Dual mimicry in the dimorphic eusocial waspMischocyttarus mastigophorusRichards (Hymenoptera: Vespidae)

Abstract

The eusocial vespid waspMischocyttarus mastigophorusexhibits two colour morphs, with males and females of each morph co-occurring at Monteverde, Costa Rica. Each morph closely resembles a different sympatric species of swarm-founding wasp in the genusAgelaia. We propose that theAgelaiaspecies are models for a dual mimicry system. TheAgelaiaspecies (A.yepocapa, mimicked by theM. mastigophoruspale morph, andA. xanthopus, mimicked by theM. mastigophorusdark morph) are locally abundant wasps with large, aggressively defended colonies. The mimic and models are restricted to high-elevation habitat in the Monteverde area, and the elevational ranges of bothAgelaiaspecies partially overlap the elevational range ofM. mastigophorus. Relative frequencies of theM. mastigophoruscolour morphs vary with elevation, with the pale morph predominating at lower elevations. Elevational differences in the relative abundances of theAgelaiaspecies suggest that the models act as a selective force maintaining theM. mastigophoruscolour polymorphism at Monteverde.Mischocyttarus mastigophorusoverlaps onlyA. xanthopusin the northern part of its range (S. Mexico), and overlaps onlyA. yepocapain the southern part of its range (Ecuador). We hypothesize that theM. mastigophoruscolour morphs evolved in allopatry and later came into contact in Central America. Appropriate high-elevation habitat for cloud forest species is distributed as discrete patches in Central America and Northern South America. The island-like nature of suitable habitat may favour the isolation and rapid evolutionary diversification of vespid species that are restricted to high elevations in the Neotropics.