褐梗天牛幼虫和成虫空间分布的地统计学研究

褐梗天牛(Arhopalus rusticus Linnaeus)是一种对松、杉、柏等林木危害非常严重的蛀干害虫,主要危害针叶树的衰弱木以及火灾后的枯立木,是继松褐天牛之后携带拟松材线虫能力最强的蛀干害虫。为了更好地控制其危害,深入地研究其种群空间格局,运用地统计学方法分析了3块受害程度不同的油松林内褐梗天牛幼虫和成虫的空间分布特性。结果表明:3种受害程度不同的林分内,褐梗天牛的危害具有显著差异,轻度受害林分内有虫株率为30.8%,中度受害林分内有虫株率为44.3%,而重度受害林分内高达78.3%。根据变异函数曲线图分析得知:轻度受害林、中度受害林和重度受害林内褐梗天牛幼虫种群空间分布最优拟合模型分别为高斯模型、高斯模型和指数模型,成虫的种群空间分布最优拟合模型均为线性模型。在3种林分中褐梗天牛幼虫数量具有明显的空间依赖性,轻度受害林、中度受害林和重度受害林内幼虫数量的空间依赖范围分别是19.10、11.97、61.98m,其空间连续性强度分别是0.646、0.784和0.500;成虫的空间依赖范围分别是43.08、43.23、44.17m,其空间连续性强度分别是0.044、0.021和0.171,但其成虫的数量在空间呈随机分布,没有表现出空间依赖性。根据垂直分布图分析得出:褐梗天牛幼虫和成虫在油松上主要集中聚集在某个高,然后随着高度增加密度降低,随着高度接近地面密度也降低。用Kriging插值法生成的空间分布图显示幼虫在空间分布上具有明显的聚集性,其聚集中心主要集中在林地中心,由林地中心株向整个林地扩散,而成虫则表现为随机分布。     

麦红吸浆虫及其卵寄生蜂混合种群空间格局

运用地统计学方法对不同时期麦红吸浆虫及其卵寄生蜂混合种群(宽腹姬小蜂和尖腹黑蜂)的空间格局进行了分析.结果表明:麦红吸浆虫休眠体的半变异函数的最优模型为球型,成虫的最优模型为球型-指数型,幼虫最优模型为线性有基台型,卵寄生蜂混合种群半变异函数的最优模型为球型-指数型.麦红吸浆虫休眠体、成虫羽化初期、成虫羽化高峰期、幼虫和卵寄生蜂混合种群的空间相关范围分别为53.6、190.6、154.1、4.2和280.3 m,空间变异强度分别为30.5%、95.6%、96.3%、14.9%和95.3%.采用普通克立格插值法模拟的空间分布模拟图可较好地从时间、空间两个角度直观地分析不同时期麦红吸浆虫及其卵寄生蜂混合种群的动态变化.     

云斑白条天牛对核桃、桉树的趋向性和EAG反应

云斑白条天牛Batocera lineaolata严重危害核桃树和桉树,是一种寄主范围较广的蛀干害虫。本研究通过弄清云斑白条天牛对核桃和桉树两种寄主树种挥发物的行为反应差异,为利用信息素监测和防治云斑白条天牛提供理论依据。本研究采用触角电位(EAG)反应和"Y"型嗅觉仪技术测定了云斑白条天牛对寄主核桃和桉树各部位挥发物的趋向性和EAG反应。结果表明:核桃种群的云斑白条天牛成虫对核桃树皮、叶片和嫰枝挥发物的趋向率均高于桉树相应部位挥发物的趋向率。雌性天牛交尾后对核桃树皮的选择性显著高于交尾前对核桃树皮的选择性;相反,雄性天牛交尾后对核桃树皮的选择性显著低于交尾前对核桃树皮的选择性。核桃种群云斑白条天牛成虫对核桃和桉树的树皮、嫰枝和叶片的挥发物均有较强的EAG反应;其中,雌性天牛对核桃树皮挥发物的EAG反应值显著高于雄虫的EAG反应值;未交尾雄虫对桉树嫰枝挥发物的EAG反应值显著高于核桃嫰枝的EAG反应值。可见,来源于核桃种群的云斑白条天牛更趋向于选择核桃,性别和交尾与否对其趋向性和EAG反应也存在一定影响。     

