Keesey Ian W, Knaden Markus, Hansson Bill S
Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745, Jena, Germany,
J Chem Ecol. 2015 Feb;41(2):121-8. doi: 10.1007/s10886-015-0544-3. Epub 2015 Jan 25.
It has been demonstrated that Drosophila suzukii is capable of attacking ripening fruit, making it a unique species within a fly family named for their attraction towards the fermentation products associated with rotten fruits, vinegar, and yeast. It also has been hypothesized that D. suzukii is more attracted to the volatiles associated with the earlier ripening stages of fruit development, and in turn, that D. suzukii is less attracted to fermented food resources, especially when compared with D. melanogaster. Here, we demonstrate that D. suzukii and its close relative D. biarmipes are in fact more sensitive to volatiles associated with the fruit-ripening process; however, in choice-assays, both spotted-wing species are more attracted to fermented fruit than to earlier stages of fruit development, which is similar to the behavioral preferences of D. melanogaster, and thus, fruit developmental stage alone does not explain the ecological niche observed for D. suzukii. In contrast, we show that both D. suzukii and D. biarmipes are more attracted to leaf odors than D. melanogaster in behavioral trials. For D. suzukii, this differential behavioral preference towards leaves appears to be linked to β-cyclocitral, a volatile isoprenoid that we show is most likely a novel ligand for the "ab3A" neuron. In addition, this compound is not detected by either of the other two tested fly species.
已有研究表明，铃木氏果蝇能够攻击成熟果实，这使其在一个以对与腐烂果实、醋和酵母相关的发酵产物有吸引力而闻名的果蝇科中成为独特的物种。也有人推测，铃木氏果蝇对与果实发育早期成熟阶段相关的挥发物更有吸引力，反之，铃木氏果蝇对发酵食物资源的吸引力较小，尤其是与黑腹果蝇相比。在此，我们证明铃木氏果蝇及其近亲双带果蝇实际上对与果实成熟过程相关的挥发物更敏感；然而，在选择试验中，这两种斑翅果蝇对发酵果实的吸引力比对果实发育早期阶段的吸引力更大，这与黑腹果蝇的行为偏好相似，因此，仅果实发育阶段并不能解释铃木氏果蝇所观察到的生态位。相比之下，我们在行为试验中表明，铃木氏果蝇和双带果蝇对叶片气味的吸引力都比黑腹果蝇更大。对于铃木氏果蝇来说，这种对叶片的不同行为偏好似乎与β - 环柠檬醛有关，我们发现这种挥发性类异戊二烯很可能是“ab3A”神经元的一种新型配体。此外，另外两种受试果蝇物种都未检测到这种化合物。
