圆唇散白蚁雌性补充生殖蚁不同发育阶段表皮长链碳氢化合物的变化

Variations of cuticular long-chained hydrocarbons in different developmental stages of female neotenic reproductives of the subterranean termite Reticulitermes labralis( Isoptera: Rhinotermitidae)

【目的】确定圆唇散白蚁Reticulitermes labralis补充生殖蚁不同发育阶段表皮长链碳氢化合物（cuticular longchained hydrocarbons,CHCs）的变化。【方法】人工隔离巢群饲养圆唇散白蚁R.labralis,观测其翅芽型补充生殖蚁的分化时间和补充生殖蚁数量趋于稳定的时间,并采用气质联用仪（GC-MS）对补充生殖蚁不同发育阶段的表皮长链碳氢化合物变化趋势进行分析。【结果】随着补充生殖蚁的出现,每一巢群会逐渐形成稳定数量的具有生殖能力的生殖蚁。若蚁在分化为补充生殖蚁的第8天时,43.3%的组补充生殖蚁数量趋于稳定,第16天时83.3%的组趋于稳定,第25天时93.3%的组趋于稳定,36 d后100%的组趋于稳定。通过补充生殖蚁不同发育阶段中CHCs各峰面积与若蚁阶段相应峰峰面积的比值随发育阶段的变化趋势分析发现,在卵中没有检测到的保留时间为38.52min的化合物在补充生殖蚁产7~8粒卵时峰面积比值是若蚁阶段的14.14倍;在卵中检测到的保留时间为35.50和39.21 min的峰面积比值在补充生殖蚁开始产卵后显著升高。【结论】CHCs不能用来区分有无生殖能力的补充生殖蚁个体,但可以很好地用来区分补充生殖蚁个体与尚未转化为生殖蚁的若蚁个体;保留时间为38.52 min的化合物是补充生殖蚁的特有物质;保留时间为35.50和39.21 min的化合物可作为补充生殖蚁已经产卵的标志。

【Aim 】 This study aims to find the time of establishment and maintenance of dominant reproductive status and the variations of relevant cuticular long-chained hydrocarbons（ CHCs） in neotenic reproductives of Reticulitermes labralis. 【Methods】Orphaned colonies of R. labralis were established in the laboratory. The time of establishment and maintenance of stable reproductive status for neotenic reproductives was determined via the differentiation observation. The variations of relevant CHCs in different developmental stages of neotenic reproductives were analyzed with gas chromatography-mass spectrometer（ GC-MS）. 【Results】With the appearance of neotenic reproductives of R. labralis,each colony gradually had its dominant reproductives（ stable reproductives）. Colonies with stable reproductives accounted for 43. 3%,83. 3%,93. 3% and 100% of the orphaned groups on the 8th,16 th,25th and 36 th day,respectively. By analyzing the peak area ratios（ the peak area at each stage divided by the area of the corresponding peak at the nymphal stage） in different stages of neotenic reproductives,we found that the peak area ratio of the compound with the retention time of 38. 52 min,which was not detected in eggs,was 14. 14 times in reproductives laying 7- 8 eggs as high as that in the nymphal stage,while the compounds with the retention time of 35. 50 and 39. 21 min,which were detected in eggs,had significantly increased peak area ratios after the reproductives began to lay eggs.【Conclusion】CHCs can not be used to discriminate fertile neotenics（ neotenic reproductives that establish and maintain dominant reproductive status） from infertile neotenic reproductives（ individualswith morph of neotenics,but unable to lay eggs in the colony） of R. labralis,although they can be used to discriminate neotenic reproductives from nymphs easily. The compound with the retention time of38. 52 min is a characteristic substance of reproductives. The compounds with the retention time of 35. 50 and 39. 21 min are characteristic substances of neotenic reproductives that have laid eggs.