杨树上云斑天牛种群的空间格局及抽样技术

云斑天牛Batocera horsfieldi是我国南方杨树的重要蛀干害虫, 研究云斑天牛种群的空间格局和抽样技术, 可为该虫的危害调查与防治提供理论依据。应用Taylor的幂法则、Iwao m*-m回归分析法及6个聚集指标, 对云斑天牛种群的卵、幼虫、蛹或成虫的空间分布型和抽样技术进行了研究, 并做了影响因素分析。结果表明: 云斑天牛的卵、幼虫、蛹或成虫在杨树上均呈聚集分布, 分布的基本成分是个体群, 其聚集性随密度的增加而增大。运用Iwao m*-m回归中的两个参数α和β值, 计算出了在不同精度下以刻槽、排粪孔和羽化孔为防治指标时的理论抽样数据表及序贯抽样数据表,生产中可查阅使用。     

云斑白条天牛雌雄成虫四个线粒体基因的序列比较

[目的]比较云斑白条天牛Batocera lineolata成虫雌雄个体的4个线粒体基因的序列差异,为研究种群个体分化和系统发育提供借鉴.[方法]以危害杨树云斑白条天牛种群为研究对象,分别提取并扩增云斑白条天牛雌雄成虫的线粒体DNA的COⅠ、COⅡ、Cytb、16S rRNA4个基因.通过序列比对,分析比较4个线粒体基因序列在雌雄成虫个体间的差异.[结果]危害杨树云斑白条天牛雌雄成虫的4个线粒体基因存在差异.在碱基序列相似度方面,COⅡ基因雌雄成虫间差异最大,相似度为98.3％,在比较的650个碱基位点中,2个缺失碱基,8个不一致碱基;其次为COⅠ,相似度为98.6％,比较的714个碱基位点中,5个缺失碱基,2个不一致碱基;再次为Cytb,相似度为98.9％,在比较的472个碱基位点中,4个不一致碱基;差异最小的为16S rRNA,相似度为99.2％,在比较的833个碱基位点中,2个缺失碱基,3个不一致碱基.在碱基含量方面,4个基因雌成虫A+T与C+G含量差值均高于雄成虫,Cyt b基因雌雄成虫A+T高出C+G含量的差值最高分别为40.84％和40.96％,16S rRNA差值其次分别为40.10％和40.70％,COⅡ差值再次分别为38.94％和38.22％,COⅠ差值最小分别为30.52％和30.16％.[结论]危害杨树云斑白条天牛雌雄成虫的mtDNA COⅠ、COⅡ、Cytb、16S rRNA在碱基序列相似度和碱基含量方面均存在差异,在分析种群个体分化和系统发育时,条件允许的情况下可以区分云斑白条天牛雌雄个体.     

荔枝园荔枝蒂蛀虫常规爆发期的种群空间分布格局

荔枝蒂蛀虫Conopomorpha sinensis Bradley是我国最重要的荔枝、龙眼蛀果类害虫之一.为了准确把握荔枝园中荔枝蒂蛀虫的分布规律,以便对该虫的危害盛期进行预测预报和采取防治措施,本文采用生物学统计方法和地理统计学方法对荔枝园中荔枝蒂蛀虫卵、蛹和成虫的空间分布特征进行了研究.结果显示:2019年5月和6月,无挂果荔枝树的有虫株率分别为67.74％和68.57％,而挂果荔枝树的有虫株率达90.91％和91.67％.该时期荔枝园内荔枝蒂蛀虫蛹的半变异函数最佳拟合模型均为球型模型,成虫均为指数模型,而卵在5月和6月的拟合模型分别为球型模型和指数模型.不同时期荔枝蒂蛀虫各虫态的拟合变异函数模型虽存在一定差异,但所指明的空间分布格局均为聚集分布.引起荔枝蒂蛀虫卵和蛹聚集分布主要由生境和自身生物学特性共同所致,但当虫口密度降低时,成虫的聚集分布仅由生境引起.另外,用Kriging插值方法生成的空间分布图显示荔枝蒂蛀虫卵、蛹和成虫均明显趋向于以挂果荔枝树为中心的聚集分布,聚集斑块由聚集中心区域向四周逐渐减小.5月至6月,荔枝蒂蛀虫卵、蛹和成虫在荔枝园内趋向以挂果荔枝树为中心的聚集分布,不同时期荔枝园内荔枝蒂蛀虫的聚集分布成因随种群密度变化有所不同.     

