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 new
sequoia pitch moth
soldier beetle gallery
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 ash aphid
woolly beech aphid

Back to Home

Contact Us

There are various methods to manage root weevils by using biological control. Check the beneficial nematode link for more information on the use of entomopathogenic nematodes for various soil pests including root weevils. One of the biological control methods is the use of the entomopathogenic fungus, Metarhizium anisopliae. This fungus is available as a commercial product for use in nurseries, Met 52 (Novozymes Biologicals). There are several important factors to of relevance regarding this fungal product.

Link to Met 52 label

This product has a Caution label based on an oral and dermal LD50 >5000 mg/kg. The re-entry interval (REI) is 4 hours for this product. According to the label, there is no REI for uses that are incorporated. The product is composed of the fungal spores on a grain matrix. Once the product is incorporated into the growing medium, insects may come into contact with infective spores, which adhere to surface of insect, germinate, and cause an infection of the insect and death within 3-5 days.

At the USDA-ARS Horticultural Crops Research Laboratory in Corvallis, Oregon, Dr. Denny Bruck has investigated some interesting aspects of this soil insect-killing fungus. The fungus is rhizosphere competent, meaning the fungus shows enhanced growth around developing roots even in absence of a host insect. Inoculation of the roots of spruce, Picea abies, with M. anisopliae spores successfully infected 76% of last-instar black vine weevil that fed on the roots (Bruck 2005).

There is a gradual decline of fungal density over time but after more than four months, the decline was slower in peat-based media than bark-based media. Pre-mixing one-third of the total volume of the potting media with the full amount of product seven days prior to planting (at which time the remaining volume of potting mix was added), allowed for higher populations of the fungus than media not pre-mixed and that lasted throughout the length of his research trial (342 days).  One word of caution is that temperatures above 100F will kill the spores.  

In another experiment, Bruck and Donahue (2007) evaluated persistence of M. anisopliae, the granular Met 52 formulation was incorporated into a soilless potting medium and measured for infectivity of black vine weevils over time. The percentage of larval infectivity started at a high of 90% at week 3 and persisted with a mean infectivity of 50-60% for the duration of the experiment, which lasted 77 weeks. The infection rate tended to increase (75-89%) during the cool wet months of the fall and winter.

Fungicide compatibility was also assessed and while a number of fungicides had significant effect on spore germination and mycelial growth in vitro, no detrimental impact on M. anisopliae populations was seen in bulk soils following dual applications of the fungicides. Captan and triflumizolet (Terraguard), with shorter reapplication intervals (less than 14 days), did have a detrimental impact on M. anisopliae populations in the rhizosphere, and thus may not be compatible in a program using M. anisopliae treatments (Bruck 2009).


Bruck, D.J. 2005. Ecology of Metarhizium anisopliae in soiless potting media and the rhizosphere: Implications for pest management. Biological Control 32:155-163.

Bruckk, D.J. and K.M Donahue. 2007. Persistence of Metarhizium anisopliae incorporated into soiless potting media for control of the black vine weevil, Otiorhynchus sulcatus in container-grown ornamentals. Journal of invertebrate Pathology 95:146-150.

Bruck, D. J. 2009. Impact of fungicides on Metarhizium anisopliae in the rhizosphere, bulk soil and in vitro. Biocontrol 54:597-606.


Website editor:
Robin Rosetta

Page last modified 5/13/10


Before applying any of the information found on this site, please read our disclaimer.
Copyright © 2019, All Rights Reserved

Oregon State University Extension Service prohibits discrimination in all its programs, services, activities, and materials on the basis of race, color, national origin, religion, sex, gender identity (including gender expression), sexual orientation, disability, age, marital status, familial/parental status, income derived from a public assistance program, political beliefs, genetic information, veteran’s status, reprisal or retaliation for prior civil rights activity.
El Servicio de Extensión de Oregon State University prohíbe la discriminación en todos sus programas, servicios, actividades y materiales en base a la raza, color, origen nacional, religión, sexo, identidad de género (incluyendo la expresión de género), orientación sexual, discapacidad, edad, estado civil, estatus de la familia/padres, ingresos derivados de un programa de asistencia pública, creencias políticas, información genética, estado de veterano, represalia o represalia por actividad previa de los derechos civiles.