|Budget Amount *help
¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1992 : ¥300,000 (Direct Cost : ¥300,000)
Fiscal Year 1991 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1990 : ¥1,000,000 (Direct Cost : ¥1,000,000)
To clarify the fecundity of queens and workers of each species, the number of ovarioles and egg size were surveyed. Number of ovarioles on 62 spp. clarified the degree of queen control on worker oviposition through ovaries. Ants are divided into 3 groups; a) workers have the same number of ovarioles with queen, which are restricted to subfamily Ponerinae, b) worker' s ovarioles are reduced to 1, which are common to 4 subfamilies studied, c)workers have no ovary, such are restricted to some taxon of subfamilies Ponerinae and Myrmicinae. Egg size in comparison with queen body size were correlated with ovariole numbers and divided into 3 groups; large, medium and small egg species.
Surveys on the Malpighian tubule numbers conducted with those of the ovariole numbers showed that Myrmicinae have conspicuous, having low tubule numbers irrespective to the ovariole numbers and body size.
Laboratory observations on the oviposition and the fate of eggs in the colony showed that oophagy of the viable eggs were common in many species. Even in primitive Ponerine species which have small number of ovarioles, eggs were important food source for 1st instar larvae. In other case, worker eggs were consumed by the queen(gamergate) preventing the male production. Trophic egg layings were restricted to the species which have higher number of ovarioles and the queen control herself by laying 2 types of eggs.