摘要
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。
n Kunming, Tomicus piniperda (L.) during the period of shoot feeding distributed mainly around the host trees in which the trunks had been used as the reproduction site. Around all these trees the population density decreased exponentiallyfrom the centre to the periphery. The diameter of dispersion area was about 30m.During shoot feeding, the beetle population dispersed into the new area around progressively. In the crown of host tree, the bark beetles distributed principally to4th-10th whorls. The percentage of the bark beetles in the crown reached thelargest in the 7th whorl. The rate of shoot damaged was the largest in the 6th-7thwhorls, followed in the second place in 2th--5th whorls, and decreased progressively from the 7th to the lowest whorl. At the levels in the crown, the barkbeetles concentrated relatively in the outer portion of the crown, which was aboutthe sum of the numbers in the middle and inner portions of the crown. In the early period of shoot feeding, the population distributed mainly in the outer portionof the crown, and then progressively dispersed to the middle and the inner portionsof the crowns. In the late period of shoot feeding, most of population aggregatedin the crowns of the trees which whould be attacked on the trunks, and distributedmainly in the outer portions of these crowns. On the basis of comprehensive analysis,the spatial distribution of the bark population in the crown is thought to be theresult from the influence of the shoot diameter, the population density, tranferringdamage, landing behavior, and sunlight on the bark beetle behavior.
出处
《昆虫学报》
CAS
CSCD
北大核心
1994年第3期311-316,共6页
Acta Entomologica Sinica
关键词
纵坑切梢小蠹
蛀梢
云南松
分布
Tomicus piniperda (L.) --shoot feeding --Yunnan pine--spatial distribution
