Dichotomous table for gallers on Bunias
by Hans Roskam
1a On flowers or leaves => 3
1b On root collar or on roots => 2
2a Rotund, succulent, usually one-sided, one-chambered gall, up to 8 (10) mm long, on root collar. Containing a single larva. B. erucago. Ceutorhynchus assimilis
2b Roots with conspicuous, succulent, compact swellings, with masses of minute spores in many cells. B. erucago, orientalis: Plasmodiophora brassicae
3a On leaves => 4
3b Flower buds swollen, unopened. Containing a single or several whitish to pale yellow, jumping larvae. B. erucago, orientalis: Contarinia nasturtii
4a Malformations caused by animal inducers => 5
4b Leaf blades of younger leaves often close to main venation with minor, pale green upward swellings; on the underside with a white down of branched conidiophores. B. orientalis: Peronospora buniadis
5a Basal leaves with expanded loose downward rolls, usually on one side. Infected leaf blade parts ± bumpy, arched, darker green; on underside a single or several froth-covered nymphs. B. orientalis: Philaenus spumarius
5b Petioles or axis with spindle-shaped swellings, 10–15 mm long, also deep green inside. Containing a single larva. B. erucago: Ceutorhynchus chalybaeus