红树林考氏白盾蚧的初步研究

Preliminary studies on the scale insect pest of Pseudaulacaspis cockerelli in mangrove

首次发现陆生考氏白盾蚧严重为害潮间带红树植物秋茄。通过野外定位调查和室内饲养观察,研究其危害特征、种群分布、生殖力和自然死亡率。结果表明,考氏白盾蚧主要分布在秋茄叶片主脉两侧,叶背虫口数显著多于叶面(P<0.01),单叶虫口数多为1-50头,平均25.65头,最高418头;秋茄植株不同垂直空间层次的虫口密度无显著差异,但聚集度随垂直空间下降而增大;种群平均产卵量每雌52.22粒,自然死亡率69.35%,寄生蜂寄生是最主要的死亡因子,寄生率达34.23%;与几种陆生寄主植物相比,红树林考氏白盾蚧的种群密度、生殖力、叶最高虫口数均较高,该虫对潮间带生境及寄主秋茄具有适应性。

The scale insect, Pseudaulacaspis cockerelli is an important pest for many kinds of plants for a long time in the land. In 2006, it was found firstly attacking the mangrove plant of Kandelia obovata in the tideland in Xiamen City, and had led to badly damages. Based on the field surveys and lab feeding, this paper dealed with its damage characteristic, population distribution, fe- cundity and natural mortality etc. The results showed that the scale insect mainly distributed on both sides of the midvien of K. obovata leaves, but the individual on the abaxial surface was significantly more than those on the adaxial surface （P 〈 0.01 ）. The individual number of one leaf mostly fluctuated from 1 to 50, and the average and tiptop numbers were 25.65 and 418, respectively. The pest population density had no remarkable discrepancies among different vertical spatial layer of K. obovata, however, its aggregating degree increased with falling of the layer. The population had an avarage fecundity of 52.22 each female and a high natural mortality of 69.53%. The main natural death factor were two species of parasites （ Hymenoptera： Chalcididae） , and their total parasitical ra- tio reached 34.23%. In the mass, the pest population density, fecundity and tiptop individual number of a leaf in the mongrove were all more than those in serval other host plants on land, which implied that this scale insect had a high adaptability to the habitat of tideland and the plant of K. obovata.