马尾松毛虫空间格局的地学统计学分析

应用地学统计学方法分析了湿地松 马尾松 火炬松林中马尾松毛虫越冬代蛹、第一代卵块和低龄幼虫的空间格局 .结果表明 ,蛹在 0°、45°、90°、1 35°4个方向上的半变异函数曲线为球形 ,在 90°方向上的空间连续性大于其他方向 ;卵块和低龄幼虫的为指数形 ,在各方向上无差异 .蛹、卵块和幼虫在全方向上的半变异函数曲线均为球形 ,呈聚集型的空间格局 ,聚集强度以蛹最高 ,依次是幼虫和卵块 .分别拟合了蛹、卵块和幼虫的半变异函数模型 ,估算了样地各处的密度 ,绘制了密度等值线图     

沙棘木蠹蛾卵和幼虫空间分布的地统计学分析

沙棘木蠹蛾(H olcocerushippophaecolus Hua,Chou ,Fang et Chen)是近几年在内蒙古、辽宁、山西、宁夏和陕西等地大面积爆发的一种钻蛀性害虫,其危害发生在幼虫期,主要危害沙棘(H ippophae rhamnoidea)的根干部。为了有效地控制其危害,深入了解种群的空间结构,利用地统计学方法分析了两种受害程度不同的林分内沙棘木蠹蛾幼虫种群和重度受害林分内卵块的空间分布特性。结果表明:两种受害程度不同的林分内,沙棘木蠹蛾的危害具有显著差异,轻度受害林分内无虫样本所占的比例较大,达70 % ,而重度受害林分内不到2 0 % ;虫口密度在轻度受害林分内超过6头/株的只有6 .9% ,而重度受害林分内高达31.9%。根据全方向的变异函数曲线图分析得知:重度受害林分和轻度受害林分内幼虫种群的空间依赖范围分别为7.3m和87.4 18m,而局部空间连续性强度分别为0 .914和0 .178。重度受害林分内幼虫表现较强的空间聚集性,而轻度受害林分则表现为随机分布。在重度受害林分中,单株沙棘树上沙棘木蠹蛾卵块数量最多的为11个,最少的为1个,有卵株率达72 %。分别采用四种不同的理论模型来拟合卵块的实际变异曲线图,得知其全方向的变异函数曲线为指数型,空间依赖范围大小为3.6 m,局部空间连续性强度为0 .876 ,卵块在重度受害林分中呈现较强     

长鞘卷叶甲种群空间分布格局的生物地理统计学分析

应用生物地理统计学方法分析了长鞘卷叶甲成虫种群的空间分布格局,在3 m×3 m样方下建立东南→西北方向的半方差函数理论模型,并应用克立格插值方法对其种群密度和空间结构进行估计和模拟。结果表明:球状模型对长鞘卷叶甲成虫种群在该方向上的理论半方差函数有较好拟合效果,其空间分布格局为弱聚集型;成虫在山坡竹林与河岸竹林的变程分别为21.2157和38.8266 m,空间聚集分布的连续性强度分别只有0.3633和0.1758,说明种群在研究区内由空间自相关而产生的结构性变异在总变异中所占比例较小,即变异主要由种群结构的随机性成分引起。     

豚草条纹萤叶甲各虫态的空间分布型

豚草条纹萤叶甲Ophraella communa LeSage是恶性入侵豚草(Ambrosia artemisiifolia L.)的天敌,用频次分布拟合和多种聚集指数测度等方法对该叶甲的成虫、幼虫和蛹、卵的空间分布型进行研究。结果表明,豚草条纹萤叶甲卵、幼虫+蛹、成虫的空间分布符合负二项分布,种群个体的空间分布为聚集分布。用几种衡量聚集度的指标,对上述各虫态分布的聚集程度进行测定;然后计算出各虫态田间最适理论抽样数。     

Is host plant choice by a clytrine leaf beetle mediated through interactions with the ant Crematogaster lineolata?

