纵坑切梢小蠹对云南松蛀害研究

在昆明地区,纵坑切梢小蠹Tomicus piniperda L.表现出枝梢聚集、树干蛀害等重要的行为学特征,形成三种基本蛀害模式。横坑切梢小蠹、蓝色伴生真菌参与了纵坑切梢小蠹危害过程,并在其中发挥积极作用。上述因素的综合影响,加强了纵坑切梢小蠹对云南松Pinus yunnanensis寄主树木的危害能力。     

云南横坑切梢小蠹生物学研究

横坑切梢小蠹Tomicus minor (Hartig)是云南松Pinus yunnanensis Franchet的主要次期性害虫之一。1980年以来,该虫与纵坑切梢小蠹T. piniperda（L.）一起在中国西南部大量发生,导致数十万公顷云南松林受害。本文报道了横坑切梢小蠹在云南地区的生活史、生长、发育、繁殖等生物学特征。横坑切梢小蠹年生活史为一代,前后两代在冬春季有部分重叠。成虫羽化于4月下旬开始陆续,5 月下旬结束。成虫羽化后即飞到树冠上蛀食枝梢,直到11月发育成熟,开始繁殖。在此期间,每头成虫可以蛀食4～6个枝梢。横坑切梢小蠹在云南没有越冬习性。繁殖期从11月至次年3月。成虫主要在已经受到纵坑切梢小蠹危害的树木的中、下部产卵。繁殖期较纵坑切梢小蠹约迟1周。由于横坑切梢小蠹从枝梢到树干对云南松持续危害,对树木的危害性较在其它地区更为严重。横坑切梢小蠹利用受到纵坑切梢小蠹蛀害的树木繁殖产卵,加强了蠹虫对云南松树的危害,加速了受害树木的死亡进程。横坑切梢小蠹的上述生物生态学特征是该虫对云南松造成严重危害的重要原因。从横坑切梢小蠹虫体和虫坑中检测到伴生真菌云南半帚孢Leptographium yunnanensis。横坑切梢小蠹对该菌的带菌率在蛀梢期为11.5%;在蛀干中期约为10%～26%。     

纵坑切梢小蠹蛀梢期空间分布

在昆明地区,纵坑切梢小蠹(Tomicus piniperda)成虫蛀梢多集中在蛀干木附近。 种群密度以蛀干木为中心向周围呈指数递减,散布半径约30m。在蛀梢过程中,该种群逐渐向新区扩张。在树冠内,纵坑切梢小蠹主要分布在4-10轮枝上。第7轮枝虫口百分率最高。6-7轮枝受害率最大。 树冠上层受害较其下层严重。从树冠水平层次考察,树冠外层虫量相对集中,约为树冠中、内层虫量之和。 树冠内层虫量最少。纵坑切梢小蠹在树冠内的种群分布系由梢径、种群密度、蛀梢行为、降落方式、光照等因素综合影响的结果。     

云南切梢小蠹对云南松树的蛀干危害及致死机理

蛀干危害是云南切梢小蠹致死云南松树的关键环节。通过控制云南切梢小蠹蛀干密度,对云南切梢小蠹在自然条件下蛀干行为与危害进行了首次探讨。结果表明,云南切梢小蠹蛀干密度与云南松存活率呈负相关,蛀干密度直接决定云南松死亡或存活。研究发现,蛀干密度115坑/m2是云南松树的最低致死密度阈值,云南松树在蛀干密度低于26.4坑/m2情况下存活,在26.4-115坑/m2有部分存活,超过115坑/m2以后将被害致死。云南切梢小蠹对树干攻击形成有卵和无卵两类坑道。形成无卵坑道的蛀干攻击可导致树势衰弱,形成有卵坑道的蛀干危害严重破坏了韧皮组织,是导致云南松死亡的直接原因。     

纵坑切梢小蠹蛀梢期生物学研究

本文研究了纵坑切梢小蠹Tomiaus piniperda对云南松枝梢的危害,并对该虫在蛀梢期的有关生物学特性,如性比、交配、食物选择、卵巢发育、越冬等进行了探讨。在昆明地区,蛀梢期从当年5月持续到次年3月。在此期间,该虫平均可蛀害3-6个枝梢。受害梢以当年生枝梢为主,平均直径为7-8.5mm。同一枝梢可受到多次蛀害。侵入孔距枝梢末端约3～4cm。该虫在蛀梢期已开始交配活动。交配率随卵巢发育进度而增大。各虫态受冬季气温低的影响发育减缓,但均能顺利越冬。     

