Department of Entomology, University of Nebraska , Lincoln, NE , USA.
Department of Biology, Chadron State College , Chadron, NE , USA.
PeerJ. 2014 Jun 10;2:e418. doi: 10.7717/peerj.418. eCollection 2014.
The sagebrush grasshopper, Melanoplus bowditchi Scudder (Orthoptera: Acrididae), is a phytophilous species that is widely distributed in the western United States on sagebrush species. The geographical distribution of M. bowditchi is very similar to the range of its host plants and its feeding association varies in relation to sagebrush distribution. Melanoplus bowditchi bowditchi Scudder and M. bowditchi canus Hebard were described based on their feeding association with different sagebrush species, sand sagebrush and silver sagebrush, respectively. Recently, M. bowditchi have been observed feeding on other plant species in western Nebraska. We collected adult M. bowditchi feeding on four plant species, sand sagebrush, Artemisia filifolia, big sagebrush, A. tridentata, fringed sagebrush, A. frigidus, and winterfat, Krascheninnikovia lanata. We compared the specimens collected from the four plant species for their morphological and genetic differences. We observed no consistent differences among the aedeagal parameres or basal rings among the grasshoppers collected from different host plants. Amplified Fragment Length Polymorphism markers were used to test the genetic relationships among the grasshoppers. Analysis of Molecular Variance and distance-based Unweighted Pair Group Method with Arithmetic mean dendrogram failed to reveal significant differences. Although the forms showed behavioral and minor color and size differences, the genetic data suggest all forms under study likely interbreed, which indicates they are a single species instead of four species or subspecies. These results indicate that host plant use may influence melanopline phenotype and suggest the need of further genetic analysis of subspecies recognized based on morphology, distribution, and ecology.
刺足拟蝗，Melanoplus bowditchi Scudder（直翅目：蝗科），是一种喜草的物种，广泛分布于美国西部的各种蒿属植物上。M. bowditchi 的地理分布与它的宿主植物非常相似，其取食关系随蒿属植物的分布而变化。M. bowditchi bowditchi Scudder 和 M. bowditchi canus Hebard 是根据它们与不同的蒿属植物（沙蒿和银蒿）的取食关系而被描述的。最近，在内布拉斯加州西部观察到 M. bowditchi 取食其他植物物种。我们收集了取食四种植物的成年 M. bowditchi，分别是沙蒿、黄花蒿、大针茅、三齿青蒿、多枝薊和冬白。我们比较了从这四种植物上采集的标本在形态和遗传上的差异。我们没有观察到从不同宿主植物上采集的蝗蝻的触角前翅突或基环有一致的差异。扩增片段长度多态性标记被用来检测蝗蝻之间的遗传关系。分子方差分析和基于距离的非加权对组平均聚类树状图分析都没有揭示出显著的差异。尽管这些形态表现出行为和微小的颜色和大小差异，但遗传数据表明，研究中的所有形态可能会杂交，这表明它们是一个单一的物种，而不是四个物种或亚种。这些结果表明，宿主植物的利用可能会影响拟蝗的表型，并表明需要进一步进行基于形态、分布和生态的亚种遗传分析。
