Social evolution in South American polistine wasps

1999 Fiscal Year Final Research Report Summary

• Project/Area Number: 10041154
• Research Category: Grant-in-Aid for Scientific Research (B).
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 生態
• Research Institution: IBARAKI UNIVERSITY
• Principal Investigator: YAMANE Soichi Ibaraki university, Faculty of Education, Professor, 教育学部, 教授 (40091871)
• Co-Investigator(Kenkyū-buntansha): TSUCHIDA Koji Gifu University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (00252122) ; ITO Yosiaki Professor Emeritus, Nagoya University, 名誉教授
• Project Period (FY): 1998 – 1999
• Keywords: Social wasp / Polistinae / South America / Swarm founding / Multiple queen social system / Genetic relatedness / DNA / Caste differentiation

Research Abstract

The followings were studied during 1998 and 1999.
(1) "Estimation of genetic relatedness among colony members" To analyze the social system from genetic relatedness among colony members, Polybia paulista was chosen and 15 colonies at various developmental stages were collected in and around Ribeirao Preto. Since there was a possibility that multiple queens were really functioning by occupying their own territories at different combs, immatures were taken from each comb separately as well as adult wasps. To apply a DNA micro-satellite method, effective primer sets are being prepared by Tsuchida and co-workers.
(2) "Morphological caste differentiation" The developmental degree of social system may be reflected to morphological differences between queens and workers. We have compared such differences among various social wasps, especially Polistinae that have remarkably diverged in the South American Continent. To add more data, Yamane and co-workers analyzed two Polybia species, P. occiden talis and P. paulista, by a multi-variate analysis with which the inter-caste distances can be estimated. The result for P. occidentalis has been submitted to "Entomological Science".
(3) "Composition of chemical components in the material of polistine nests" Social wasp nests have a function for rearing immature stages. To clarify their architecture and construction technology, Kudo (cooperative researcher) and Yamane have analyzed the chemical components of Polybia paulista nests. The oral secretion, secreted by wasps to glue extraneous materials, of P. paulista contained 24 amino acids, among which Proline (structural amino acid), Serine, Glycine and Alanine were predominant (>10% in quantity). Such characteristics were compared with other species for discussing its biological and phylogenetic significances.
(4) "Theoretical consideration of the evolution of multi-queen social system in the Polistinae" Based on the present results and so far published work, Ito has developed a comprehensive model for explaining the evolution of multi-queen social system in the Polistinae. A preliminary note for this problem is presented.