林建设的首选树种,长期单一化的种植模式使其受到了光肩星天牛的较大危害。沙枣对光肩星天牛有一定的诱杀效应,但是否可用于保护新疆杨尚不清楚。[方法]本研究通过测试光肩星天牛成虫对新疆杨和沙枣枝叶气味偏好性和树干产卵试验,以及树木挥发物的触角电位活性测定等,初步评估了沙枣作为保护树种的可行性。[结果]1)当新疆杨vs沙枣枝叶时,雌虫偏好沙枣枝叶气味,占作出选择成虫数的80.65%,雄虫对二者选择无显著差异;2)雌虫触角对新疆杨挥发物中的叶醇和乙酸叶醇酯以及沙枣挥发物中3-蒈烯、乙酸叶醇酯和叶醇表现出电生理活性,新疆杨和沙枣挥发物中叶醇含量之比为2.66:1,乙酸叶醇酯之比为1.19:1,因其含量不同所表现出来的电生理活性刺激强度也不同;3)室内试验新疆杨vs沙枣树干时,雌虫偏好在沙枣上产卵,每个供试树段上的刻槽数达18±1.73个,但单选试验中在新疆杨上的有效产卵率高于沙枣,分别为75.00%和58.33%;4)在林间寄主树干上的套笼试验表明,雌虫在无选择条件下在二者上的刻槽数无显著差异,但幼虫在沙枣上均未成活。[结论]上述结果证实了沙枣对光肩星天牛成虫有一定引诱性,但沙枣在一定区域内是否会有效控制光肩天牛种群的增长,还需进一步的研究。

红花槭标准化栽培管理技术研究

红花槭叶片较大、色泽艳丽,观赏价值突出,近年在国内20余个省区均有引种。为规范红花槭栽培技术,推动产业健康发展,通过细化林地选择、苗木栽植、抚育管理等技术环节,使红花槭栽培过程管理实现可操作化。针对红花槭推广应用限制性因子——蛀干害虫光肩星天牛,该研究从营林措施、物理防治、生物防治、化学防治等方面,综述了光肩星天牛的防治措施,旨在为光肩星天牛的综合防治提供参考。

Current and future control of the wood-boring pest Anoplophora glabripennis

The Asian longhorn beetle (ALB) Anoplophora glabripennis is one of the most successful and most feared invasive insect species worldwide. This review covers recent research concerning the distribution of and damage caused by ALB, as well as major efforts to control and manage ALB in China. The distribution and destruction range of ALB have continued to expand over the past decade worldwide, and the number of interceptions has remained high. Detection and monitoring methods for the early discovery of ALB have diversified, with advances in semiochemical research and using satellite remote sensing in China. Ecological control of ALB in China involves planting mixtures of preferred and resistant tree species, and this practice can prevent outbreaks. In addition, strategies for chemical and biological control of ALB have achieved promising results during the last decade in China, especially the development of insecticides targeting different stages of ALB, and applying Dastarcus helophoroides and Dendrocopos major as biocontrol agents. Finally, we analyze recommendations for ALB prevention and management strategies based on native range and invasive area research. This information will hopefully help some invaded areas where the target is containment of ALB.

糖槭树作为引诱树在园林上防治光肩星天牛的效果分析

以3个受光肩星天牛为害的园林作为试验区,分别记为A、B和C区,其中A区为空白组,不做任何处理;B区为对照组,释放花绒坚甲虫+喷施20%氯虫苯甲酰胺;C区在B区的基础上,移植糖槭树作为引诱树。对3个试验区不同树木梢部枯死数量、光肩星天牛成虫数量和刻槽数量,以及糖槭树上的光肩星天牛成虫数量和刻槽数量进行了分析,评估了糖槭树对光肩星天牛的引诱效果。结果表明,在进行防治后,B、C区的光肩星天牛成虫累计死亡数量显著高于A区;C区原有树木上的光肩星天牛数量、刻槽数量均显著低于B区。综合上述分析可知,释放花绒坚甲虫+喷施20%氯虫苯甲酰胺+移植糖槭树作为引诱树的方法能够有效防治光肩星天牛,起到了保护园林中其他树木的作用。

贵阳市美国红枫光肩星天牛的发生现状及防治措施

2018—2020年,贵阳市共种植美国红枫7000余株,近年来受光肩星天牛危害十分普遍。2021年夏季调查结果显示:贵阳地区美国红枫平均受害的株数占总数的20%左右。光肩星天牛在贵阳地区美国红枫上一年发生一代,以幼虫越冬,3月份越冬幼虫在虫道内开始活动取食,5月开始化蛹,5—8月为成虫期,成虫羽化后,需补充营养。成虫盛期为6月中下旬,7月为产卵盛期。针对该虫的发生危害规律,提出了预防和防治措施,效果较好。

国槐光肩星天牛的防治技术研究

为减轻光肩星天牛对嘉峪关市地区行道树-国槐的损害,以前期受光肩星天牛危害较为严重的国槐树为研究对象,通过观察光肩星天牛的生物学特性,分析总结了当地国槐光肩星天牛的发生规律以及危害性,并分别考察了不同药剂应用树干注药法与树干喷药法对光肩星天牛的防治效果。结果显示:甘肃嘉峪关市地区的光肩星天牛在1年内可发生2次虫害,即3月—5月的越冬幼虫、8月—10月的初生幼虫;40%氧化乐果(10倍液)的虫口减退率与防治效果最好,虫口减退率为94.2%,防治效果为94.8%;3%的噻虫啉微囊悬浮剂(1 000倍液)的虫口减退率与防治效果最好,虫口减退率为84.9%,防治效果为86.6%,将树干注药法与喷药法相结合后可有效提升防治效果,相结合后的虫口减退率为97.7%,防治效果为97.8%。