No abstract

Foundress associations and high frequencies of conspecific nest usurpation are most common where densities of Polistes metricus are high. Here nest usurpation occurs primarily in single-foundress colonies resulting in multiple-foundress colonies having significantly greater productivities than single-foundress colonies. This is not true at low densities. Conspecific pressures and not predation or parasitism provide an advantage to cooperating wasp foundresses in P. metricus.

Polistes dominulus (Christ), an old world paper wasp, was introduced accidentally into the eastern coast of the United States in the late 1970s and has been rapidly spreading westward, displacing the native P. fuscatus (F.). The biology of naturally nesting P. fuscatus and P. dominulus was compared at a field site in Rochester, Michigan. The basic methodology consisted of simultaneously videotaping spatially proximate, matched single-foundress colonies of P. fuscatus and P. dominulus (13 matched sets, 176.8 h of videography). In addition, extensive surveys and censuses were taken of colonies to record colony productivity, dates of nest initiation and first worker emergence, usurpation and parasitism.There was no evidence that P. dominulus is negatively impacting P. fuscatus through direct, agonistic encounters. However, P. dominulus is 4-5 times more productive than P. fuscatus, suggesting that P. dominulus is replacing P. fuscatus via exploitative competition. P. dominulus appears to have a number of advantages over P. fuscatus, including earlier production of workers, higher per capita foraging rates by queens and workers, higher queen survivorship, and lack of conspecific pressures. Nest site and/or prey availability may be limiting factors in the competition between the two species.

The biology of the invasive Polistes dominulus and the native P. fuscatus was compared at a field site in Rochester, Michigan over a two-year period. Colonies nesting semi-naturally in plywood nestboxes were studied using videography, extensive surveys, and colony-specific marking of gynes.Both single-and multiple-foundress colonies of P. dominulus were significantly more productive than comparable colonies of P. fuscatus. The disparity in productivity was significantly more pronounced in single-foundress colonies than in multiple-foundress colonies. P. dominulus had significantly shorter larval and pupal development times than P. fuscatus, which allowed P. dominulus to produce its first workers about a week earlier than P. fuscatus. P. dominulus had a number of additional advantages over P. fuscatus that contributed to its productivity including (1) significantly less parasitism by Strepsiptera, (2) significantly greater probability of renesting after predation by raccoons, (3) significantly lower usurpation pressures, and (4) possibly longer foraging days . The recovery of colony-marked foundresses indicated that gynes of P. dominulus suffered significantly greater mortality than gynes of P. fuscatus during winter diapause and that foundresses of both species were equally, strongly philopatric.P. dominulus is likely replacing P. fuscatus in many areas of southeastern Michigan via indirect or exploitative competition. The two species may be competing for nest sites.

During the past decade, a substantial and rapidly expanding literature has documented that a diversity of hymenopterans have the ability to recognize their conspecific nestmates (22). As recognition research enters its second generation, investigators are turning their attention to elucidating the mechanisms of nestmate recognition and how the features of these mechanisms, as well as recognition ability itself, relate to an animal's sociobiology. Such studies are important not only because of their relevance to an understanding of the evolution and ecology of hymenopteran sociality, but also because of their potential application for control of economically important social insects.In our review, we summarize the evidence for nestmate recognition ability in social wasps, and examine in detail the mechanism of female-female nestmate recognition using primitively eusocial wasps (Polistes) as a model. We also compare the Polistes mechanism with mechanisms proposed for other social Hymenoptera and ,with the major theoretical models of kin recognition developed for animals in general. This is followed by a discussion of the possible adaptiveness of both female-female nestmate recognition ability and the specific mechanisms underlying this ability. Finally, we explore the preadaptations 431