IS IT POSSIBLE TO DISTINGUISH ALIEN SPECIES OF BEETLES (COLEOPTERA) FROM NATIVE ONES?
Species established outside their native range are termed alien. Biological invasions of beetles are poorly studied. Distinguishing between alien and native species is necessary for conservation as well as for taxonomic, zoogeographic and evolutionary studies. It constitutes a difficult problem, but the experience of botany and some branches of zoology gives reasons to believe that it is not insoluble. The following criteria for distinguishing alien beetle species from native ones are proposed based on criteria developed for plants, algae, mammals and marine invertebrates: 1) detection of established population of species, which has not been recorded before in the region; 2) disjunction of the range which cannot be explained by disjunction of suitable landscapes or ranges of host plants; 3) expansion of a part of the range distant from the main part of the range; 4) highly localized distribution in an area adjacent to recognized pathway; 5) establishment in other regions; 6) dependency on a non-native species (feeding on alien host plant or animal); 7) absence of specific parasites in this region and their presence in some other region; 8) association with anthropogenic biotopes; 9) sharp fluctuation of abundance; 10) lack of taxonomically close species in this region and their presence in another region; 11) detection in the region of two or more taxonomically and/or ecologically close species typical of another region; 12) presence of recognized vectors of invasion; 13) low genetic diversity; 14) reproduction by parthenogenesis or inbreeding. These criteria are indirect evidences of alien status of a species in certain territory, because numerous exceptions exist. Usually it is impossible to recognize an alien species by one criterion, but fitting several criteria with high probability points at the species as an alien one.