竞争效应对红色型豌豆蚜繁殖的影响

Effect of Competition on Reproduction of Pea Aphid(Red Morph)

为明确种间竞争和种内竞争效应对红色型豌豆蚜生长和繁殖产生的影响,本研究以红色豌豆蚜克隆、绿色型豌豆蚜克隆及豌豆修尾蚜克隆作为试验材料,选用琼脂法,首先制备4种竞争试验区(1头区,2头区,种内竞争区和种间竞争区),观察各试验区蚜虫的种群动态,另准备3个(红色型、绿色型及豌豆修尾蚜)高密度种群处理,分别往里放入1头4龄红色克隆若虫,统计其3日总产蚜数。结果发现,种内竞争区和种间竞争区,二者的竞争效应都非常明显,竞争区混合种群的增殖率高于2头区,种间竞争区红色克隆胜利组单头红色克隆第10天新生蚜数高于其他处理。此外,高密度的绿色克隆和豌豆修尾蚜种群均能抑制红色克隆的繁殖。因此,红色型豌豆蚜能通过评估竞争种和同伴的相对密度来控制繁殖,无论是种间竞争还是种内竞争均能影响其繁殖,且种间竞争可能加速它的繁殖速率。

This study was carried out to clarify the effects of interspecific and intraspecific competitions on the growth and reproduction of red morph(A.pisum).Firstly,4 treatments(a single aphid,two aphids,intraspecific competition treatment,and interspecific competition treatment)were adopted by using clones of A.pisum red morph,A.pisum green morph and Megoura crassicauda,and the populational dynamics of aphids in each treatment were evaluated based on the agar method.A 4 th-instar A.pisum red morph was placed into three high-density populations of A.pisum red morph,A.pisum green morph and M.crassicauda respectively,and their offspring number was counted within 3 days after larviposition.The results showed that the competitive effects were observed in both intraspecific and interspecific competition treatments,as higher reproduction rate was found in mixed populations with the competition treatments than that in the two-aphids treatment.It revealed that more newborn aphids on day 10 were found in the interspecific competition group with a victory of red clone,compared to those in the other groups.In addition,both A.pisum green morph and M.crassicauda populations of high density suppressed the reproduction of red clones.These results indicated that the reproduction of A.pisum red morph depended on the relative densities of competition species individuals and their mates,and both interspecific and intraspecific competitions could affect its reproduction,especially with reproductive rate accelerated by interspecific competition.