Russian Knapweed Acroptilon repens L.


Puccinia acroptili
P. & H. Syd.

DESCRIPTION: Rust-colored pustules
BACKGROUND LIFE CYCLE
Availability Habitat Adult Emergence Egg Laying Larva Development F1 Adult Life Span Over Winters
G Most areas where host plant grows Early spring 12 to 16 days after innoculation On stems and leaves Covers surface of stems and leaves Continuous N/A On rosette leaves
ATTACK COLLECTION NOTES
Stage Damage Life Stage Method Pustule produced spores are easily spread by wind and water
Pustules -Infestation limits photosynthesis to leaves and stemInfected plant material August to SeptemberClip infected stem or leaves


Subanguina picridis
Kirj. & Ivan

DESCRIPTION: Nematode-not visible to unaided eye
BACKGROUND LIFE CYCLE
Availability Habitat Adult Emergence Egg Laying Larva Development F1 Adult Life Span Over Winters
N Sites with cool moist spring weather Spring-juveniles require 1 month prior to becoming infective In 5 to 12 mm galls during host plant growth stage In galls on leaves, stems and root collar   3 weeks Leaves, stem, root collar
ATTACK COLLECTION NOTES
Stage Damage Life Stage Method Gall formation generally only occurs at sites with cool, moist spring weather.
Juveniles and adult -Galls/leaves stem root collarGalls in springClip or dig plant material


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