纵坑切梢小蠹携带云南半帚孢研究

云南半帚孢 (Leptogramphyunnanensis)是纵坑切梢小蠹Tomicuspiniperda重要的共生真菌 ,在纵坑切梢小蠹危害寄主树木过程中发挥着重要作用。研究揭示 ,纵坑切梢小蠹主要通过与受到感染云南半帚孢的韧皮组织的接触携带上云南半帚孢的。纵坑切梢小蠹卵、幼虫和蛹对云南半帚孢的带菌率较高 ,均大于 90 % ,而成虫的带菌率较低。纵坑切梢小蠹的体表和体内均携带有云南半帚孢 ,但体表带菌是纵坑切梢小蠹带菌的主要途径。通过对纵坑切梢小蠹成虫头、足、翅和腹部带菌率的研究发现 ,云南半帚孢在纵坑切梢小蠹各部位的分布大体相同 ,揭示纵坑切梢小蠹没有携带云南半帚孢的特化构造或器官。     

纵坑切梢小蠹蛀梢期空间分布

在昆明地区,纵坑切梢小蠹（Ｔｏｍｉｃｕｓ　ｐｉｎｉｐｅｒｄａ）成虫蛀梢多集中在蛀干木附近。种群密度以蛀干木为中心向周围是指数递减,散布半径约３０ｍ。在蛀虹梢过程中,该种群逐渐向新区扩张。在树冠内,纵坑切梢小蠹主要分布在４—１０轮枝上。第７轮技虫口百分率最高。６—７轮枝受害率最大。树冠上层受害较其下属于重。从树冠水平层次考察,树冠外层虫量相对集中,约为树冠中、内层虫量之和。树冠内层虫量最少。纵坑切梢小蠹在树冠内的种群分布系由梢径、种群密度、蛀梢行为、降落方式、光照等因素综合影响的结果。     

纵坑切梢小蠹对云南松枝梢提取物趋性测试

纵坑切梢小蠹ＴｏｍｉｃｕｓｐｉｎｉｐｅｒｄａＬ .是松科树木的蛀食性害虫。在过去近 2 0多年中 ,该虫已毁灭云南松林 2 0余万ｈｍ2 ,成为目前云南森林的第一大虫害[1] 。在云南 ,纵坑切梢小蠹常年在云南松 (Ｐｉ ｎｕｓｙｕｎｎａｎｅｎｓｉｓ)枝梢内或树皮下蛀食生活 ,活动     

两种切梢小蠹危害云南松的时空生态位

【目的】云南切梢小蠹Tomicus yunnanensis KirkendallFaccoli和横坑切梢小蠹Tomicus minor(Hartig)是中国云南地区两种危害松属Pinus L.植物的钻蛀性害虫,常在云南松Pinus yunnanensis Faranch.上共同危害,通过蛀梢和蛀干为害造成树木衰弱死亡,生态破坏,带来经济损失。【方法】通过样地调查和树木解析,对两种小蠹在"梢转干"及"干转梢"时期的时间和空间生态位进行了研究。【结果】"梢转干"时期之后,横坑切梢小蠹主要分布在主干中下部,云南切梢小蠹分布在主干中上部;侧枝上主要分布着云南切梢小蠹,而横坑切梢小蠹数量很少;5月中旬进入"干转梢"阶段,两种小蠹同时进入羽化期,云南切梢小蠹在6月1日左右到达羽化高峰期,横坑切梢小蠹则比其晚10 d左右到达羽化高峰期;两种小蠹成虫转梢危害后随机分布。两种小蠹的时间和空间生态位宽度均较大,发生期较长,在云南松上分布范围较广。两种小蠹空间生态位重叠较小,在云南松上的分布趋于分离,对空间资源的需求具有较大差异;而时间生态位重叠较大,在云南松的生长季节能同时危害,且发生期较一致,危害期长。【结论】两种小蠹在空间生态位上的种间竞争强度较小,而在时间生态位上的竞争较大。通过研究比较两种切梢小蠹时间及空间生态位的特性及差异,为遥感监测云南松林的生物灾害提供了支撑依据。     

