Abstract：
Walnut dusky-veined aphid Panaphis juglandis (Goeze) and walnut green aphid Chromaphis juglandicola (Kaltenbach) cause economic losses and co-occur on walnut trees, but they have separate niche. Panaphis juglandis feeds on the upper (adaxial) surface of leaves while C. juglandicola feeds on the lower (abaxial) surface. Field surveys and controlled experiments in the field and laboratory were conducted to determine microhabitat selection by P. juglandis and C. juglandicola and the factors associated with this behavior. In the field, the two aphid species colonized a leaflet as follows: P. juglandis only, 16.5%; C. juglandicola only, 44.5%; and both species on same leaflet, 39%. C. juglandicola settled on the abaxial surface earlier than P. juglandis settled on the adaxial surface. P. juglandis showed the highest reproduction rate when they were in the erect position on the adaxial surface. C. juglandicola exhibited the highest reproduction rate when they were inverted and on the abaxial surface. Under a light intensity of 50,000 lux, 60.5% of C. juglandicola remained on the illuminated surface, while P. juglandis did not move from the illuminated surface. Through field and laboratory experiments, we found that P. juglandis preferred to settle on the adaxial surface and C. juglandicola preferred to settle on the abaxial surface. Leaf surface, gravity, and light were three physical factors affecting microhabitat selection by the two aphid species but light intensity was the key factor. This information will help to better understand the habitats of two aphid species, which may be helpful for walnut aphids management strategies such as the usage of insecticides option and spraying.
摘要：
核桃暗纹蚜虫Panaphisjuglandis（Goeze）和核桃绿色蚜虫Chromaphisjuglandicola（Kaltenbach）造成经济损失，并在核桃树上共同发生，但是他们有独立的利基。胡枝子以叶片的上（正面）表面为食，而胡枝子在下（背面）表面为食。在野外和实验室中进行了实地调查和对照实验，以确定胡志明市和胡志明市的微生境选择以及与这种行为相关的因素。在田野里,这两种蚜虫在传单上定殖如下：仅P.juglandis，16.5%；仅限胡志明市，44.5%；两个物种在同一小叶上，39%。C.juglandicola比p.juglandis更早地沉降在背面。当它们在正面直立位置时，p.juglandis的繁殖率最高。C.juglandicola在倒置和背面时表现出最高的繁殖率。在50,000勒克斯的光强度下,60.5％的胡德兰科拉仍然在被照亮的表面上，而胡桃木没有从被照亮的表面移动。通过现场和实验室实验，我们发现P.juglandis优选沉降在正面和C.juglandicola优选沉降在背面。叶表面,重力,光是影响两种蚜虫微生境选择的三个物理因素，但光强是关键因素。这些信息将有助于更好地了解两种蚜虫的栖息地，这可能有助于核桃蚜虫的管理策略，如杀虫剂的选择和喷洒的使用。