In the grasslands of northeastern Kansas, adult populations of Anomoea flavokansiensis, an oligophagous leaf beetle (subfamily Clytrinae), specialize on Illinois bundleflower (Desmanthus illinoensis) even though other reported host species commonly occur and are simultaneously available. We performed choice feeding tests to examine whether A. flavokansiensis adults have a fixed feeding preference for bundleflower. In choice tests, beetles ate similar amounts of bundleflower and honey locust (Gleditsia triacanthos). In addition, we measured fecundity and longevity of adults in no-choice tests to determine if adults were adapted solely to bundleflower. In no-choice tests, fecundity and longevity were no different for adults feeding on bundleflower and honey locust. We next examined the influence of host plant on the attractiveness of beetle eggs to ants. In northeastern Kansas, Crematogaster lineolata ants are attracted to A. flavokansiensis eggs and carry them into their nests where the larvae hatch and apparently reside as inquilines. C. lineolata exhibited a strong preference for eggs from female A. flavokansiensis that fed exclusively on bundleflower compared to eggs from females that fed exclusively on honey locust. Local populations of A. flavokansiensis in northeastern Kansas may specialize on bundleflower to increase the chances of their eggs being transported by C. lineolata ants into their nests. C. lineolata nests may serve as a predator-free and sheltered environment in which A. flavokansiensis eggs undergo embryogenesis. Received: 1 September 1997 / Accepted: 9 February 1998     

Effects of gamma radiation on different developmental stages of the oriental tobacco budworm,Helicoverpa assulta (Lepidoptera: Noctuidae)

Ionizing radiation is increasingly used as an alternative to post‐harvest crop fumigation by methyl bromide. We studied the effects of gamma irradiation on Helicoverpa assulta (Lepidoptera: Noctuidae) at different stages of development to determine the minimal dose for the prevention of normal emergence of adults. We selected five doses of gamma rays (100, 200, 300, 400 and 500 Gy) based on preliminary experiments and irradiated eggs, larvae, pupae and adults. A dose of 100 Gy to eggs allowed 21.83% of larvae to pupate, but these all died during the pupal stage. A dose of 100 Gy to last‐instar larvae caused larval or pupal death, or the emergence of abnormal adults; no normal adults developed. Irradiation of pupae with doses of 300 Gy and above resulted either in their death or emergence of abnormal adults; however, after 100 or 200 Gy, normal adults emerged and F₁ eggs were produced, but no eggs hatched. Following irradiation of adults, eggs were produced at all doses, although the numbers were significantly decreased compared to untreated controls (P < 0.05; 69.45–125.50 vs. 475.05 eggs per female); however, none of the eggs hatched. As prevention of normal emergence is a key outcome for measuring the effectiveness of radiation, then the 100 Gy dose was effective for irradiation of eggs and larvae, and 300 Gy for pupae.     

Why do Luehdorfia butterflies lay eggs in clusters?

Luehdorfia butterflies lay eggs in clusters. Clones of their host plants (Asiasarum and Heterotropa) are distributed pacthily among the understory of deciduous forests. Groups of Luehdorfia larvae often exhaust the clones and may wander over the forest floor seeking new clones. The highest mortality observed is during this wandering period. To elucidate why Luehdorfia butterflies lay eggs in clusters, a simulation experiment was made for hypothetical populations which lay eggs in clusters or singly. Field data on larval mortality, consumption, density of host clones and leaf weight for Luehdorfia japonica were incorporated into the model. The predictions of the simulation were: (1) When the egg density is low, the single egg type could leave many more pupae than the egg clustering type, but when the egg density is high, the former might leave smaller number of pupae than the latter; and (2) There are optimal sizes of egg clusters for different egg densities and the optimal size becomes larger as the egg density increased.     

