Preliminary observations on the impact of Aculus mosoniensis, perspective biological control agent of Ailanthus altissima

Ailanthus altissima, tree of heaven is an introduced tree species in Europe, Africa, South America and North America. Seeds were introduced from China to France in the middle of 1700s and in North America as an ornamental shade tree during the late 18th century from Europe. It is a serious threat to ecosystems in introduced areas, as the plant is very competitive through allelopathic chemicals that may inhibit growth of surrounding native plants. It has a complex of secondary chemicals that make it unpalatable to most of the phytophagous generalist arthropods. Management of this species has been very difficult because of its fast growth and production of root-suckers. Europe uses the classic approach using mechanical and chemical treatments which provide only short-term control, however, this usually exacerbates the problem. One potential agent for Ailanthus, the eriophyid mite Aculops mosoniensis (Acari: Eriophyoidea), has been already recorded in six European States: Hungary, Italy, Serbia, Austria, Croatia, Macedonia and Greece. Beside to the classic symptoms associated with the mite infestation (leaf rolling), an important impact has been recorded on the growth and the survival rate of young plants. In this work we are providing some life history data and we are describing the results of some impact bioassays carried out in field and laboratory conditions, comparing the effects of classic biological control alone and in combination with other management approaches.