Beneficial insects could provide valuable pest control services on Oregon Christmas tree farms, but a limited amount of data exist that quantifies the type and abundance of beneficial insects on farms. This study surveyed beneficial insects on two farms that differed in their management strategies as well as other abiotic...
Beneficial insects could provide valuable pest control services on Oregon Christmas tree farms, but a limited amount of data exist that quantifies the type and abundance of beneficial insects on farms. This study surveyed beneficial insects on two farms that differed in their management strategies as well as other abiotic...
The balsam woolly aphid (Adelges piceae (Ratz)), an
European pest of conifers, was first discovered in the
Pacific Northwest shortly after 1930. Control measures
of a chemical, silvicultural, or biological nature have
been proposed. However, present control methods are either
too costly or do not result in satisfactory control of...
Published March 1936. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published February 1926. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published April 1941. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Wild proso millet (Panicum miliaceum L.) is a serious weed
recently infesting sweet corn fields in the Willamette Valley of
western Oregon. Field and greenhouse experiments were conducted to
determine the importance of seed depth in the position of the growing
point of wild proso millet seedlings and in the...
The dynamics of tansy ragwort, Senecio jacobaea L. , and the cinnabar moth, Tyria jacobaeae (L.) were studied with the aid of a system simulation model. The model development and validation were based on knowledge of the plant and herbivore gathered from the literature, four years of data from previous...
Hand-defoliation was evaluated for its ability to
simulate herbivory by cinnabar moth larvae, Tyria
jacobaeae (L.) (Arctiidae) on the weed tansy ragwort,
Senecio jacobaea L. (Asteraceae). The evaluation was done
on a field population of flowering ragwort, for three
different timings (early, middle, and late season) of
damage.
In the...
To determine which isolates will most rapidly replace
Phellinus weirii in stumps and roots, Trichoderma spp. were
isolated from P. weirii-infested stumps and roots, identified, and
examined for growth rates and lethal effects on P. weirii in vitro.
Phellinus weirii-infested Douglas-fir stumps and stump roots
were sampled for microorganisms by...
Laboratory studies were conducted to evaluate the effects of prey
availability on prey consumption, survivorship and oviposition of the
southern pine beetle predator, Thanasimus dubius Fabricius. Although
prey consumption rates were significantly affected by the sex, size and
ovipositional status of the predator, it was found through correlation
analyses that...
Published October 1982. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
A classical biological control project was undertaken
against the filbert aphid, Myzocallis coryli (Goetze), in
western Oregon. Hazelnut orchards in Spain, France, and
Italy were searched for natural enemies of the aphid, and
a parasitic wasp, Trioxys pallidus Haliday, was imported,
quarantined, mass-reared, and released in Oregon orchards.
The wasp...
We identified and evaluated a phytoseiid predator as a biological control agent of multiple spider mites pests that occur in ornamental nurseries. When comparing species, Neoseiulus fallacis (Garman) had a wider prey range than Galendromus occidentalis (Nesbitt), a higher probability of overwintering than Neoseiulus califomicus McGregor and was equally or...
Published June 1991. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
This study evaluated the effects of tillage system, rotational tillage sequences, and winter seed burial depth on weed seedling recruitment in irrigated cropping systems. Notill (NT) planting of vegetable crops reduced emergence of hairy nightshade by 77 to 99% and Powell amaranth emergence from 50 to 87% compared to conventional...
Published September 1989. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published April 1966. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
The feasibility of managing codling moth, Cydia pomonella (L.), with mixtures
of Bacillus thuringiensis-based microbial and selected chemical insecticides was
studied under laboratory and field conditions. Joint actions (synergism, additivity and
antagonism) of these mixtures were determined for both egg and larval stages. Higher
rates of microbial control agents (MCAs),...
The cytolytic properties of the mosquitocidal 25 Kd protein deltaendotoxin of Bacillus thuringiensis subsp. israelensis (Bti) was studied using the human erythrocyte as a target cell. Both a fixedtime and a kinetic hemolytic bioassay were developed in order to screen a variety of treatments for their influence on the toxinerythrocyte...
