Data from: Discrimination of grasshopper (Orthoptera: Acrididae) diet and niche overlap using next-generation sequencing of gut contents

Species of grasshopper have been divided into three diet classifications based on mandible morphology: forbivorous (specialist on forbs), graminivorous (specialist on grasses), and mixed feeding (broad-scale generalists). For example, Melanoplus bivittatus and Dissosteira carolina are presumed to be broad-scale generalists, Chortophaga viridifasciata is a specialist on grasses, and Melanoplus femurrubrum is a specialist on forbs. These classifications, however, have not been verified in the wild. Multiple specimens of these four species were collected, and diet analysis was performed using DNA metabarcoding of the gut contents. The rbcLa gene region was amplified and sequenced using Illumina MiSeq sequencing. Levins' measure and the Shannon–Wiener measure of niche breadth were calculated using family-level identifications and Morisita's measure of niche overlap was calculated using operational taxonomic units (OTUs). Gut contents confirm both D. carolina and M. bivittatus as generalists and C. viridifasciata as a specialist on grasses. For M. femurrubrum, a high niche breadth was observed and species of grasses were identified in the gut as well as forbs. Niche overlap values did not follow predicted patterns, however, the low values suggest low competition between these species.

蝗虫物种可依据颚形态被划分为三类食性类别：专食阔叶草本类（forbivorous，即专以非禾本科草本植物为食）、专食禾本科草本类（graminivorous，即专以禾本科草本植物为食）以及混合食性泛化类群。例如，双带黑蝗（Melanoplus bivittatus）与卡罗琳蝗（Dissosteira carolina）被推测为广食性泛化类群，绿条蝗（Chortophaga viridifasciata）为禾本科草本专食者，红腿蝗（Melanoplus femurrubrum）则为阔叶草本专食者。然而，上述食性分类尚未在野外环境中得到验证。本研究采集了该四个物种的多份标本，通过对肠道内容物进行DNA元条形码（DNA metabarcoding）分析开展食性鉴定。利用Illumina MiSeq测序平台对rbcLa基因区域进行扩增与测序。基于科级分类单元的鉴定结果，计算了Levins生态位宽度指数与Shannon-Wiener生态位宽度指数；基于操作分类单元（operational taxonomic units, OTUs），计算了Morisita生态位重叠指数。肠道内容物分析证实，卡罗琳蝗与双带黑蝗确为广食性类群，绿条蝗为禾本科草本专食者。对于红腿蝗，观测到较高的生态位宽度，其肠道内不仅检出阔叶草本类群，同时也检测到禾本科草本类群。生态位重叠值未呈现预期的分布模式，但其较低的数值表明这些蝗虫物种间存在较低的种间竞争水平。