Wee Suk-Ling, Tan Keng-Hong
School of Biological Sciences, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.
J Chem Ecol. 2005 Apr;31(4):845-58. doi: 10.1007/s10886-005-3548-6.
Bactrocera carambolae and B. papayae are major fruit fly pests and sympatric sibling species of the B. dorsalis complex. They possess distinct differences in male pheromonal components. In the 1990's, wild Bactrocera fruit flies with morphological traits intermediate between those of B. carambolae and B. papayae were often captured in traps baited with methyl eugenol (ME). Chemical analyses of rectal glands of ME-fed males revealed that the laboratory Fl, F2, and backcross hybrids possessed ME-derived sex pheromonal components ranging from that typical of B. papayae to that of B. carambolae without any specific trend, which included a combination of pheromonal components from both parental species within an individual hybrid. ME-fed hybrids without any ME-derived pheromonal components were also detected. Further chemical analysis of rectal glands from wild Bactrocera males, after ME feeding in the laboratory, showed a combination of pheromonal components similar to that found in the ME-fed, laboratory-bred hybrids. These findings present circumstantial evidence for the occurrence of a natural hybrid of the two Bactrocera species.
杨桃果实蝇和番木瓜果实蝇是实蝇科的主要害虫，也是同域分布的近缘种。它们在雄性信息素成分上存在明显差异。在20世纪90年代，常在用甲基丁香酚（ME）诱捕的诱捕器中捕获到形态特征介于杨桃果实蝇和番木瓜果实蝇之间的野生实蝇。对取食ME的雄性果蝇直肠腺进行化学分析发现，实验室的F1、F2和回交杂种具有源自ME的性信息素成分，其范围从典型的番木瓜果实蝇到杨桃果实蝇，没有任何特定趋势，其中包括单个杂种中来自两个亲本物种的信息素成分组合。还检测到没有任何源自ME的性信息素成分的取食ME的杂种。对在实验室中取食ME后的野生实蝇雄性直肠腺进行进一步化学分析，结果显示其信息素成分组合与在取食ME的实验室培育杂种中发现的相似。这些发现为这两种实蝇自然杂交的发生提供了间接证据。