云南松林两种切梢小蠹成虫蛀梢期的空间分布格局

【目的】云南松Pinus yunnanensis Faranch是我国西南地区的重要造林绿化树种。近年来,云南省祥云县云南松林受到云南切梢小蠹Tomicus yunnanensis KirkendallFaccoli和横坑切梢小蠹Tomicus minor Hartig的共同危害。本文对两种害虫在蛀梢期的危害特性和空间分布进行了研究,以期为切梢小蠹的发生监测及防治提供依据。【方法】利用地统计学方法分析不同受害程度云南松林内两种切梢小蠹成虫蛀梢期的空间分布特性。【结果】受害程度不同的云南松林内两种切梢小蠹的危害差异显著,轻度受害林分内受害梢率为11.38%,中度受害林分内受害梢率为36.56%,而重度受害林分则达到59.7%。分析全方向的变异函数曲线图得知,蛀梢期两种切梢小蠹在不同受害云南松林中均呈聚集分布。其中,两种切梢小蠹在不同受害林分中空间依赖范围依次是:轻度受害林分中度受害林分重度受害林分,而局部空间连续性依次是:轻度受害林分中度受害林分重度受害林分。【结论】云南松林两种切梢小蠹成虫在蛀梢期的空间分布格局为聚集分布,明确两者在该时期存在聚集危害的特性,导致云南松因树梢受到聚集危害变为衰落木,从而有利于成虫蛀干危害和繁殖。本文为探究两种切梢小蠹在云南松林中的危害机制提供理论基础,也为虫害监测及防治提供参考与技术支持。     

Attack dynamics of the pine shoot beetle, Tomicus piniperda (Col.; Scolytinae) in Scots pine stands defoliated by Bupalus piniaria (Lep.; Geometridae)

Abstract 1 After a 1‐year, extensive pine looper (Bupalus piniaria) outbreak, plots were laid out to study tree susceptibility to attack, and performance of Tomicus piniperda in pine trees suffering from varying levels of defoliation. 2 Tomicus piniperda was the dominating stem‐attacking species among the primary stem colonizers, and 82% of all trees that died had been colonized by T. piniperda. 3 Beetle attacks primarily struck severely defoliated trees, i.e. trees that suffered from 90% to 100% defoliation. 4 Beetle attacks peaked in the second year after cessation of the outbreak, and suppressed trees were both more frequently attacked and more susceptible to beetle attack than intermediate and dominant trees. 5 Trees surviving beetle attacks carried more foliage than trees that did not survive the attacks. 6 A single year of severe defoliation is enough to render pine trees susceptible to secondary pests, such as T. piniperda.     

Impacts of Tomicus minor on distribution and reproduction of Tomicus piniperda (Col., Scolytidae) on the trunk of the living Pinus yunnanensis trees

This study investigated the impacts of Tomicus minor on Tomicus piniperda when the two Tomicus species coexist in the trunks of living Yunnan pine (Pinus yunnanensis L.) trees growing in the Kunming region, in south-western China. Tomicus piniperda mostly locates in the mid- and upper trunks of Yunnan pine tree; whereas T. minor mainly attacks the mid- and lower trunks. In the mid-trunk area from 1.0 to 5.0 m above ground, there are overlapping attack zones for the two Tomicus species, which accounts for an average of 80% of the entire zone occupied by T. piniperda and an average of 70% of the zone occupied by T. minor. In correspondence with their attack distributions, the average attack densities of the two species varied with height along the trunk, with 165.3 egg galleries per m² at a height of 6 m for T. piniperda, and 138.2 egg galleries per m² at the 1 m height for T. minor. It is suggested that T. minor adjusts its attack pattern with respect to T. piniperda, and thereby minimizes interspecific competition. No remarkable difference of average T. piniperda egg gallery length was found between the zone in which only T. piniperda occurred and the zone in which T. piniperda and T. minor coexisted; this is suggested to be due to low host quality in the upper trunk region where only T. piniperda was present. The number of T. piniperda larval galleries was highest when only T. piniperda was present, and decreased as T. piniperda and T. minor coexisted, particularly in the case when the density of T. piniperda was less than that of T. minor. Average larval density was 1649 larval galleries per m² where only T. piniperda occurred. However, when T. piniperda coexisted with T. minor, T. piniperda larval density averaged 1010 per m² when T. piniperda density was higher than T. minor, and averaged 442 per m² when T. piniperda density was less than T. minor, which led to the conclusion that T. minor makes a negative impact on T. piniperda reproduction when the two Tomicus species jointly colonize the same trunk of Yunnan pine tree.     

