Contents: By Damage and Image
(In progress)
Contents: Alphabetical
alder flea beetle
aphid management
apple and thorn skeletonizer
apple ermine moth
ash whitefly New
azalea bark scale
azalea lace bug
azalea sawfly New
bark lice
Barypeithes root weevil Updated
Beneficial nematodes
biocontrol of root weevils
birch aphid Updated
black bean aphid New
black cherry aphids New
black stem borer
bluegum psyllid
borers
branch and twig borer
brown marmorated stink bug

bronze birch borer
boxwood leafminer
boxwood psyllid Updated
bulb flies
cabbage whitefly new
carpet beetle (images)
Calligraph californica
caterpillars

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

dogwood sawfly
Douglas fir sawfly
Douglas fir twig weevil
dustywings New
earwigs
elm leafminer
European pine shoot moth
European wool carder bee
emerald ash borer
Fall webworm
flatheaded cedar borer
ground beetle gallery New
hollyhock weevil
honeylocust plant bug
honeylocust pod gall midge
Heliothis phloxiphaga
holly bud moth
huckleberry root aphids
ground mealybug
Japanese beetle New
lacebugs
lacewings New
lady beetle gallery Updated
leaf weevil
light brown apple moth
maple aphids Updated
maple tip moth
maple midge
March flies Updated
mountain ash sawfly
Narcissus bulb fly Updated
Natural enemies gallery new
spruce twig aphid
oak ambrosia beetle
oak slug
oak twig gall wasp new
obscure root weevil
Pacific flatheaded borer
peach tree borer
peach twig borer
pear blight beetle Updated
pear psylla
pear leaf-curling midge
pear sawfly
pine needle scale
pine and cone spittlebug New
poplar and willow borer
rose curculio weevil
rose midge
roseslug
rove beetle gallery New
sawflies
scale
sequoia pitch moth
soldier beetle gallery New
snakefly gallery New
speckled green fruitworm
meadow spittlebug updated
tent caterpillars
thrips
viburnum leaf beetle
violet gall midge
western poplar clearwing
western spotted cucumber beetle
white pine weevil Updated
whiteflies
woolly ash aphid
woolly beech aphid Updated

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Ash Whitefly

Update: Key ash whitefly parasites and predators have been found in Oregon!
These natural enemies may provide almost complete control of this whitefly pest as they have in other states where they have been found in association with ash whitefly. Click here for the ODA story.

Handout from Ash Whitefly Information Session for Nurseries Oct 8 NWREC

Listen to my interview about ash whitefly with Mike Darcy on In the Garden [from Saturday 10-3-2015, starts at 41 minutes into the recording].

 

The ash whitefly, Siphoninus phillyreae (Haliday), was detected in Oregon in 2014. Late summer/fall flights of ash whiteflies have been noticed in both 2014 and 2015 in the Willamette Valley. They are beginning to swarm as well in 2016 during September. The whitefly has a wide host range which includes many ornamentals, native plants, and fruit trees. Little is know of how impactful will be this newly detected insect in Oregon but it is not too soon to begin to monitor for the whitefly on both known (see Nguyen and Hamon, 2000; Bellows et al. 1990) and unreported hosts.

Distribution
Ash whitefly was first detected in California in 1988 and has since been detected in Arizona, Florida (2010), Georgia, Nevada, New Mexico, North Carolina (1993), and South Carolina.

Description
The adults have light yellow bodies which are covered by white wings. Ash whitefly eggs are pale waxy yellow and often surrounded by waxy deposits. Young nymphs are nearly translucent but become more opaque and covered in tufts of white wax. The puparia are covered with tufts of white wax and have tubercules or long tubes formed around the edge of their bodies topped with clear waxy droplets.

Biology
The adult female typically lives for about 30-60 days. Female whiteflies lay eggs on the undersides of the leaves on host plants. Nymphs emerge from the eggs and settle onto the leaves where they remain and feed on the plant sap. They then pupate and later emerge as winged adults. There are four juvenile stages of the whitefly between the egg and adult stages. Both the nymph and adult stages can feed. At 77°F the whitefly can develop from egg to adult stage in 25 days (Bellows et al. 1990). The ash whitefly can develop continuously during the year although development slows with cooler temperatures. There can be several generations per year. The whiteflies tend to move from preferred deciduous summer hosts such as ash, pear, and hawthorn to evergreen overwinter hosts. All stages of the whitefly can overwinter on evergreen host plants.

Monitoring
The whitefly may be flying right now (September) onto evergreen hosts on which it will overwinter. Shaking or tapping branches over which whitefly are flying is one way to monitor. Another is to slowly turn over a branch, twig, or leaf and examine for whitefly adults and juvenile stages of the whitefly. Various juvenile stages (eggs, nymphs, puparia) of the whitefly on a plant indicates it is able to reproduce on the host plant. These are plants that will be more susceptible to direct damage (curling tips, stunting, defoliation) as well as indirect damage (honeydew and sooty mold) from the whitefly. While the overwintering adult stage may not directly damage a plant, it might be a shipment contaminant pest and intervention may be required if plant shipments occur while the whitefly is present.

Biological Control
Several biological control agents have been released in other states to manage populations of ash whitefly including a parasitic wasp Encarsia inaron (= partenopea?) and a lady beetle, Clitostethus arcuatus. The most successful agent limiting the populations of ash whitefly in California was the tiny wasp, E. inaron, which was found in emergence rates from ash whitefly nymphs at 80 to 98%. In Florida, E. inaron was also found to be effective as a parasite of ash whitefly.

Chemical Control
Recommendations for ash whitefly management have yet to be developed specifically for Oregon nursery production. If management is required, refer to the nursery section in the PNW Insect Management Handbook for general whitefly management recommendations.

Resources:

Bellows T, Paine T, Gould J, Bezark L, Ball J, Bentley W, Coviello R, Downer J, Elam P, Flaherty D, Gouveia P, Koehler C, Molinar R, O'Connell N, Perry E, Vogel G. 1992. Biological control of ash whitefly: a success in progress. Cal Ag 46(1):24-28.

Bellows T, Paine T, Arakawa K, Meisenbacher C, Leddy P, Kabashima J. 1990. Biological control sought for ash whitefly. Cal Ag 44(1):4-6. <5 October 2015>

Nguyen, Ru and Avas B. Hamon. 2000. Featured Creatures: Ash Whitefly. Florida Department of Agriculture and Consumer Services. August 2000. (18 September 2015).

Paine, T., Bellows, T. and M. Hoddle. 2009. Ash whitefly. Center for Invasive Species Research. (18 September 2015).

Original version: <10 October 2015)

Last revision <20 September 2016>

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

Ash whitefly adult
ash whitefly adult

Ash whitefly eggs and puparium
ash whitefly eggs and puparium

Early instars nymphs and puparium of ash whitefly
early instar nymphs of ash whitefly

Older instar nymphs of ash whitefly
older instar nymphs of ash whitefly

Ash whitefly puparia and empty puparia
ash whitefly puparia and empty puparia

Closeup of ash whitefly puparia and empty puparia
ash whitefly puparia and empty puparia

Encarsia inaron, a parasitic wasp of ash whitefly
Encarsia inaron

Clitostethus arcuatus, lady beetle predator of ash whitefly
Clitostethus arcuatus

Website editor:
Robin Rosetta


 

Page last modified 9/20/16

 

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