Patrick J. Shea

MCH Released in a Novel Pheromone Dispenser Prevents Spruce Beetle, Dendroctonus rufipennis (Coleoptera: Scolytidae), Attacks in South-central Alaska

Field tests of 3-methyl-2-cyclohexen-1-one (MCH), the antiaggregation pheromone of the spruce beetle, Dendroctonus rufipennis Kirby, were conducted in south-central Alaska in stands of Lutz spruce, Picea x lutzii Little, and Sitka spruce, P. sitchensis (Bong.) Carr. The deployment of MCH in a novel releaser significantly reduced trap catches and spruce beetle attacks on standing live spruce by 96 and 87%, respectively. The results of this study demonstrate the first successful field test of MCH in Alaska for the prevention of spruce beetle attacks on standing, live spruce.

Proceedings of the sudden oak death second science symposium: the state of our knowledge

The Sudden Oak Death Second Science Symposium provided a forum for current research on sudden oak death, caused by the exotic, quarantine pathogen, Phytophthora ramorum. Ninety papers and forty-six posters on the following sudden oak death/P. ramorum topics are included: biology, genetics, nursery and wildland management, monitoring, ecology, and diagnostics. Several papers on P. kernoviae and other forest Phytophthora species are also presented.

Effects of cholinesterases of rainbow trout exposed to acephate and methamidophos

Determination de limportance de la depression de la cholinesterase cerebrale associee a diverses concentrations dacephate, et du temps necessaire pour le retour de cette cholinesterase a la normale apres cette derpession. Etablissement des concentrations tissulaires dacephate associees au parametre ci-dessus. Etude identique realisee avec le methamidophos a cause de la possibilite de ldesacylation de lacephate en methamidophos

Toxicity of acephate and methamidophos to dark-eyed juncos.

The calculated, acute oral LD50 of acephate and methamidophos to dark-eyed juncos (Junco hyemalis) was 106 mg/kg and 8 mg/kg, respectively. Brain cholinesterase (ChE) activity in birds that died after acephate poisoning was depressed 80% below that of control birds. Birds that died of acute methamidophos poisoning had brain ChE depression of 60%. The birds killed by acephate had brain acephate residue concentrations greater than 2 mg/kg and methamidophos concentrations usually greater than 0.25 mg/kg. Eighty percent of the birds killed with methamidophos had brain methamidophos concentrations greater than 0.1 mg/kg. The five-day feeding LC50 for acephate was 1485 mg/kg. Brain ChE activities of birds which died early in the study were less depressed (51.5%) than those which died at a later date (69.6%). Brain residues of acephate and methamidophos were lower in these birds than in the birds of the acute oral LD50 studies. Brain ChE activity returned to normal within three days after the birds received a single sublethal dose of acephate. These studies indicate that the amount of acephate needed to produce the ChE depression found in other investigations in most dark-eyed juncos exposed to forest applications of insecticide is about one-fifth of the LD50; however, in a few birds the ChE activity may be depressed to near lethal levels.

Mass-Balance of Pheromone Surrogate Plumes in the Canopy Trunk Space

A large, multi-year study has been completed to evaluate the dispersion of insect pheromone in forest canopy ntrunk spaces. The study was undertaken to guide operational pest managers in the placement of pheromone sources in nforest canopies. A very dense network of tracer sampling devices was deployed and over 200 average (half-hourly) nplumes consisting of over 13000 chemical samples are available for analysis. This spatially dense near-field array nprovides an important opportunity to conduct a mass balance exercise. The subset of tests analyzed here indicates that nmass recovery in this situation is possible within a factor of two and often close to 100%, though even in this dense nsampler field there is substantial uncertainty and a tendency to over recover (>100%).

Near-Field Trunk Space Dispersion

A near-field tracer study was conducted to study the movement and dispersion of gas in the lower forest ncanopy in an attempt to improve guidance for forest managers deploying anti-aggregation pheromone sources to protect nhigh value forest stands. Data are shown from three forest canopies and include over 13000 chemical tracer samples ncompiled into half hour dispersion fields around a point source. A high frequency sampler was also deployed to ascertain nthe structure of the gas plumes at 1 Hz. The plumes showed strong Gaussian tendencies in many cases and very high npeak-to-mean ratios. Average maximum ÷/Q values were relatively consistent over the canopies studied though high nvariance in the maximum ÷/Q values was observed.