Role of Tropical Greenhouses For Introduction and Establishment of Foreign Ant Species (Hymenoptera: Formicidae) in Central Europe

Abstract:
Introduction of exotic ants to Central Europe plays an increasing role for the last twenty years caused by the growing world trade and short transportation routes. Particularly tropical greenhouses offer ideal conditions for ant species with high temperature and humidity preferences and with ability to withstand cold and dry conditions during transportation. The colonies are found in the soil, in rotten wood and leaves but also well hidden in cavities of plant bulbs. Thirteen foreign and five European ant species belonging to the subfamilies Formicinae, Dolichoderinae, Myrmicinae and Ponerinae were identified from samples which were sent from 24 botanical and zoological gardens. Most of these ant species feed on sweet nutrition and tend aphids which may be defended against predators/parasitoids and distributed over the cultivated area. White footed ants (Technomyrmex vitiensis) were found in many green house localities, often in high populations. Plagiolepis sp. is also common in many greenhouses with tropical climate. A few species are of medical importance like species of the genus Cardiocondyla which live in small colonies in the foliage. Two Cardiocondyla species were found in separate greenhouses. The workers may sting people severely, when they are pruning the plants. Instructions for control of these species are presented with regard to the special circumstances in greenhouses with a sensitive flora and the use of beneficial insects.