Vol. 1 1 1 , No. 1 , January & February, 2000 1 3 MONOMORIUM MINIMUM SPECIES GROUP: GYNE NUMBER AND LONGEVITY (HYMENOPTERA: FORMICIDAE) 1 Mark B. DuBois 2 ' 3 > 4 ABSTRACT: Gyne number is reported for 13 species of the Monomorium minimum species group; life span, and worker mortality rates are presented for 5 species: Monomorium cyaneum, M. emarginatum, M. minimum, M. trageri, and M. viride. Most species appear able to establish colonies haplometrotically; most exhibit presumed secondary polygyny. Average gyne lifespans (under laboratory conditions) ranged from 1 .08 years (M. minimum) to 7.54 years (M. emarginatum). Worker longevity for M. cyaneum ranged up to 1.4 years. The ant genus Monomorium is represented by over 350 species (Bolton, 1995). There is no information concerning basic biology (such as number of gynes per colony and life span of gynes and workers) of most species. Keller (1998) conducted an extensive literature review and incorporated unpub-lished information regarding ant gyne life spans and related factors. Of the 53 ant species he discussed, only one species (Monomorium pharaonis (Linnaeus)) was included (Peacock and Baxter, 1950; Peacock et al., 1955). Keller's work expanded on the known life spans of 31 ant species' provided by Holldobler and Wilson (1990: 169). Bolton (1995) listed over 9,500 spe-cies of ants. The purpose of Keller's research was, "to test evolutionary theories on aging by investigating whether the evolution of eusociality had been paral-leled by an increase in queen life span..." This is the expected pattern if life span is influenced by extrinsic mortality factors (Keller, 1998: 236). A side result was the confirmation of the paucity of knowledge of this aspect of basic ant biology. Comparative theories are difficult to evaluate when there are limited observations within a large and diverse group. This publication provides longevity data for Monomorium cyaneum Wheeler, M. emarginatum DuBois, M. minimum (Buckley), M. trageri DuBois, and M. viride Brown. These are the first recorded observations for multiple members of the minimum species group (DuBois, 1986) for colonies kept under similar laboratory conditions. Although colonies were collected at different times, all were subjected to a similar regimen in the laboratory. 1 Received March 1, 1999. Accepted April 10, 1999. 2 116 Burton Street, Washington, IL 61571-2509. 3 Research Affiliate, Center for Biodiversity, Illinois Natural History Survey, 607 East Peabody Drive, Champaign, IL 61820. 4 Send reprint requests to the Washington, Illinois address. ENT. NEWS 111(1), 13-20, January & February, 2000
BioStor
