cornflower

synonym: Centaurea cyanus

organ parasitic mode stage note taxonomic group parasite
unknown borer larva Apionidae Ceratapion basicorne
leaf vagrant summer generation Aphididae Aphis fabae fabae
leaf down Peronosporales Bremia centaureae
leaf vagrant summer generation Aphididae Aphis fabae
systemic vagrant Aphididae Protaphis terricola
systemic borer Anguinidae Ditylenchus dipsaci
fruit gall Tephritidae Urophora quadrifasciata
flower borer Tephritidae Chaetostomella cylindrica
flower borer Tephritidae Trupanea stellata
flower gall doubtful Tephritidae Urophora aprica
leaf down Erysiphales Golovinomyces depressus
leaf down Erysiphales Golovinomyces montagnei
leaf down Erysiphales Podosphaera xanthii
leaf down Peronosporales Bremia lactucae
leaf miner Agromyzidae Phytomyza spinaciae
leaf miner Depressariidae Agonopterix subpropinquella
leaf pustule aecia Pucciniales Puccinia caricis-montanae
leaf pustule uredinia telia Pucciniales Puccinia cyani
leaf pustule uredinia telia Pucciniales Puccinia jaceae
stem borer Agromyzidae Ophiomyia curvipalpis
root collar borer Apionidae Ceratapion penetrans
root gall Meloidogynidae Meloidogyne hapla
leaf vagrant Aphididae Paczoskia obtecta
leaf vagrant summer generation Aphididae Brachycaudus helichrysi
flower vagrant Aphididae Uroleucon jaceae

Organ

the part of the plant that most conspicuously is hit by the parasite

all buds: both flower buds and leaf buds
flower: also inflorescence
leaf: also needle, phyllodium, petiole
leaf bud: also unfolding young leaf
fruit: also seed
root: also root stock, runners
root collar: also the lowest part of the stem
stem: also culm, the lower part of the peduncle, in grasses also leaf sheath
systemic: the entire above-ground plant.

PARASITIC MODE

borer: larva living internally, almost no outwards signs
down: 0.5-2 mm high fungal down
film: very thin cover of fungal tussue
gall: swelling and/or malformation
grazer: feeding at the outside of the plant
leaf spot discoloured, often ± necrotic, generally not galled, sign of a fungus infection
miner-borer: larve initially makes a mine, lives as a borer later
pustule: plug of fungal tissue, generally brown-black and < 2 mm
stripe: longitudinal line of fungal tissue in a grass leaf
vagrant: (aphids, mites) living freely on the plant, at higher densitiy causing malformations.

IMPORTANT

The host plant spectre of a parasite is rarely known exhaustively; this applies in particular at the species level. It is advisable therefore to check at least also the list of all parasites of this genus.

 

mod 14.iv.2019