Five field experiments were conducted to evaluate the relative attractiveness of potential beneficial insectary plants to aphidophagous hover flies and parasitic Hymenoptera and the effectiveness of interplanting selected flowering plants in a broccoli field to enhance biocontrol of the cabbage aphid and green peach aphid. In 1996 we established a...
Cheatgrass (Bromus tectorum L.) and yellow starthistle (Centaurea
soistitialis L.) have invaded over 3 million ha of grasslands in the western U.S.
Future management will require an understanding of the conditions,
mechanisms, and processes which control species dominance, community
dynamics, and desirable plant establishment in these alien dominated annual
rangelands....
To assess the effect of summer moisture stress on the capacity of tansy ragwort (Senecio jacobaea L.) to compensate for defoliation by the cinnabar moth (Tyria jacobaeae LT7), the performance of plants grown under different irrigation regimes was measured. The proportion of plants producing
new leaves following defoliation, the number...
Isolates of Trichoderma spp. collected from snap bean foliage were tested for inhibition of grey mold of snap beans caused by Botrytis cinerea. In a detached blossom-pod assay an isolate of Trichoderma hamatum reduced pod rot by 94% compared to the nontreated check. Control was comparable to that obtained with...
Large raspberry aphid, Amphorophora agathonica, is an important pest in red and black raspberries in the Pacific Northwest. It transmits plant viruses that cause decreased cane vigor and fruit quality, making it a significant pest for growers. This publication includes aphid identification, biology, monitoring techniques, and control methods.
Dalmatian toadflax (Linaria dalmatica) has become a prolific invasive plant of rangelands in Oregon since its arrival in the early 20th century. In 2001, the Oregon Department of Agriculture initiated a release program promoting the distribution of the stem-boring weevil, Mecinus janthinus as classical biological control agent to reduce densities...
The cinnabar moth (Tyria jacobaeae (L.), Lepidoptera: Arctiidae) is an icon in
population ecology and biological control that has recently lost its shine based on evidence
that (1) it is less effective than alternatives (such as the ragwort flea beetle Longitarsus
jacobaeae (Waterhouse) (Coleoptera: Chrysomelidae) for controlling ragwort Senecio
jacobaea...
Numbers of invertebrates (except family Carabidae) collected from pitfall and refuge traps in ten Annual Ryegrass fields in Linn County, Oregon between March 23, 2018 and June 20, 2019. Given are details on sampling date, site and trap ID, trap type, taxonomy (at least order level) and life stage.
The azalea lace bug (Stephanitis pyrioides Scott) is a recently detected invasive pest to the Pacific Northwest and has become a major concern in Oregon. It feeds on azaleas as well as rhododendrons causing stippling on the top side of leaves. The damage is aesthetically displeasing and affects plant vigor...
The purpose of this study was to determine the present status
of introduced parasites of the omnivorous leaf tier, Cnephasia
longana (Haworth) in Oregon.
The omnivorous leaf tier is native to Europe. It was introduced
into North America around 1929 and became a serious pest of economic
crops such as...
Field experiments were done to test the relative
effectiveness of single and multiple biological control
agents in reducing weed populations using two insects, the
cinnabar moth, Tvria iacobaeae (L.), and the ragwort flea
beetle, Lonqitarsus iacobaeae (Waterhouse). These two
insects were released for biological control of the biennial weed tansy...
In the first part of this study we monitored the development of biological control
of purple loosestrife Lythrum salicaria over a six-year period at Morgan Lake in western
Oregon. In 1992, two beetles, Galerucella pusilla and G. calmariensis (Coleoptera:
Chrysomelidae), were released to control the wetland weed at this test...
Yeast biocontrol agents that were applied to 'Bose' and 'Anjou' pears in the field up to three weeks prior to harvest were found to survive on the fruit at high population levels on both pear varieties. Cryptococcus infirmo-miniatus, Cryptococcus laurentii, and Rhodotorula glutinis maintained populations averaging 5 x 10⁶ cfu/fruit...
