Beauty & the Blast ( Bud Blast )

Fri, 06/23/2017 - 15:10 -- Admin
Resources
Education

Rhododendron bud and twig blight is caused by a fungus, Seifertia azalea. The flower buds turn brown and do not open in the spring. They are later covered by very noticeable black fruiting bodies called coremia the year after infection. Removal of the black buds is recommended if possible.

The rhododendron leafhopper, Graphocephala sp. is implicated in these infections by some researchers. It lays its eggs by making slits in rhododendron buds in the fall allowing entry of the fungus into these sites.

The feeding activities of the adults and nymphs have no obvious adverse effect on the appearance of the foliage or the plant's vigour. Female leafhoppers make egg incisions in next year's flowers buds in late summer-autumn. The fungal disease, known as bud blast (Seifertia azalea), is thought to infect the buds through the egg wounds, although RHS notes that some recent research has placed doubt on this assumption. The fact is: Infected flower buds turn brown and die.

The American Rhododendron Society notes Bud Blast does not seem to attack all plants. In fact, there are only a few, usually with R. catwabiense in their background, that are affected.

Control

  • We do not recommend chemical controls due to toxicity to other insects.
  • Sunset Western Garden Problem Solver suggests control of leafhopper may be had by spraying the affected leaves with a strong blast of water from a hose.  Natural predators of leafhoppers include birds, beneficial Green Lacewing larvae, and parasitoid wasps.
  • Flower buds infected with bud blast should be picked off and disposed of to reduce the amount of fungal spores being released in the vicinity of the plants.

Rhs.org Rhododendron leafhopper and bud blast

http://oregonstate.edu/dept/nurspest/Briosia.htm

http://www.rhododendron.org/news/plantsv6n1.htm

See our article from a few years ago where we identified this insect

Information compiled by: H. Nielsen, Vancouver Chapter

More to read

PEST ALERT: Japanese Beetle found in False Creek
News | August 18, 2017
in MGABC
MEMBERS: MGABC AGM Sept 23/24th Vancouver
News | August 18, 2017
in MGABC
Fire Smart Landscaping
Resources | July 12, 2017
in Victoria
Fire Smart Landscaping in Drought Interface Areas
Resources | July 12, 2017
in Vancouver
Beauty & the Blast ( Bud Blast )
Resources | June 23, 2017
in Vancouver

Community Events

September 24, 2017
Education | Victoria
Creating a Cut Flower Garden Workshop - Fall
September 25, 2017
Garden Club Meeting | Victoria
Victoria Orchid Society
September 26, 2017
Garden Club Meeting | Victoria
Mill Bay Garden Club
September 27, 2017
Garden Club Meeting | Victoria
Victoria Cactus & Succulent Society
September 27, 2017
Garden Club Meeting | Victoria
Sooke Garden Club
September 28, 2017
Garden Club Meeting | Victoria
Victoria Chrysanthemum Society
October 01, 2017
Garden Club Meeting | Victoria
Vancouver Island Rock and Alpine Garden Society
October 02, 2017
Garden Club Meeting | Victoria
Victoria Rhododendron Society
October 02, 2017
Garden Club Meeting | Victoria
Gordon Head Garden Club
October 03, 2017
Garden Club Meeting | Victoria
Victoria Horticultural Society