Gonçalves Zanfelici Luiz Fernando

Surveying the Dysaphis devecta species-complex in Europe

Magyar Agrár- és Élettudományi Egyetem

Kertészettudományi Doktori Iskola

Markó Viktor

Benyóné György Zsuzsanna

társ

PhD

Dysaphis devecta Walker is a common and widely studied pest of apple in Europe. It is autoecious on apple, and causes the leaves of its host plant to curl and become characteristically red. Much less is known about the other heteroecious twin-species of D. devecta. Three species of the D. devecta species-complex [D. anthrisci Börner, D. chaerophylli (Börner) and D. radicola Mordvilko] are mentioned to occur in apple orchards in western and central Europe. However, the D. devecta species-complex comprises at least eight species and several subspecies from which five (D. anthrisci Börner, D. caerophylli Börner, D. devecta Walker, D. flava Shaposhnikov, D. radicola Mordvilko) is presumably present in Central Europe. All the species of the complex use apple as primary host. Identification of these species based on morphological characters is very difficult or even impossible, and the separation can be obtained by a detailed and very laborious morphometrical analysis. Individuals belonging to different species of the complex can be collected on their different secondary host plants. With the development of molecular techniques in recent years a number of corresponding species-complexes has been divided into separate species and subspecies through their COI-DNA barcodes, in several cases secondary host-plant specific cryptic species were also found. However, the D. devecta species-complex has not been studied using molecular techniques and their abundance and distribution in apple orchards is not known. The PhD candidate will investigate the phylogenetic relationship of the Central European members of D. devecta species complex (D. anthrisci, D. careophylli, D. devecta, D. flava and D. radicola) through molecular analysis of their COI-DNA barcodes. The aphid individuals will be identified based on their morphological characters and secondary host plants, then the target sequence of their DNA will be amplified using aphid-specific primers and corresponding polymerase enzymes. The phylogenetic relationship of the species will be determined by cluster analysis. The research will be completed with faunal survey of root feeding aphids as possible competitors of the D. devecta complex. Entry requirements: Excellent academic performance; master’s degree in biology, ecology or a related discipline; very good English language skills. Background in entomology and/or traditional or molecular taxonomy is an advantage.

2020-09-01

2024-08-01

abszolutóriumot szerzett

Surveying the Dysaphis devecta species-complex in Europe