An in vitro assessment of phylloxera (Daktulosphaira vitifoliae Fitch) (Hom., Phylloxeridae) life cycle

Phyiloxera single founder lineages were maintained in an aseptic, dual-cult ure system to investigate the phylloxera life cycle, focusing on holocycle induction. Holocyclic morphs were developed on the grape rootstock 41B and they produced vital sexuales. The morphological development of sexual stage s was studied and an assessment of genetic variation within a single founde r lineage was performed. Twenty individual phylloxera of differing stages ( apterous parthenogenetic, pre-sexual nymphs, sexuparae and sexuals) were ge netically fingerprinted using amplified fragment length polymorphism-polyme rase chain reaction technology. Four individuals displayed differing bandin g patterns, exhibiting three different independent genotypes. No influence of the morphal stage on these patterns could be detected. This study did no t achieve phylloxera matings. However, the system could serve as a tool for future studies, performing controlled and systematic crosses and back-cros ses to examine Mendelian genetics.