Effects of fragmentation of secondary broadleaf deciduous forests on populations of the near-threatened butterfly, Sasakia charonda (Lepidoptera, Nymphalidae), in central Japan

We examined the effects of fragmentation of secondary broadleaf deciduous forests (secondary forests) on populations of the near-threatened butterfly, Sasakia charonda, in central Japan. Regression analyses revealed that the number of overwintering larvae per host tree significantly increased when the area of secondary forest patches and the Isolation Index of the forest patch increased and the distance from secondary forest patches containing the focal host trees to the nearest secondary forest patch decreased. There was a significantly positive correlation between the number of overwintering larvae and the number of host trees in the neighborhood. The host trees were primarily distributed at the edges of secondary forests. From the results of the backward elimination method of multiple linear regression analysis, independent variables other than patch area were eliminated, and the standardized partial regression coefficient of the patch area was significant. This result suggested that a contiguous distribution of large secondary forest patches with many host trees is very important to conserving this butterfly species.     

栎黄枯叶蛾低龄幼虫空间分布的地统计学分析

栎黄枯叶蛾(Trabala vishnou gigantina Yang)是近年在陕西吴起发现的严重危害沙棘的一种食叶害虫。为了准确把握栎黄枯叶蛾幼虫的分布规律,以便对该虫的危害盛期进行预测预报和采取防治措施,因而采用地统计学分析方法对不同坡向和疏密度的沙棘林中栎黄枯叶蛾低龄幼虫的空间分布格局进行了研究。结果表明:栎黄枯叶蛾卵孵化高峰期为6月中旬。通过全方向的变异函数曲线分析得知:阴坡密林、阴坡疏林、阳坡密林、阳坡疏林中,栎黄枯叶蛾低龄幼虫空间依赖范围分别为19.96、9.45、20.75、13.48 m,空间变异值分别为0.692、0.613、0.679、0.597。密林样地的半变异函数最佳拟合模型均为高斯模型,疏林样地均为指数模型,两种模型均指明栎黄枯叶蛾低龄幼虫的空间分布格局为聚集分布。引起种群聚集的原因主要为其生物学特性。用Kriging插值方法生成的空间分布图显示低龄幼虫在空间分布上存在明显的边缘效应。     

The distribution and density of a lycaenid butterfly in relation to Lasius ants

Summary Larvae and pupae of lycaenid butteflies are often associated with ants: this is usually a mutualism in which ants guard the lycaenids from natural enemies, and the lycaenid larvae and pupae provide sugars and amino acids for the ants. A possible consequence of the interaction is spatially correlated ant and lycaenid distributions, but the phenomenon is poorly documented. We examined the lycaenid Plebejus argus, which is tended by Lasius ants. Within habitat patches, P. argus eggs, larvae and pupae were all spatially associated with Lasius. On a larger scale, the densities of butterflies in different habitat patches and populations, and whether the butterfly was present or not, were correlated with Lasius ant densities. The association of P. argus with Lasius ants is consistent among populations, and occurs at several spatial scales. Other aspects of the ecology of P. argus are more variable.     

Survey for natural enemies of the invasive alien chrysomelid, Diabrotica virgifera virgifera, in Central Europe

The western corn rootworm, Diabrotica virgifera virgifera LeConte(Coleoptera: Chrysomelidae), is the mostdestructive pest of maize (Zea mays L.)in North America, and began to successfullyinvade Central Europe in the early 1990's. Thispaper reports a three-year field surveyconducted in Hungary, Yugoslavia, and Croatia,which are currently the focal points ofinvasion, with the aim to determine theoccurrence of indigenous natural enemies ofD. v. virgifera in Europe. A total of9,900 eggs, 550 larvae, 70 pupae and 33,000adults were examined for the occurrence ofparasitoids, nematodes, and fungal pathogens. It can be concluded from the survey resultsthat effective indigenous natural enemies arenot attacking any of the life stages of D.v. virgifera in Europe. The exception is theoccurrence of the fungi Beauveriabassiana (Bals.) Vuill. (Mitosporic fungi;formerly Deuteromyces) and Metarhiziumanisopliae (Metsch.) Sorok (Mitosporic fungi)attacking adults of D. v. virgifera at anextremely low level (< 1%). However no otherentomopathogenic fungal pathogens,entomopathogenic nematodes, or parasitoids werefound on eggs, larvae, pupae or adults. Whileseveral natural enemies in North and CentralAmerica are known to attack D. v.virgifera, it is apparent that indigenousnatural enemies in Europe have not adapted tothe high population density of the alieninvasive species D. v. virgifera. Classical biological control may provide anopportunity to reconstruct the natural enemycomplex of an invading alien pest, and itsapplication to manage D. v. virgiferapopulations in Europe should be considered.     

