title: Quantitative differences in nourishment affect caste-related physiology and development in the paper wasp Polistes metricus.
abstract: The distinction between worker and reproductive castes of social insects is receiving increased attention from a developmental rather than adaptive perspective. In the wasp genus Polistes, colonies are founded by one or more females, and the female offspring that emerge in that colony are either non-reproducing workers or future reproductives of the following generation (gynes). A growing number of studies now indicate that workers emerge with activated reproductive physiology, whereas the future reproductive gynes do not. Low nourishment levels for larvae during the worker-rearing phase of the colony cycle and higher nourishment levels for larvae when gynes are reared are now strongly suspected of playing a major role in this difference. Here, we present the results of a laboratory rearing experiment in which Polistes metricus single foundresses were held in environmental conditions with a higher level of control than in any previously published study, and the amount of protein nourishment made available to feed larvae was the only input variable. Three experimental feeding treatments were tested: restricted, unrestricted, and hand-supplemented. Analysis of multiple response variables shows that wasps reared on restricted protein nourishment, which would be the case for wasps reared in field conditions that subsequently become workers, tend toward trait values that characterize active reproductive physiology. Wasps reared on unrestricted and hand-supplemented protein, which replicates higher feeding levels for larvae in field conditions that subsequently become gynes, tend toward trait values that characterize inactive reproductive physiology. Although the experiment was not designed to test for worker behavior per se, our results further implicate activated reproductive physiology as a developmental response to low larval nourishment as a fundamental aspect of worker behavior in Polistes.
authors.affiliation: Department of Biology, Southeast Missouri State University, Gape Girardeau, MO, 63701, United States of America.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Judd
authors.affiliation: Center for Medical, Agricultural and Veterinary Entomology, USDA-ARS, 1700 SW 23 Drive, Gainesville, FL, 32604, United States of America.
authors.forename: Peter E A
authors.initials: PE
authors.lastname: Teal
authors.affiliation: Department of Biology, University of Missouri Saint Louis, Saint Louis, MO, 63121, United States of America.
authors.forename: Edgar Javier
authors.initials: EJ
authors.lastname: Hernandez
authors.affiliation: Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, United States of America.
authors.forename: Talbia
authors.initials: T
authors.lastname: Choudhury
authors.affiliation: Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, United States of America; Department of Entomology, W. M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC, 27695, United States of America.
authors.forename: James H
authors.initials: JH
authors.lastname: Hunt
mesh_terms: D000818:Animals; D005260:Female; D007814:Larva / Q000502:physiology; D009752:Nutritional Status; D010053:Ovary / Q000254:growth & development*; D010641:Phenotype; D012098:Reproduction / Q000502:physiology*; D014863:Wasps / Q000254:growth & development / Q000502:physiology*