Facultad de Ciencias, Departamento de Ciencias Básicas, Universidad del Bío-Bío, Chillán, Chile.
Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Canada.
PLoS One. 2023 Jul 13;18(7):e0278427. doi: 10.1371/journal.pone.0278427. eCollection 2023.
Living in environments whose ecologies vary in periods as short as 24 h is a challenge for animals as Drosophila species that inhabit pear and apple orchards. These orchards have sunny and shady sections. The size and shape of these habitats change daily according to the position of the sun in the sky. Sunny areas are related to dryness and water loss, and shady places have lower temperatures and higher humidity. The presence of heterospecific flies may lead to competition for space and food. In sunny habitats we did not find adult Drosophila. In shady sections we found conspecific groups D. melanogaster, D. simulans, D. immigrans, D. subobscura, and the Chilean endemic D. pavani perched on grasses and herbs at 8-10 cm from fruits that had fallen on the ground. In the fruits, 99% of the adults were females and they were not grouped. The way in which daily changes in the size and shape of shady habitats together with the presence of heterospecific adults influence the selection of places to live is poorly understood in Drosophila. Our experiments show that adults of the five species prefer dark areas. The experimental results show that the odors of each species: i) influence conspecifics to select similar perch sites and decrease mobility, and ii) increase mobility in heterospecific adults and modify their perch site preferences. Attractions between conspecifics, the repulsions between species, and preferences for shaded areas matter in choosing a place to live in the five Drosophila species. These behaviors seem to have evolved as coordinated routines, contributing to the coexistence of the five Drosophila species in the apple and pear orchards examined.
生活在生态环境每天都在发生变化的环境中，对栖息在梨园和苹果园中果蝇物种等动物来说是一个挑战。这些果园有阳光充足和阴凉的区域。这些栖息地的大小和形状每天都根据天空中太阳的位置而变化。阳光充足的地区与干燥和水分流失有关，阴凉的地方温度较低，湿度较高。异源苍蝇的存在可能导致对空间和食物的竞争。在阳光充足的栖息地，我们没有发现成年果蝇。在阴凉的地方，我们发现了同种果蝇群体，如 D. melanogaster、D. simulans、D. immigrans、D. subobscura 和智利特有种 D. pavani，它们栖息在离落在地上的果实 8-10 厘米高的草丛和草本植物上。在果实中，99%的成虫是雌性，它们没有成群。在果蝇中，栖息地的大小和形状的日常变化以及异源成虫的存在如何影响栖息地的选择，这方面的知识还很缺乏。我们的实验表明，五种果蝇的成虫更喜欢黑暗的区域。实验结果表明，每个物种的气味：i）影响同种果蝇选择相似的栖息点并降低移动性，ii）增加异源成虫的移动性并改变它们对栖息点的偏好。同种个体之间的吸引力、物种之间的排斥力以及对阴凉区域的偏好，都对这五种果蝇选择栖息点起着重要作用。这些行为似乎是作为协调的例行程序进化而来的，有助于这五种果蝇在我们所研究的苹果和梨园中共存。
