English: Trechus apicalis Motschulsky. This trechine species is “wing dimorphic” with the vast majority of individuals being micropterous (with short wing vestiges) and a few macropterous (with long wings). Usually macropterous individuals of dimorphic species are able to fly but this is not always the case as flight muscles could be atrophied. Carl Lindroth argued that in stable periods, when the species’ habitat is not subject to drastic changes, the brachypterous form normally predominates but in unstable periods, the situation is reversed.