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。     

为害云南松的纵坑切梢小蠹 (Tomicus piniperda)经济阈值的研究(英文)

经过对纵坑切梢小蠹 (TomicuspiniperdaL .)种群密度和云南松 (PinusyunnanensisFranch .)生长状况的长期、仔细的调查 ,加上改进的回归分析方法 ,得出了为害云南松的纵坑切梢小蠹防治上的经济阈值 :当林木枯死率不超过 0 .5 2 %时 ,自然控制因子能控制纵坑切梢小蠹种群不向高密度方向发展 ,因而可以不必防治。当林木枯死率达到 0 .5 0 % ,对应的枯捎率为 0 .6 1 % ,以及对应的平均每株侵入孔数为 0 .6 6时 ,防治费用和挽回损失价值相当。所以 ,若既考虑到经济上的合理性 ,又考虑到控制其种群不向高密度方向发展 ,当林木枯死率超过 0 .5 % ,对应的枯梢率超过 0 .6 1 % ,以及对应的平均每株侵入孔数超过 0 .6 6时 ,就有了进行防治的必要。本文还给出了各云南松林区可以用来根据自己的具体情况计算出适合自己的经济阈值的公式。     

THE STUDY OF THE ECONOMIC THRESHOLD OF TOMICUS PINIPERDA (COLEOPTERA: SCOLYTIDEA) ON YUNNAN PINE

Abstract By careful and long period field investigation of the population density of Tomicus piniperda L. and the growth of Yunnan pine ( Pinus yunnanensis French.), and improved regression analysis, the economic threshold of Tomicus piniperda on Yunnan pine is determined: When the death rate of the trees is not more than 0.52%, the natural control factors can prevent the density of the bark beetle from increasing and no control measure is needed. When the death rate of the trees reaches 0.5%, the corresponding rate of shoots attacked is 0.61% and the mean of invading holes per tree 0.66, the cost for control is equal to the economic loss saved. So, considering both the economic justification and the prevention of the pest density from increasing, when the death rate of the trees is more than 0.5%, the corresponding rate of shoots attacked more than 0.61% and the mean of invading holes per tree more than 0.66, control measure should be taken. The paper also gives formulae for different Yunnan pine forest areas to calculate their own economic threshold according to their special situations.     

Genetic study of the forest pest Tomicus piniperda (Col., Scolytinae) in Yunnan province (China) compared to Europe: new insights for the systematics and evolution of the genus Tomicus

The pine shoot beetle Tomicus piniperda is present throughout Eurasia. In Europe, it is considered as a secondary pest that rarely causes tree mortality, while heavy damage is observed in Yunnan Province (China) where it exhibits a novel aggregative behaviour during shoot attack. To understand why the ecological characteristics of the European and Chinese populations differ so strongly, we conducted an analysis of population genetic structure on 12 populations in Yunnan and one in JiLin using mitochondrial (COI-COII) and nuclear (ITS2 and 28S rDNA) DNA sequences, and compared the results to those obtained in France. We showed that the Yunnan populations differed markedly from French and JiLin populations. For all three markers, the genetic distances measured between the Tomicus from Yunnan and those from France were similar to distances previously observed between species. Similar distances were found between Yunnan and JiLin populations. Conversely, the distances between French and JiLin individuals were substantially lower, falling in the intraspecific range. We concluded that the individuals sampled in Yunnan belong to a new, undescribed species (Tomicus sp. nov.). We also showed that some individuals belong to the species T. brevipilosus that had never been recorded from this region before. Evolution of the genus Tomicus is discussed in the light of these new results.     

