IDH

Western Blackheaded Budworm

Source: http://cfs.nrcan.gc.ca/images/5442

Hosts & Range (click to expand)

	H, B (Ss, Sx, Fd)
	common in the CWH (western VI, QCI, north coast) and ICH
	prefers stands that are mature, dense with a heavy Hw component (~80+%) tree: upper crowns of dominant & co-dominant sites: cool and moist

	Source: http://www.for.gov.bc.ca/tasb/legsregs/fpc/fpcguide/defoliat/fig5.htm
	Note outbreak area vs. distribution

	Source: http://www.na.fs.fed.us/spfo/pubs/silvics_manual/volume_1/tsuga/heterophylla.jpg

Life Cycle / Biology (click to expand)

	eggs laid late summer / early fall on needles of branch tips in upper crown singly on underside of needles look like egg yolks (I like 'em over easy)

	Source: http://www.fs.fed.us/r10/spf/fhp/leaflets/Blaheabud5.jpg
	larva hatch in May / June greenish and have a dark head and thoracic shield naked feed on emerging buds (= new foliage) loose webbing at branch tips Source: http://cfs.nrcan.gc.ca/images/5442
	prefer younger foliage, but will move to older foliage in an outbreak when all young foliage consumed
	pupate in late July / August
	adults emerge in August

	Source: http://www.forestryimages.org/images/768x512/0805021.jpg

Signs & Symptoms (click to expand)

	insect - eggs: single 'egg yolks' on needle - larva: naked, green with black head - pupa: naked - adult: grey-brown wings
	tree - bud mining in spring, then on flushing buds with some webbing - crowns go red-brown (scorched) - heaviest defol. in upper crown - dead tops
	stand - 0-1400 m

Damage (click to expand)

	Outbreaks occur every 10-15 years Coast - often with hemlock sawfly Interior - often with hemlock looper
	heavy feeding at top of tree
	top kill if outbreak is sustained on same trees (2-3 years) - often up to 3 m
	mortality not common, but can occur in prolonged severe outbreak (3-4 years)

	Source: http://www.forestryimages.org/images/768x512/0177068.jpg

	Source: http://www.forestryimages.org/images/768x512/0177070.jpg
	damage is heaviest when outbreak of the blackheaded budworm coincides with the hemlock sawfly hemlock sawfly is a wasteful feeder and readily consumes older foliage
	growth loss, deformation, predisposition

Management (click to expand)

	Annual overview surveys
	if population building bud mining surveys in spring to confirm pop'n level and need for treatment larval surveys later in season to confirm treatment and determine efficacy
	Short Term Action Btk - apply during outbreak ... ... if suffered one year of moderate-severe defol. and next year is predicted at mod.-severe ... ... i.e. two years of mod-severe defol. is unacceptable
	Long Term Mgmt ... classic stuff ... maintain a thrifty stand (spacing & possibly fertilization ($$)) promote a species mix