DEFINITION OF WING FORM AND MORPHOMETRIC TRAITS OF THE ADULT STINK BUG, PYRRHOCORIS-SIBIRICUS (HETEROPTERA, PYRRHOCORIDAE)

The stink bug, Pyrrhocoris sibiricus, which is a ground-living seedfee der, shows wing polymorphism. To define the wing form and investigate the relationship between body size and wing polymorphism, adults colle cted from natural habitats were measured for their body length and for ewing and hindwing lengths. The coloration of the hindwing (blackish o r semitransparent) and the distinctness of the hindwing venation (dist inct or indistinct) were also checked for all individuals. Individuals with blackish hindwings had distinct (developed) wing venation and sh owed larger values of relative hindwing length (RHL), while those with semitransparent hindwings had indistinct (undeveloped) wing venation and showed smaller RHL values. Moreover, the RHL values of individuals with different colors did not overlap. In female adults, individuals with an RHL equal to or greater than 0.4 were defined as macropters an d those with an RHL of less than 0.4 were defined as brachypters. In m ale adults, individuals with an RHL equal to or greater than 0.5 were defined as macropters and those with an RHL of less than 0.5 were defi ned as brachypters. Macropters had larger body sizes than brachypters in both sexes.