Van Dam Alex R, Walton William E
Department of Entomology, University of California, Riverside 92521, USA.
J Am Mosq Control Assoc. 2007 Dec;23(4):430-41. doi: 10.2987/5620.1.
Two 6-wk trials were conducted in 28-m2 earthen ponds to compare the efficacy of the arroyo chub, Gila orcutti, to the mosquitofish, Gambusia affinis, as a biological control agent for mosquitoes and a possible replacement for the mosquitofish in sensitive watersheds of southern California. The mosquitofish population growth rate was 1.73 times greater than the arroyo chub population growth rate; however, greater reproduction by the mosquitofish did not result in significantly better reduction of mosquitoes than was provided by the comparatively small populations of arroyo chub. On average across a 6-wk study in the spring, both larvivorous fishes reduced the abundance of 3rd and 4th instars by 4- to 5-fold compared to that observed in the control ponds that lacked fish but contained few invertebrate predators. The abundance of nontarget microinvertebrates in ponds containing the mosquitofish was only 7% of that in ponds containing the arroyo chub during the summer, but did not differ significantly between the fish species treatments when zooplankton was comparatively more abundant during the spring. Even though the number of individuals produced by each fish species during 6 wk in the spring was greater than for fish stocked in the summer, species-specific population growth rates in the spring study (individuals/individual/d; mosquitofish, 0.077; arroyo chub, 0.044) were only slightly higher than in the summer (individuals/individual/d; mosquitofish, 0.068; arroyo chub, 0.039) indicating that differences in the number of fish stocked contributed primarily to the differences in final population size between spring and summer studies. The arroyo chub is native to the South Coastal drainages in California and should be considered as a viable alternative to the mosquitofish for integrated mosquito management programs in riverine wetlands and sensitive watersheds of southern California.
在28平方米的土池中进行了两项为期6周的试验，以比较科罗拉多钝口螈（Gila orcutti）与食蚊鱼（Gambusia affinis）作为蚊子生物防治剂的效果，以及在南加州敏感流域中食蚊鱼的可能替代物。食蚊鱼的种群增长率比科罗拉多钝口螈种群增长率高1.73倍；然而食蚊鱼繁殖量的增加并没有使其在减少蚊子数量方面比相对较少的科罗拉多钝口螈种群有显著更好的效果。在春季进行的一项为期6周的研究中，平均而言，与没有鱼类但有少量无脊椎动物捕食者的对照池塘相比，两种食蚊鱼类都使三龄和四龄幼虫数量减少了4至5倍。夏季，含有食蚊鱼的池塘中非目标微型无脊椎动物的数量仅为含有科罗拉多钝口螈池塘的7%，但在春季浮游动物相对较多时这两种鱼类处理之间没有显著差异。尽管春季6周内每种鱼类产生的个体数量比夏季放养的鱼类更多，但春季研究中的物种特异性种群增长率（个体数/个体/天；食蚊鱼，0.077；科罗拉多钝口螈，0.044）仅略高于夏季（个体数/个体/天；食蚊鱼0.068；科罗拉多钝口螈0.039），这表明放养鱼类数量的差异主要导致了春季和夏季研究最终种群规模的差异。科罗拉多钝口螈原产于加利福尼亚州南部沿海流域，并应被视为在南加州河流湿地和敏感流域的综合蚊虫管理计划中食蚊鱼的可行替代物。
