SOCIOGENETIC ORGANIZATION OF THE ANTS MYRMICA-RUGINODIS AND MYRMICA-LOBICORNIS - NUMBER, RELATEDNESS AND LONGEVITY OF REPRODUCING INDIVIDUALS

The number and relationships of reproducing individuals create the obs erved genetic heterogeneity within a social insect colony. These are r eferred to as sociogenetic organization and were studied in the red an ts M. ruginodis and M. lobicornis. Direct observations of the queen nu mbers were obtained by excavating colonies. The effective number of re producing individuals was estimated from genetic relatedness based on genotype frequency data. Sociogenetic organization of colonies of both species is simple. The number of queens is low, single mating of quee ns is the rule and queen to queen variation in worker production is mi nor. The important variables of sociogenetic organization are the numb er and relatedness of coexisting queens in polygynous colonies. Queen nestmates are related on average by 0.405 in polygynous colonies of M. ruginodis, showing that colonies recruit their own daughters as new r eproductives. The distribution of queen number in M. ruginodis indicat es that the study population contains both microgyna and macrogyna typ es of the species. The large proportion of colonies where the resident queen(s) is not the mother of the workers shows that the average life span of a queen is short and colonies are serially polygynous.