Castes in the neotropical social wasp Leipomeles dorsata (Fabricius) (Hymenoptera: Vespidae): a window for workers achieving a new status in the colony

Abstract

-Morphometric studies performed in several species of Neotropical social wasps from the tribe Epiponini showed that in some species there are marked differences between castes, while other species present highly distinct castes with differences only in ovarian development. This work analyzed females from six colonies of the social wasp Leipomeles dorsata (Fabricius) in which queens (egglayers) and workers showed differences in ovarian development and coloration. We propose that wasps with developed ovaries (egglayers) and coloration similar to those of workers are possibly intermediates that obtained the status of queens in the colony.

An adaptive view of caste differentiation in the neotropical wasp Polybia (Trichothorax) sericea Olivier (Hymenoptera: Vespidae)

“…The literature regarding caste in the Epiponini establishes two main strategies for caste determination: (1) pre-imaginal, in which queens form morphological clusters distinct from workers and (2) post-imaginal caste differentiation where castes are more flexible and non-reproductive resemble reproductive adults (Noll et al 2010). Our data clearly indicate that caste determination in P. (T.) sericea is pre-imaginal.…”

“…The strategy adopted by the studied species, as well by other Epiponini, ensures that workers may have a lower chance to achieve a reproductive status than in species in which caste differences are only slight or absent. In fact, Noll et al (2010) proved that in species with slight caste differentiation, such as Leipomeles dorsata (Fabricius), workers may become reproductively active. Finally, the pattern of caste differentiation showed in this study seems to operate in other lineages of Epiponini as well, such as Agelaia, Apoica and other Polybia (Pizzarro et al 2009).…”

“…According to Noll et al (2004), four different syndromes are now recognized in the Epiponini: (1) casteless -no morphological differences in size or shape and the presence of females with all ovary developmental conditions (Shima et al 1998, Mateus et al 2004, (2) without a clear morphological distinction, but physiological differences with the presence of intermediate females (Noda et al 2003, 2010, (3) queens larger than workers, but no shape differences , and (4) caste differences based on shape, with queens smaller than workers in some variables and larger in others (Shima et al 1994, 1996a,b, 2003, Hunt et al 1996, Desuó et al 2011.…”