A study of the host range and distribution of ticks and chiggers
(Acari) was undertaken in two contrasting forested areas of western
Oregon. Acarines were sampled from host mammals which were
trapped along line transects laid out in both areas, each consisting of
18 stations 50 feet apart. Hosts were...
The communicative behavior of five species and subspecies of
Tropisternus Solier (Coleoptera: Hydrophilidae) was studied. These
aquatic beetles have stress and calling chirps (both sexes), a second
male calling signal (one species), a single male courtship sound
(usually), a male copulatory sound, and a female aggressive rejection
buzz (three species)....
The western cherry fruit fly, Rhagoletis indifferens
Curran, was studied to determine the suitability of the
sterile insect technique for its control. To obtain
insect material, field collection of maggots is preferred
to sifting of soil or rearing on artificial diet.
The western cherry fruit fly is strictly univoltine;
only...
The purpose of this study was to examine various host and microclimatic influences affecting the survival and development of the flatheaded fir borer, Melanophila drummondi (Kirby) in Douglas fir, Pseudotsuga menziesii (Mirbel) Franco residues. It also expands current knowledge of the biology, bionomics, life history, ecology, and biotic potential for...
Prothoracicotropic hormone has been partially purified
from whole heads of tobacco hornworm larvae, Manduca sexta.
Activity was followed with a larval bioassay. Activity was
purified 4400 fold from crude extracts. The hormone was
found to be a heat-stable polypeptide with an approximate
molecular weight of 25,000 Daltons. The hormone has...
Aggregation and species association of 9 species of phytophagous and
predaceous mites were studied for 6 yr in an orchard with 100, 2 m tall 'Red
Delicious' apple trees. To quantify aggregation, a method was developed that is
powerful, and easily interpreted. It relates the proportion of habitat occupied to...
Behavioral responses exhibited by the Douglas-fir beetle,
Dendroctonus pseudotsugae Hopkins, to various attractant sources
were investigated under both laboratory and field conditions. Tests
were designed to observe olfactory responses. Results were correlated
and compared with collections from sampling nets and with
emergence patterns. Field data were collected during the flight...
The early stages of secondary succession of the
McDonald and Paul Dunn State Forests, Corvallis, Oregon,
were grouped into three stages; herb, herb-shrub, and
shrub, based on vegetation types. Flowers of herbaceous
species and residual shrubs dominated in the early years
after clear-cutting. Woody plants became increasing
abundant in the...
Meadowfoam (cultivar Mermaid) is an entomophilous
winter annual oilseed crop that has historically produced
an average of only two of five seeds per flower. Reference
to inadequate meadowfoam pollination exists in the literature,
but quantitative evidence is lacking. Studies were
undertaken to: 1) quantify meadowfoam pollination requirements
and 2) evaluate...
The probing behavior and feeding activity of green peach aphid, Myzus persicae
Sulzer, on Bacillus thuringiensis ssp. tenebrionis- transgenic potatoes, insecticide
treated potatoes, and host plants with different preference were electronically
monitored. I found that first, transgenic potatoes had no effect on green peach aphid
probing suggesting that transmission of...
The eruption of Mt. St. Helens provided the
opportunity to study secondary production of grazing insects in the context of disturbance. Two stream sites were chosen that significantly differed in how their
watersheds were impacted by the eruption. Clearwater Creek was catastrophically disturbed (physical alteration of habitat, loss of riparian...
Biology of Scaptomyza apicalis Hardy (Diptera: Drosophilidae) was studied in
relation to its host, meadowfoam, Limnanthes alba, a recent oil seed crop grown in the
Willamette Valley, Oregon. Populations of flies and larvae were monitored weekly over
three consecutive crop-years beginning in 1996. Yellow sticky traps gave relative
population estimates...