Neotropical Social Wasps Research Articles

Relatedness and queen number in the Neotropical wasp, Parachartergus colobopterus

The maintenance of sociality is most difficult to explain under circumstances where non-reproducing helpers are physiologically capable of reproducing and distantly related to the brood they rear. The Neotropical swarm-founding wasps are likely to fulfil these conditions because most taxa lack morphological differences between workers and queens, and they have many queens per nest, which is expected to substantially lower worker to brood relatedness. No morphological differences between workers and queens in Parachartergus colobopterus were detected. Colonies contained an average of 27 queens. However, relatedness among nestmates in P. colobopterus was higher ( r=0·31) than would be expected on the basis of queen number alone because the queens themselves are very closely related ( r=0·67) and because of large variation in numbers of queens among colonies. This makes the harmonic mean of queen number (five queens), which is the appropriate measure for investigating the impact of queen number on relatedness, much lower than the arithmetic mean. Reproductive dominance of one or a few queens within colonies was not a factor that greatly increased relatedness among workers. Taken together, these results support the cyclical oligogyny hypothesis for the maintenance of sociality in Neotropical social wasps.

Chemical defense of brood by a social wasp.

Ants are a constant threat to the nests of tropical social wasps. Adults of the neotropical social wasp Mischocyttarus drewseni apply a secretion to the nest stem which is repellent to ants foraging for food by scouting and recruiting, and effectively keeps them from gaining access to the nest and discovering the brood.

On the So-Called Mischocyttarus Ater, Polybia Atra, and Their Relatives (Hymenoptera, Vespidae)

Several closely related species of neotropical social wasps are homeochromic with the so-called Polybia atra de Saussure. Their differentiation is as yet far from clear and will be discussed in this paper. First, however, the involved nomenclature of P. atra and its homonym, Mischocyttarus ater, should be cleared up. The prevailing tangle is due mainly to a series of errors and subsequent corrections made by de Saussure in his Monograph of Social Wasps. As I believe current use of these names incorrect, all pertinent evidence is given in full and in chronological order. The years refer to the bibliographies in the taxonomic discussions of the several species.