摘要
采用林间定期调查取样的方法,测定白蜡窄吉丁幼虫的龄数以及各龄的龄期;分别测量不同发育阶段幼虫的体长、体宽(第7腹节最宽处)、前胸背板宽、口缘宽、尾叉长和尾叉前缘宽等6项指标,以期找出区分和判定幼虫虫龄的最佳形态特征及指标。结果表明:白蜡窄吉丁幼虫有4龄,尾叉及其长度可作为理想的分龄特征和分龄指标;幼虫的口缘宽度也可作为指标之一;体长、体宽、前胸背板宽和尾叉前缘宽变异较大,不宜用于分龄。研究还发现:幼虫尾叉内侧的形态特征是区分幼虫虫龄的简洁而方便的方法。利用种群众数龄期法测定各龄的平均龄期分别为:1龄1 8 1d ,2龄1 1 2d ,3龄1 0 7d ,4龄2 6 1 2d ,幼虫期共为30 1 3d。
The number of larval instars and stage duration of each instar of the Emerald Ash Borer (EAB), Agrilus planipennis (Coleoptera: Buprestidae) were determined by sampling periodically in forests. Six variables including the body length, body width, width of the prothoracic plate, width of the peristoma, length of the urogomphus, and anteriormost width of the urogomphus were examined under binocular microscope with an eyepiece micrometer for choosing the optimal morphological characters or index for the separation of larval instars. Results showed that the larvae of EAB have 4 instars. The urogomphus and its length were the best characteristic and variable for the separation of larval instars, and the width of peristoma was the second best according to the overlapping degree of variable. Body length, body width, width of the prothoracic plate, and anteriormost width of the urogomphus were not reliable due to high variation. Morphological characters on the inner side of larval urogomphus are also helped to separate the instars tersely and conveniently. The average stadia based on the median value of samples was as follows: 18 1 d for the 1 st instar, 11 2 d for the 2 nd instar, 10 7 d for the 3 rd instar, and 261 2 d for the 4 th instar. The total larval stage duration was 301 3 d naturally.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2005年第3期97-102,共6页
Scientia Silvae Sinicae
基金
中美合作项目 (美国农业部林务局和动植物检疫局 )
瑞典国际科学基金 (InternationalFoundationforScience)项目 (D 36 89-1 )资助
关键词
白蜡窄吉丁
幼虫龄数
分龄指标
龄期
Agrilus planipennis
larval instars
variables for instar separation
stadia
