悬铃木方翅网蝽与红带网纹蓟马的竞争关系研究

Studies on the competitive relationship between Corythucha ciliata and Selenothrips rubrocinctus

【背景】悬铃木方翅网蝽是仅危害悬铃木的外来入侵物种,而红带网纹蓟马寄主广泛,可吸食悬铃木叶片汁液,2个物种客观上发生了竞争关系。【方法】以悬铃木方翅网蝽与红带网纹蓟马共同发生的悬铃木种植街区为研究地点,每10d调查15根悬铃木枝条,记录各枝条各叶片上2个物种的数量,进而评价悬铃木方翅网蝽入侵对红带网纹蓟马的竞争排斥能力。【结果】悬铃木方翅网蝽在整个调查期间的种群数量明显高于红带网纹蓟马;悬铃木方翅网蝽在悬铃木上的时间生态位宽度和重叠指数均大于红带网纹蓟马,两者的时间生态位竞争系数达0.7022,明显高于对悬铃木枝条和叶片的竞争强度;悬铃木方翅网蝽和红带网纹蓟马对悬铃木枝条和叶片的竞争强度较低,且具有阶段性,空间竞争主要发生在6月中旬至7月下旬的2个种群发生高峰期;悬铃木方翅网蝽与红带网纹蓟马在悬铃木上的繁殖生态位出现了明显的时间分化,红带网纹蓟马仅秋季世代产卵于悬铃木叶片上,而悬铃木方翅网蝽所有世代均产卵于悬铃木叶上,但2个物种在悬铃木上共同繁殖期间,红带网纹蓟马选择产卵的枝条和叶片均有悬铃木方翅网蝽产卵,表明2个物种对产卵枝条和叶片具有相似的空间需求。【结论与意义】悬铃木方翅网蝽与红带网纹蓟马在悬铃木上整体的时空生态位竞争强度较弱,且2个物种的营养生态位差异较大;悬铃木方翅网蝽的入侵对红带网纹蓟马的生存和种群发展无明显影响。

Corythucha ciliata （Say） is a newly-identified invasive alien species mainly destroying Platanus spp. Selenothrips rubrocinctus （Giard） is another recent pest that targets these same widespread host plants. Observations of sap sucking events suggest that competition exists between S. rubrocinctus and C. ciliata. This study examined the competitive interactions of C. ciliate and S. rubrocinctus. [ Method] In this project, we recorded every 10 days the number of C. ciliata and S. rubrocinctus individu- als found on 15 marked branches Platanus spp. For the data, niche width and degree of overlap between species were calculated. [ Result] The population of C. ciliata was signficantly higher than that of S. rubrocinctus. The results showed that in general the niche width of C. ciliata was larger than the one of S. rubrocinctus. While the overlap between the temporal niches appeared small, the in- terspecific competition coefficient between the two species was 0.7022, suggesting high level of temporal competition between the two species. Spatial competition increased mainly in mid-June to late-July, compared to, significantly higher than the intensity of compe- tition on the branches and leaves of Platanus spp. ; The time differentiation of propagate niche with C. ciliate and S. rubrocinctus on the Platanus spp., only the autumn generation of S. rubrocinctus laid eggs on leaves of Platanus spp., but all generation of C. ciliata were laid eggs on leaves of Platanus spp., and common during the breeding on Platanus spp. by C. ciliate and S. rubrocinctus, the branches and leaves choiced by S. rubrocinctus for spawning were the same to C. ciliata, showed that two species of spawning bran- ches and leaves with similar space requirement. [ Conclusion and significance ] This study suggests that the invasion of C. ciliata may not have any negative effect on the survival and population dynamics of S. rubrocinctus.