Shoot feeding ecology of Tomicus piniperda and T. minor (Col., Scolytidae) in southern China

Abstract: The pine shoot beetle, Tomicus piniperda, is causing substantial tree mortality to Pinus yunnanensis in south‐western China, whereas the same species in Europe seldom kills Pinus sylvestris. In order to understand this difference in aggressiveness, we studied the shoot feeding ecology of the pine shoot beetles in Yunnan, and compared it with European results. We found many similarities in the shoot feeding behaviour of T. piniperda, and also that of Tomicus minor, which was common locally. In contrast to Europe, however, the pine shoot beetles in Yunnan seem to be able to predispose the host trees for stem attack by intensive shoot‐feeding. It has also been observed that beetles aggregate in certain trees during shoot feeding, but we could not verify that in our experiment.     

Host resistance in defoliated pine: effects of single and mass inoculations using bark beetle-associated blue-stain fungi

1 In 1996, 7000 ha of pine forests were defoliated by the pine looper Bupalus piniaria in south‐western Sweden. 2 The susceptibility of trees of different defoliation classes (0, 30, 60, 90 and 100% defoliation) to beetle‐vectored blue‐stain fungi was tested in inoculation experiments. Forty and 120‐year‐old Scots pine trees were inoculated with ‘single’, i.e. a few inoculations of Leptographium wingfieldii and Ophiostoma minus, two blue‐stain fungi associated with the pine shoot beetle Tomicus piniperda. The young trees were also ‘mass’ inoculated with L. wingfieldii at a density of 400 inoculation points per m² over a 60 cm stem belt. 3 Host tree symptoms indicated that only trees with 90–100% defoliation were susceptible to the mass inoculation. 4 Single inoculations did not result in any consistent differences in fungal performance between trees of different defoliation classes, regardless of inoculated species or tree age class. 5 Leptographium wingfieldii produced larger reaction zones than O. minus, and both species produced larger lesions in old than in young trees. 6 As beetle‐induced tree mortality in the study area occurred only in totally defoliated stands, mass inoculations seem to mimic beetle‐attacks fairly well, and thus seem to be a useful tool for assessing host resistance. 7 As even severely defoliated pine trees were quite resistant, host defence reactions in Scots pine seem to be less dependent on carbon allocation than predicted by carbon‐based defence hypotheses.     

Descriptive biogeography of Tomicus (Coleoptera: Scolytidae) species in Spain

Aim, location Tomicus (Coleoptera, Scolytidae) species are some of the principal pests of Eurasian forest and are represented by three coexisting species in Spain, Tomicus piniperda (Linnaeus, 1758), Tomicus destruens (Wollaston, 1865) and Tomicus minor (Harting, 1834). The distribution of two taxa are unknown as they have until recently been considered separate species. Therefore, we model the potential distribution centres and establish the potential distribution limits of Tomicus species in Iberia. We also assess the effectiveness of different models by comparing predicted results with observed data. These results will have application in forest pest management. Methods Molecular and morphological techniques were used to identify species from 254 specimens of 81 plots. For each plot, a Geographical Information System was used to extract a set of 14 environmental (one topographic, six climatic) and biotic variables (seven host tree distributions). General Additive Models and Ecological Niche Factor Analysis models are applied for modelling and predicting the potential distribution of the three especies of Tomicus. Results The results of both modelling methodologies are in agreement. Tomicus destruens is the predominant species in Spain, living in low and hot areas. Tomicus piniperda occurs in lower frequency and prefers wet and cold areas of north‐central Spain. We detected sympatric populations of T. destruens and T. piniperda in Northern coast of Spain, infesting mainly P. pinaster. Tomicus minor is the rarest species, and it occupies a fragmented distribution located in high and wet areas. The remarkable biotic variable is the distribution of P. sylvestris, incorporated into the models of T. destruens and T. piniperda. Main conclusions These results indicate that in wet areas of north‐central Spain where T. piniperda occurs (and possibly the high altitudes of the southern mountains), T. destruens has a climatic distribution limit. In the northern border of this area, both species overlap their distributions and some co‐occurrences were detected. Tomicus minor potentially occurs in high and wet fragmented areas.     

