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)....
A population of the Douglas-fir cone moth, Barbara colfaxiana
(Kft. ), was studied on the Buckhead Seed Production Area, Oakridge,
Oregon, during 1971 and 1972. A method of estimating cone and
insect populations is presented. Factors contributing to the mortality
of B. colfaxiana are discussed, with resinosis being the critical...
Out of 53 queens captured for initiating colonies in the
laboratory, 33 laid eggs (62 percent), 29 of these produced colonies
(55 percent), and 14 produced queens (26 percent). A behavioral model
depicts the activities of queens from spring emergence through colony
development. A discussion of its application to bumble...
Loss of early instar Douglas-fir tussock moth (Orgyia pseudotsugata McDunnough) (DFTM) has been found to constitute 66-92% of intra-generation mortality and to be a key factor in inter-generation population change. This death has been attributed to dispersal and to arthropod predation, two factors previously judged more important to an endemic...
Interactions between Bacillus sphaericus and Bacillus
thuringiensis israelensis (Bti), persistence of insecticidal
activity in the mosquito habitat, and suitability of enzyme-linked
immunoabsorbent assay (ELISA) for detecting and
quantifying bacterial endotoxin in the mosquito habitat were
investigated. Interactions between the two bacterial
species were examined by laboratory and field bioassays with...
Thirteen New World populations of Megachile rotundata and M. apicalis and
two Old World populations of M. rotundata were analyzed at 23 enzyme loci using
cellulose acetate electrophoresis. Conventional and G- or C-banded karyotypes were
also examined in these populations. The principal findings are (1) No differences
were found in...
The objective of this study was to ascertain the magnitude and
distribution of rainfall over coastal waters of the northwestern United
States and to compare values with those at nearby land stations.
Precipitation was measured with gauges at Totem, rainfall amounts
were assessed from weather reports at lightships off the...
Hydrographic, tidal, and meteorological data collected near
Newport, Oregon, were analyzed to determine the relative contributions
of temperature, salinity, and air pressure variations to the
recorded departures of sea level from mean sea level.
Nearshore the steric and recorded sea levels exhibited a
similar seasonal oscillation, with high sea levels...
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...