A review of the European species of the genus Trechnites Thomson (Hymenoptera: Chalcidoidea: Encyrtidae), parasitoids of plant lice (Hemiptera: Psylloidea) with description of a new species

The genus Trechnites Thomson (Hymenoptera: Encyrtidae) includes species that have the potential to be used as biocontrol agents of psyllid pests. The five species known from Europe are reviewed, including the newly described T. sadkai sp.n. A dichotomous key is provided to facilitate the identification of females; T. psyllae (Ruschka) syn. n. is proposed as a new synonym of T. insidiosus (Crawford). Each species is further characterized by a diagnosis or a redescription, and figures and notes are provided on their known distribution and hosts. © 2009 The Royal Entomological Society.