Leafhoppers and cixiids in phytoplasma-infected carrot fields: Species composition and potential phytoplasma vectors

Abstract

The first molecular analysis of samples collected in southern Backa (Serbia) confirmed the presence of aster yellows (16SrI) and stolbur phytoplasmas (16SrXII) in insects belonging to the family Cicadellidae, as well as in carrot plants where the insects were collected. A correct identification of the phytoplasmas and their vectors is essential to arrange effective control strategies to prevent diseases associated with phytoplasmas from spreading to carrots and other vegetable crops. In order to enhance knowledge about insect vectors of aster yellows and stolbur phytoplasmas in Serbia, Cicadellidae and Cixiidae (Homoptera Auchenorrhyncha), the most common vectors of these phytoplasmas, were monitored in southern Backa during 2008. Adults leaf- and planthoppers were collected and identified at species level using standard entomological methods, and tested for phytoplasma presence by means of PCR/RFLP. A total of 13 insect species of Cicadellidae were identified, as follows: a) three species of the subfamily Agallinae: Anaceratagallia ribauti (Ossiannilsson), Anaceratagallia venosa (Fourcroy), and Anaceratagallia laevis (Ribaut); b) seven species of the subfamily Deltocephalinae: Psammotettix confinis (Dahlbom), Psammotettix striatus (Linnaues) Psammottettix alienus (Dahlbom), Macrosteles sexnotatus (Fall?n), Ophiola decumana (Kontkanen), Errastunus ocellaris Fall?n, and Scaphoideus titanus Ball; c) three species of the subfamily Typhlocibinae: Eupteryx atropunctata (Goeze), Eupteryx mellissae Curtis, Zyginidia pullula (Boheman). Female specimens of the genus Euscelis (Deltocephalinae) were also collected, as well as one species of Reptalus quinquecostatus (Dufour) of the family Cixiidae. Stolbur phytoplasmas were detected in A. laevis, A. ribauti, A. venosa, P. striatus, P. confinis and P. alienus. The species: A. laevis, O. decumana, and P. confinis were AY-infected (subgroup 16SrI-A), while subgroup 16SrI-C was found only in one specimen of P. confinis. Since some aster yellows- and stolbur-infected species of the genera Psammotettix and Anaceratagallia (especially P. confinis and A. laevis) were regularly and commonly found in the infected carrot fields during the whole vegetative period, they could play a significant role in transmitting and spreading these pathogens in natural environment.