Dichotomous table for gallers on Callistephus chinenis
(comp. Aster)
by Hans Roskam
1a On leaves and shoot => 2
1b Lateral roots with 2–4 mm long, ± spindle-shaped swellings, with some partially adventitious roots. Meloidogyne hapla
2a Malformations by aphids and spittlebugs => 3
2b Stems of young plants very much shortened, spongy, swollen, bushy clustered; petioles of basal- or stem leaves, sometimes including the under leaf blade areas galled in a similar way. Ditylenchus dipsaci
3a Malformations by aphids => 4
3b Leaves on the stunted and ± bent stem nest-like converging; curled and dark green close to the froth-covered nymph. Philaenus spumarius
4a Malformation, curling and curving of apical young leaves, caused by yellowish or greenish aphids => 5
4b Similar malformations caused by black aphids. Aphis fabae
5a Malformations by yellowish to bright green aphids lacking segmentally arranged brown dots on the dorsal surface. Brachycaudus helichrysi
5b Adult apterous aphids yellowish, possessing segmentally arranged brown dots on the dorsal surface. Myzus ornatus