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横坑切梢小蠹Tomicusminor (Hartig)是云南松PinusyunnanensisFranchet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Leptographiumyunnanensis。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 %～ 2 6 %。
Tomicus minorns (Hartig) is one of the major perennial pests of Pinus yunnanensis Franchet. Since 1980, the insects have been found in large quantities in southwestern China, together with T. pitiniperda (L.), which caused hundreds of thousands of hectares of Pinus yunnanensis to suffer. In this paper, we report the biological characteristics such as the life history, growth, development and reproduction of Hyphantria cunea in Yunnan Province. Cross bore pitcher Beetles annual life history as a generation, before and after two generations in winter and spring have some overlap. Adult emergence begins in late April and ends in late May. After the emergence of adults flew to the canopy on the branches, until November mature, began to breed. During this period, adults per adult can eat 4 to 6 shoots. Cross bore pit beetles do not overwinter habit in Yunnan. Breeding period from November to March next year. Adults mainly lay their eggs in the middle and lower parts of the trees that have been attacked by Pinctadae. Breeding period than the pit pitcher beetle about 1 week later. Due to the continuous cross-borer beetles from branches to the trunk of the continued damage to Pinus thunbergii, the dangers of trees more serious than in other areas. The cross-pit bark beetles breed and lay eggs by the trees that are moth-eaten by the beetles of the cellars, which enhance the harm of silver beetles to the cedar of Yunnan and speed up the process of the death of the harvested trees. The above-mentioned bioclimatic characteristics of the Baker beetle are the important causes of the serious damage to Pinus yunnanensis. Leptographiumyunnanensis, a companion fungus, was detected from the crossbreed bark beetles and the wormholes. The infestation rate of this bacterium was 11 5% at the shoot stage and 10% ~ 26% at the mid-stem stage.