Specialized pollinators and seed production of Trollius species introduced in Western Siberia

Abstract

In five species of Trollius L., seed production of fruits was studied, plants being grown in culture in the forest steppe zone in Western Siberia. 2 species representing Chiastocheta genus were identified as specialized pollinators (Diptera, Anthomyiidae). Those insects pollinate the flowers and damage the seeds of three globeflower species: T. apertus, T. europaeus T. asiaticus. The flower season of other two species (T. chinensis and T. ledebourii) starts later and the plants can’t be exposed to invasion, as Chiastocheta flies are at their larval stage yet. Pollination of these species is performed by non-specialized agents. The lowest rate of seed production realization of about 20% is registered in T. europaeus, while in T. ledebourii it is the highest comprising 71%. We consider the flies of Chiastocheta genus as an important part of the complex of factors lowering seed productivity in Trollius and their relationship as parasitism. Thus, in West Siberia for Trollius seed production increase, measures intended to reduce Chiastocheta abundance will be useful.