Contents: By Damage and Image
In progress
Contents: Alphabetical

alder flea beetle
aphid management
apple and thorn skeletonizer
apple ermine moth
ash whitefly
azalea bark scale
azalea lace bug
azalea sawfly
Bagrada bug
bark lice
Barypeithes root weevil
Beneficial nematodes
biocontrol of root weevils
birch aphid
black bean aphid
black cherry aphids
black stem borer
bluegum psyllid
Boisduval scale
branch and twig borer
brown marmorated stink bug

bronze birch borer
boxwood leafminer
boxwood psyllid
bulb flies
cabbage whitefly
carnation tortrix
carpet beetle (images)
Calligraph californica

Ceanothus stem gall moth
cereal leaf beetle
cherry ermine moth
chilli thrips
cinnabar moth
clay colored weevil
cottony camellia scale

crane flies
cypress tip moth

dogwood sawfly
Douglas fir sawfly
Douglas fir twig weevil
elm leafminer
European pine sawfly new
European pine shoot moth
European wool carder bee
emerald ash borer
Fall webworm
fir coneworm new
flatheaded cedar borer
ground beetle gallery
Hemerocallis gall midge new
hollyhock weevil
honeylocust plant bug
honeylocust pod gall midge
Heliothis phloxiphaga
holly bud moth
huckleberry root aphids
ground mealybug
Japanese beetle
lady beetle gallery
leaf weevil
light brown apple moth
Linden aphid new
lupine aphid new
Macrosiphum rhamni new
maple aphids
maple tip moth
maple midge
March flies
mountain ash sawfly
Myzocallis sp. on red oak new
Narcissus bulb fly
natural enemies gallery
oak ambrosia beetle
oak slug
oak twig gall wasp
obscure root weevil
Pacific flatheaded borer
peach tree borer
peach twig borer
pear blight beetle
pear psylla
pear leaf-curling midge
pear sawfly
pine needle scale
pine and cone spittlebug
poplar and willow borer
Psyllopsis fraxinicola
rose curculio weevil
rose midge
rove beetle gallery
rose stem girdler
sequoia pitch moth
soldier beetle gallery
snapdragon plume moth new
snakefly gallery
speckled green fruitworm
meadow spittlebug
spotted asparagus beetle
spruce twig aphid
tent caterpillars
viburnum leaf beetle
violet gall midge
western poplar clearwing
western spotted cucumber beetle
white pine weevil
woolly alder aphid new
woolly ash aphid
woolly beech aphid

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Woolly beech aphid

The woolly beech aphid, Phyllaphis fagi, is an introduced aphid which can be found on Fagus sylvatica. Growers report seeing them on several cultivated varieties including Fagus sylvatica'Asplenifolia', 'Fastigiata', 'Roseo-Marginata' and 'Purpurea

Young aphid nymphs have been found to hatch (eclose) from overwintering eggs before bud break (Iverson and Harding, 2007). In Oregon we have had reports as early as mid-April but they become more noticeable in May. These aphids will feed and soon reach adult stages. They reproduce without mating (parthenogenesis) so populations of aphids on the spring growth can enlarge rapidly. As many as 10 generations were documented in nursery production (Iverson and Harding, 2007). Winged (alates) aphids are produced for months and winged populations peak in mid-June. No significant difference in reproductive fecundity was seen between winged and wingless females (Iverson and Harding, 2007). Winged males mate with wingless females in the fall. Those females lay eggs on stems which overwinter.

Monitor for the eggs near buds and the aphids on new growth and leaf undersides.

For information on management of aphids, check the PNW Insect Management Handbook.


Nice images can be found at Woolly beech aphid

There is a discussion of woolly beach aphid at the plante doktor website.

Iversen, T. and Harding, S. (2007), Life table parameters affecting the population development of the woolly beech aphid, Phyllaphis fagi. Entomologia Experimentalis et Applicata, 123: 109–117. doi:10.1111/j.1570-7458.2007.00524.x <24 Mar 2016>

Fan-dancing woolly beech aphids - video


Orginal publication 4/20/06
Lastest revision <8 May 2017>

Author: R.L. Rosetta, Extension Nursery Integrated Pest Management, Department of Horticulture, Oregon State University/NWREC.

Woolly beech aphid eggs on stem
woolly beech aphid eggs
Photo: Rosetta
A white tuft near the yellow arrow shows the small size of the aphid.
woolly beech aphid on leaf underside
Photo: Rosetta
A microscopic shot of an aphid on the leaf underside. The "wool" has been knocked off of the aphid in transport.
woolly beech aphid
Photo: Rosetta
A colony of woolly beech aphid. Note honeydew near aphid.
woolly beech aphid colony
Woolly beech aphid colony in late June
Woolly beech aphid colony
Woolly beech aphid colony in mid-May
woolly beech aphids
Photo: Rosetta, Oregon State University
Website editor:
Robin Rosetta

Page last modified 5/8/17


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