小菜蛾幼虫偏好表达的microRNA鉴定及功能研究

[目的]microRNA(miRNA)在昆虫生长发育中发挥重要功能,本研究拟通过鉴定小菜蛾不同发育阶段的miRNA,挖掘幼虫偏好表达的miRNA及其潜在功能.[方法]对小菜蛾卵、3龄幼虫、蛹和成虫的miRNA开展高通量测序,结合生物信息学分析方法,筛选在幼虫期偏好表达的miRNA;借助实时荧光定量PCR技术,验证候选m...     

Distribution of Boros schneideri (Panzer, 1796) (Coleoptera, Boridae) in Lithuania

The distribution of the endangered species Boros schneideri was studied by checking the presence of larvae and adults under the bark of dead Pinus sylvestris trees in 13 pine forests in Lithuania. B. schneideri was found in 10 biggest pine forests, the area of which exceeded 20,000 ha. However, it was not detected in smaller isolated forests. In Kazlų Rūda, Šimonys, Pabradė and Rūdiškės forests this species was recorded for the first time. The part of localities in which B. schneideri was found and the percentage of trees with B. schneideri were significantly higher in the main parts of the biggest forests than in satellite or smaller forests. Both these parameters were significantly lower in forests located in the close vicinity of urban territories than in forests further from them. Consequently, the forest size and the distance of the forest from urban territories were found to be of critical importance for the survival and density of the B. schneideri population. These distribution regularities are important for the establishment of protected areas for this species conservation.     

Life table and predation of Oligota pygmaea (Coleoptera: Staphylinidae) a major predator of the red spider mite, Oligonychus coffeae (Acarina: Tetranychidae) infesting tea

The staphylinid beetle, Oligota pygmaea (Solier) is an important predator of the red spider mite, Oligonychus coffeae (Nietner) infesting tea. Biology, life table and predatory efficiency of O. pygmaea were studied under laboratory conditions. Duration of developmental stages of O. pygmaea was 3.2, 5.7 and 12.5 d for eggs, larvae and pupae, respectively with an average of 23.0 d from egg to adult emergence. After a mean preovipostion period of 2.9 d, each female laid an average of 400.5 eggs in its life span. Adult O. pygmaea lived for an average of 54.1 d. Adult females lived for a longer period of 58.8 d compared to the longevity of 49.4 d of adult male. Studies revealed that its life table characterized by an intrinsic rate of natural population increase (r) of 0.118 d, net reproductive rates (R_o) of 243.693 eggs/female, gross reproduction rate (Σm_x) of 245.313 eggs/female, generation time (T) of 46.575 d, doubling time (DT) of 5.874 d and finite rate of increase (λ) of 1.125 d. Seasonal abundance of O. pygmaea and its prey, O. coffeae was monitored by sampling 25 tea leaves randomly from each experimental block grown under the prevailing field conditions. O. pygmaea showed a typical pattern of population dynamics with a peak during January to March and low incidence during June to September. Peak in the population of O. pygmaea coincided with the abundance of O. coffeae in the tea fields. Weather factors such as high temperature, low relative humidity and low sunshine hours adversely affected the populations of O. pygmaea. The first to third instar larvae of O. pygmaea consumed 31.0–133.2 eggs of mites per day. Third instar larva of O. pygmaea consumed an average of 133.2 eggs, 46.4 hexapod larvae, 39.6 nymphs and 11.4 adults per day. Adult females consumed more number of red spider mites compared to the males.