Study on behavioural ecology of Ditomus calydonius Rossi, 1790 (Coleoptera: Carabidae: Ditomina), a strictly granivorous ground beetle with brood care

The ecology of Ditomus calydonius is investigated mainly in the field, to define the poorly known habitat choice, the seasonal and reproduction rhythm, the circadian activity rhythm, the relationships with the food plant, Daucus spp. and the nesting behav-iour. After pitfall-trapping of 120 sites in Calabria, the preferred habitat is found in open land on clayey soil, where this species lives stenotopic especially on south-ern-aspect slopes. The population activity is remarkable for its late onset in the year (June), strictly nocturnal daily rhythm, possible intrahabitat micromigration from early flourishing Daucus plants to later ripening patch-es. Short data concerning foraging/feeding behaviour, shape of the only one nest found in nature and ability and time of flight are presented. Some data concerning laboratory behaviour and nesting have been added. Territorial combatative interaction between males, hith-erto rarely observed in Carabidae, has discovered in this species for the first time.