Specialist and generalist phytoseiid mites are widely used for biological
control of spider mites. Understanding dispersal attributes of these mites is
important to implementing more stable, cost-efficient integrated pest management.
In this regard, we studied dispersal of phytoseiid mites from a local ambulatory
phase of movement within a prey patch...
Invasive plants threaten ecosystems and economies worldwide. Classical biological control, introduction of specialist herbivores on invasive plants, is one of the tools employed to reduce the impact of invasive plants. Gorse, Ulex europaeus L. (Fabaceae), an invasive leguminous shrub, is the target of a biological control program in Oregon. The...
Potato (Solanum tuberosum L.) is the fourth largest food crop in the world following rice (Oryza sativa L.), wheat (Triticum spp.), and maize (Zea mays subs. mays). Potatoes arrived in the United States in the early 1600s and over the following centuries, the crop was subsequently cultivated across the country...
Radial colony growth of three isolates of Gliocladium roseum and three isolates of Bottytis cinerea were measured on 1/4 strength potato dextrose agar amended with concentrations of NaHCO₃ ranging from 0-2% (w/v). Compared to the control, reductions in colony diameter of the B. cinerea isolates ranged from 60-79% and 73-89%...
Seasonal synchrony between the filbert aphid,
Myzocallis coryli (Goetze) and its newly introduced
parasitoid Trioxys pallidus Haliday was examined in the
field to evaluate the effectiveness of parasitoid based
biological control in filbert orchards of Oregon. Fieldemergence
observations showed that 50% eclosion of the aphid
occurred 14 days before that...
Pergamasus quisquiliarum Canestini is a polyphagous predatory mite that has been shown to feed on the economically important arthropod, Scutigerella immaculata Newport (Symphyla: Scutigerellidae), Collembola, Diptera larvae, Enchytraeid worms, and miscellaneous other soil organisms. This study examined the feeding behavior of P. quisquiliarum, the effects of cover cropping and tillage...
The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is the most devastating foliage-feeding pest of potatoes in the United States. Potential biological control agents include the nematodes Heterorhabditis marelatus Liu & Berry and Steinernema riobrave Cabanillas, Poinar & Raulston, which provided nearly 100% CPB control in previous laboratory trials. In...
The cinnabar moth, Tyria jacobaeae (L.) (Lepidoptera:Arctiidae), was released in 1959 to control the grassland weed tansy ragwort, Senecio jacobaea L. (Asteraceae), despite evidence that caterpillars of this species can feed on native plants within the genera Senecio and Packera. Previous studies confirmed the moth's ability to develop on the...
Published May 1981. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
The biocontrol potential of Trichoderma harzianum strains
B-2A, B-8A, B-4B, B-15B, and B-41 and Serratia plymuthica was
evaluated using agar plates and wood wafers of unseasoned
ponderosa pine (Pinus ponderosa laws). All five isolates of
Trichoderma harzianum and Serratia plymuthica could inhibit
stain fungi growth in agar plates and exhibited...
The leaf surface is a stark environment for bacterial colonists with limited
availability of nutrients, water and protected niches. Despite these limitations, a
plethora of bacteria appear to have adapted ways to survive and flourish on leaf
surfaces. One mechanism of survival is the formation of biofilms. Biofilms are a...
In horticultural nurseries for container-grown plants, production and sales have been threatened by the presence of a quarantined plant pathogen, Phytophthora ramorum (causal agent of sudden oak death). Infested nursery beds are an important source of P. ramorum, which can initiate disease through movement with surface water to infect roots...
Eight phylloplane yeasts were isolated from backyard apple trees in Corvallis, OR. Yeast isolates were classified to genus or species level. All isolates were tested in vitro for antagonistic activity against the postharvest pathogens Botrytis cinerea and Penicillium expansum. Of these isolates, Aureobasidium pullulans, Sporobolomyces roseus Rhodotorula sp., consistently reduced...
The cards in this guide are designed to help
you quickly learn the main groups of natural
enemies of crop and garden pests, their
predacious activity, and tips for observing them.