Attraction of the bark beetle Tomicus piniperda to Scots pine trees in relation to tree vigor and attack density

The attraction of Tomicus piniperda (L.) (Coleoptera: Scolytidae) to Scots pine trees of low and higher vigor with and without previous attacks was monitored with sticky traps. Somewhat higher numbers of beetles were caught on low vigor trees than on trees of higher vigor, indicating differences in olfactory stimuly between the two classes of trees.Many more beetles were caught on trees attacked by T. piniperda and on trees with simulated bark beetle galleries (manually drilled holes) than on control trees with no or only a few attacks. The strong attraction of beetles to attacked trees is attributed to the beetles responding to host volatiles released from the galleries.

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Zusammenfassung Der Anflug von Tomicus piniperda (L.) (Coleoptera: Scolytidae) an Kiefern in schlechtem oder besserem Gesundheitszustand, mit oder ohne vorherigen Befall, wurde mit Hilfe von Leimfallen untersucht. An Bäumen in schlechtem Zustand wurden etwas mehr Käfer gefangen als an Bäumen in besserem Gesundheitszustand. Das deutet auf Unterschiede in Geruchsreizen zwischen den beiden Klassen des Baumzustands hin.An Kiefern, die von T. piniperda befallen waren oder simulierte Einbohrungen (von Hand gebohrte Löcher) hatten, wurden viel mehr Käfer gefangen als an Kontrollbäumen ohne oder mit sehr geringem Befall. Der starke Anflug von Käfern an befallene Bäume wird gedeutet als Reaktion auf Duftstoffe des Wirts, die aus den Borkenkäfergängen abgegeben werden.

     

Interactions between the phloem-feeding speciesTomicus piniperda (Col.: Scolytidae) andAcanthocinus aedilis (Col.: Cerambycidae), and the predatorThanasimus formicarius (Col.: Cleridae) with special reference to brood production

Interactions betweenTomicus piniperda (L.) (Col.: Scolytidae),Acanthocinus aedilis (L.) (Col.: Cerambycidae) andThanasimus formicarius (L.) (Col.: Cleridae) were investigated in caged pine bolts. The treatments wereT. piniperda alone,A. aedilis alone,T. piniperda together withA. aedilis, T. piniperda together withT. formicarius and all three species together. T. piniperda offspring production per m² was reduced by 92% when reared withT. formicarius, by 78% when reared withA. aedilis, and by 94% when all three species were reared together, compared withT. piniperda reared alone.A. aedilis had a negative influence on the offspring production ofT. formicarius and vice versa. When both species were present in the same bolt (together withT. piniperda) offspring production was reduced by 74% forA. aedilis and by 42% forT. formicarius compared with their respective production values when each species was present alone with the bark beetle. The new generation ofT. formicarius emerged as larvae from June to August while most of theA. aedilis offspring emerged as adults from September to October, leaving only a few larvae in the bolts to hibernate.A. aedilis only reproduced in a small part of one of the bolts without bark beetles.     

Evolving Management Strategies for a Recently Discovered Exotic Forest Pest: The Pine Shoot Beetle, Tomicus Piniperda (Coleoptera)

Established populations of the Eurasian pine shoot beetle (Tomicus piniperda (L.); Coleoptera: Scolytidae) were first discovered in North America in Ohio in 1992. As of 31 December 2000, T. piniperda was found in 303 counties in 12 US states (Illinois, Indiana, Maine, Maryland, Michigan, New Hampshire, New York, Ohio, Pennsylvania, Vermont, West Virginia, and Wisconsin) and in 43 counties in 2 Canadian provinces (Ontario and Quebec). A federal quarantine imposed in November 1992 regulates movement of pine (Pinus) trees, logs, and certain pine products from infested to uninfested areas within US. The forest products, Christmas tree, and nursery industries are affected by the quarantine. This paper summarizes information on the discovery and spread of T. piniperda in North America, survey efforts, recent interception history, development and changes in the federal quarantine, development of a national compliance management program, and extension and research efforts.