Induced defence reaction in Scots pine following stem attacks by Tomicus piniperda

The induced defence reaction of Scots pine Pinus sylvestris to stem attacks by the common pine shoot beetle, Tomicus piniperda (Col, Scolytidae), was studied by inducing natural attacks on young Scots pine trees of different vigour Pruned trees were more heavily attacked by T piniperda than unpruned ones Vigorous trees successfully contained the attacking beetles within resinous lesions, whereas less vigorous trees failed to defend themselves The content of resin acids increased dramatically in the lesions on all trees, and the resin acid composition differed somewhat between some treatments Starch accumulation in the inner bark of the main stem was lower in pruned trees than in unpruned ones, and starch reserves were depleted in the most heavily attacked trees All but one of the unpruned trees survived the attack, whereas most of the severely pruned ones died following attack by beetles at densities exceeding c 300 egg galleries m⁻²     

Fungal flora associated with Tomicus piniperda L. in an area close to a timber yard in southern Poland

Abstract:  The association between Tomicus piniperda L. (Col., Scolytinae) and fungi was studied in a Pinus sylvestris L. forest in Mielec-Mościska. Fungi were isolated from overwintered adult beetles taken from two stands situated in different distance from timber yard. Two media were used for isolation. The results showed great diversity of fungi associated with T. piniperda : 1895 cultures, representing 64 species, were isolated. Penicillia and Hormonema dematioides were the dominant species, found in 20.2% and 17.8% of all beetles, respectively. A frequently isolated ophiostomatoid fungi was Ophiostoma minus . Qualitative and quantitative differences in the mycobiota composition of this insect between two stands were detected. The highest richness and diversity of fungal species appeared in the samples taken from the location where the trees were heavily damaged by shoot-feeding of T. piniperda . Differences were most clear for the pathogenic O. minus , which was a common fungal associate of the insects in this stand.     

Tomicus piniperda (Coleoptera: Scolytidae) emergence in relation to burial depth of brood logs

The pine shoot beetle, Tomicus piniperda (L.), is an exotic pest of pines, Pinus spp., that was first found in the United States in 1992. A federal quarantine currently regulates movement of pine Christmas trees and pine nursery stock from infested to uninfested counties. The current national Pine Shoot Beetle Compliance Management Program requires T. piniperda-infested brood material to be disposed of by burning, chipping, or burial. The burial option requires that the infested pine material be buried at a depth of at least 30 cm. We tested this requirement by burying logs with similar levels of infestation at 0, 15, 30, 45, 61 and 76 cm and then monitoring for T. piniperda emergence. Logs were buried at two times during larval development (early and late) and in two soil types (sandy loam and loam). Emergence patterns from the two soil types were similar. Overall, 1,747 T. piniperda adults were collected from the 24 exposed control logs, but only 34 adults from the 120 buried logs, including 24 adults from logs buried at 15 cm, eight adults from 30 cm, one adult from 45 cm, and one adult from 61 cm. In comparing mean emergence density from buried logs with that of exposed logs, 98.6% mortality occurred at 15 cm, 99.5% at 30 cm, and > 99.9% at > or = 45 cm. Mean date of T. piniperda emergence to the soil surface was affected by burial depth and burial date, but not soil type.     

Host and non-host odour signals governing host selection by the pine shoot beetle, Tomicus piniperda and the spruce bark beetle, Hylurgops palliatus (Col., Scolytidae)

Abstract:  Tomicus piniperda and Hylurgops palliatus colonize susceptible host trees by responding to host-specific odour signals as well as by avoiding volatiles emanating from non-host conifers. In the field, the pine shoot beetle, T. piniperda , responded in high numbers to natural odour sources provided by their host tree, Pinus sylvestris , while the non-host conifers Larix decidua , Picea abies , or Pseudotsuga menziesii were significantly less attractive. In contrast, the spruce bark beetle, Hylurgops palliatus , preferentially responded to its main host, P. abies . Furthermore, T. piniperda attacks on P. sylvestris bolts decreased in presence of bark and wood particles from the non-host P. abies , whereas particles from P. menziesii appeared not to affect T. piniperda attacks. Apparently, tree-specific volatiles act at close range as specific signals that lead to the successful discrimination and colonization of the respective host tree species.