Photographs are of the most common species in
the Pacific Northwest.
The toxicity of menthol, menthone, pulegone, limonene, and a-pinene, five monoterpenes found in peppermint (Mentha piperita L.), to the variegated cutworm (Peridroma saucia Hiibner) was characterized by in vivo and in vitro methods. Pulegone and menthone caused slower growth over six days when incorporated into an artificial diet and fed...
The genome of the multicapsid nuclear polyhedrosis virus of
Orgyia pseudotsugata (OpMNPV) was mapped by examining overlapping
Hindlll fragments from cosmid clones which had been constructed
from partial Hindlll digests of viral DNA. Five OpMNPV cosmid
clones containing fragments encompassing the entire OpMNPV genome
were hybridized to blots of DNA...
Antagonistic effects of Epicoccum purpurascens,
Aureobasidium pullulans, Trichoderma spp., and Botrytis
cinerea on establishment of Monilinia fructicola infections
in cherry and peach blossoms were assessed in field and mist
chamber studies. Conidia of each fungus were applied to
blossoms that were subsequently inoculated with conidia of
M fructicola. Mist chamber...
This thesis addressed the potential of endemic predaceous and parasitic arthropods of
the Hood River Valley, Oregon to suppress the pear psylla, Cacopsylla pyricola F8rster.
Natural enemies adequately suppressed psylla in three of seven unsprayed orchards of
differing vegetational settings, orchard age, and size. Relatively few psylla natural enemies
dispersed...
Hippodamia convergens Guerin-Meneville was selected for
rapid development through five generations at four constant
temperatures (18, 22, 26, and 30°C). Two levels of selection
were used: intense and moderate. Differences in developmental
rate, survivorship, live adult weight, aphid consumption,
adult longevity, and fecundity were measured for both groups
and an...
The life history, temperature, humidity, and feeding requirements of the
phytoseiid predator mite, Typhlodromus americanus Chant and Yoshida-Shaul were
tested in the laboratory. Occurance of the mite in the field during different times of the
year was investigated as well. Effects of temperature and humidity on egg hatch, the
feeding...
Pseudomonas is a diverse genus of Gamma proteobacteria that are ubiquitous in the natural environment, including soil, water, plant surfaces, and animals. The Pseudomonas fluorescens group is a diverse collection of seven subgroups and more than 50 named species. This group is known for their production of a variety of...
Purple loosestrife is a wetland perennial that came to the eastern seaboard of
North America in ship ballast and raw wool in the 1800's. Since coming to the
United States, it has spread across the country, forming dense monospecific stands
in wetlands. Mechanical and chemical control was expensive and ineffective,...
Several aspects affecting population trends and overwintering of Neoseiulus
fallacis (Garman) on peppermint were examined. Neoseiulus fallacis was the most
abundant phytoseiid predator mite found in peppermint surveys throughout the western U.S. Results of pesticide exclusion and cage studies showed that N. fallacis controlled Tetranychus urticae (Koch) on peppermint in...
The biocontrol potential of Trichoderma harzianum Rifai,
Trichoderma polysporum (Link.:Pers.) Rifai, Scytalidium aurantiacum
Klingstr. et Beyer or a Penicillium sp. against Trametes versicolor
(L. :Fr.) Pilat, Neolentinus lepideus (Fr.) Redh. et Ginns, Postia
placenta (Fr.) M.Lars. et Lomb. and Irpex lacteus Fr. was evaluated
using agar plate, soil bottle and...
While microbial colonization of wood is presumed to be characterized by a myriad of interactions between numerous organisms, studying these processes is often difficult owing to the opaque nature of the wood and the inability to readily distinguish among the many species colonizing the material. One method for enhancing the...
A study consisting of three parts was undertaken to investigate how variation in species interactions, population genetic structure, epidemiological parameters, and plant breeding system may influence the ecology and biological control of an apomictic invasive plant, Chondrilla juncea (Asteraceae). Interactions between natural enemy species may modify their net effect on...