Investigating the Subspecific Designation of Euschistus servus (Say) (Hemiptera: Heteroptera: Pentatomidae) Using a Combined Landmark-Based Geometric Morphometrics Approach
Abstract
Euschistus servus is currently subdivided into two subspecies: E. s. servus and E. s. euschistoides. An intergrade population inhabits the central U.S. This study sought to reevaluate the established subspecific designations and determine whether E. servus subspecies and intergrade populations express distinct taxonomically important morphological characteristics throughout the U.S. We quantified landmark-based geometric morphometric data in conjunction with traditional morphometrics from specimens collected along a wide geographic area and used a principal component analysis to determine if there is a significant difference within the subspecies’ morphology, assessing shape between morphogroups failed to produce clusters commensurate to the E. s. servus and E. s. euschistoides forms. Further analysis suggested that there is linear relationship between the taxonomic characters and latitude which may be indicative of clinal variation. This data indicates E. servus should be recognized as polymorphic as opposed to polytypic, disputing the subspecific designation of the E. servus subspecies complex.