Dichotomous table for gallers on Asparagus
by Hans Roskam
1a On A. officinalis => 2
1b On A. acutifolius, aphyllus. Young twigs irregularly swollen and curved, terminally with tufts of compressed leaves with broadened bases, discoloured or reddish. Overwintering buds variously abnormally hypertrophied. Containing flesh-coloured larvae: Dasineura turionum
1c Usually the whole shoot, just after budding, is transformed into a gall. Leaf scales are swollen and broadened at base. The white midge larvae are located under the swollen scales. A. acutifolius, albus, tenuifolius: Dasineura minardii
1d Fruits changed into spongy mass. A. aphyllus: Dasineura sp.
2a On above-ground parts => 3
2b Roots with nodular swellings. A. officinalis: Meloidogyne hapla
3a On vegetative parts => 4
3b Flower buds globular, perianth succulent, swollen, dark-green; not opening. Containing several white- to orange larvae. A. officinalis: Contarinia florum
4a Stunting of stems with terminal green shoots; caused by aphids => 5
4b Stem of young, pale or greened shoots crippled. Tip ± curved, crooked, dying off early. Often several yellowish-white larvae, up to 10 mm long in extended tunnels. A. officinalis: Plioreocepta poeciloptera
4c Terminally distorted and discoloured spines of young twigs transformed into swellings with broadened base. Gregarious white larvae between the spines. A. acutifolius, aphyllus, officinalis: Dasineura asparagi
5a Leaves of solitary or of several neighbouring shoot tips accumulated densely like bottle brushes, shortened, ± rounded, rigid, dark green; with colonies of grey-powdered aphids in between. A. aethiopicus, densiflorus, officinalis: Brachycorynella asparagi
5b Similar malformations; however more loosely tuft-like; leaves softer, ± downwardly deflected. Aphid black. Asparagus spp.: Aphis fabae