DISTRIBUTION OF CONTARINIA OREGONENSIS FOOTE (DIPTERA: CECIDOMYIIDAE) EGGS IN DOUGLAS-FIR SEED ORCHARDS AND A METHOD OF ESTIMATING EGG DENSITY

1986 ◽  
Vol 118 (12) ◽  
pp. 1291-1295 ◽  
Author(s):  
G.E. Miller
Keyword(s):  
Negative Binomial ◽  
Gall Midge ◽  
Average Density ◽  
Douglas Fir ◽  
Worst Case ◽  
Seed Orchards ◽  
Egg Density ◽  
Optimum Sampling ◽  
Sampling Procedures ◽  
Individual Trees

AbstractEfficient sampling procedures for estimating densities of eggs of Douglas-fir cone gall midge (DFCGM), Contarinia oregonensis Foote, on individual trees as well as for orchards were developed from data collected in Douglas-fir seed orchards in 1978–1981. Egg distribution was contagious and generally fitted the negative binomial distribution on individual trees, but a common k could not be estimated. Tree and crown level affected density of midge eggs within orchards. Average density at the midpoint of the cone-bearing portion of the crown was not significantly different from the tree average. The optimum sampling pattern in an orchard, i.e. one conelet from the midpoint of the cone-bearing portion of each of 120 trees, would require 120 person-hours to process the samples when DFCGM egg densities are high (worst-case situation).

DISTRIBUTION OF BARBARA COLFAXIANA (KEARFOTT) (LEPIDOPTERA: TORTRICIDAE) EGGS WITHIN AND AMONG DOUGLAS-FIR CROWNS AND METHODS FOR ESTIMATING EGG DENSITIES

1989 ◽  
Vol 121 (7) ◽  
pp. 569-578 ◽  
Author(s):  
J.D. Sweeney ◽  
G.E. Miller
Keyword(s):  
Negative Binomial ◽  
Sequential Sampling ◽  
Critical Density ◽  
Optimal Number ◽  
Douglas Fir ◽  
Seed Orchards ◽  
Frequency Distributions ◽  
Seed Loss ◽  
Control Threshold ◽  
Egg Density

AbstractThe spatial and frequency distributions of Douglas-fir cone moth, Barbara colfaxiana (Kearfott), eggs in Douglas-fir trees and stands were determined by dissecting 13 262 conelets collected from 81 trees in three sites and 2 years. There were no consistent trends in egg density associated with crown level or aspect. The frequency distribution of eggs per conelet fitted the negative binomial in three of five site-years but a common k for the negative binomial could not be calculated. Green’s index of aggregation suggested that the cone moth egg distribution was significantly aggregated in each site-year.The optimal number of conelets per tree to sample was determined to be four in forest stands and three in seed orchards. The number of sample trees required for estimating mean egg density with 10% and 20% precision and 90% confidence was calculated for a range of mean egg densities using the method of Kuno. The sample sizes required to estimate a control threshold density of 0.6 eggs per conelet with 10% precision and 90% confidence were very large and would be impractical for operational use. Therefore, a sequential sampling plan was developed for use in seed orchards that would classify cone moth egg densities as either above or below a critical density at which 10% seed loss would be expected.

EVALUATION OF FOUR CHEMICAL INSECTICIDES REGISTERED FOR CONTROL OF THE DOUGLAS-FIR CONE GALL MIDGE, CONTARINIA OREGONENSIS (DIPTERA: CECIDOMYIIDAE), AND THE DOUGLAS-FIR SEED CHALCID, MEGASTIGMUS SPERMOTROPHUS (HYMENOPTERA: TORYMIDAE), IN DOUGLAS-FIR SEED ORCHARDS

1986 ◽  
Vol 118 (11) ◽  
pp. 1185-1191 ◽  
Author(s):  
John D. Stein ◽  
George P. Markin
Keyword(s):  
Gall Midge ◽  
Douglas Fir ◽  
Pairwise Comparisons ◽  
Seed Orchards ◽  
Significant Difference

AbstractOxydemeton-methyl, azinphosmethyl, dimethoate, and acephate were evaluated in Douglas-fir seed orchards for control of Douglas-fir cone gall midge, Contarinia oregonensis Foote, and Douglas-fir seed chalcid, Megastigmus spermotrophus Wachtl. Results varied with infestation levels and specific chemicals. There was no significant reduction of infestation levels of either insect with the application of acephate. Oxydemeton-methyl injections, oxydemeton-methyl spray, and dimethoate significantly reduced cone gall midge damage. All four chemicals were ineffective against the seed chalcid for infestations of less than 10% of extractable seed. Oxydemeton-methyl injections, azinphosmethyl, and dimethoate significantly reduced the incidence of seed chalcid when the infestation was high (61%). There was no statistically significant difference (α = 0.05) for pairwise comparisons between chemicals which significantly reduced the infestation levels of either insect.

DAMAGE PREDICTION FOR CONTARINIA OREGONENSIS FOOTE (DIPTERA: CECIDOMYIIDAE) IN DOUGLAS-FIR SEED ORCHARDS

1986 ◽  
Vol 118 (12) ◽  
pp. 1297-1306 ◽  
Author(s):  
G.E. Miller
Keyword(s):  
Sequential Sampling ◽  
Gall Midge ◽  
Critical Density ◽  
Sampling Technique ◽  
Average Density ◽  
Douglas Fir ◽  
Damage Prediction ◽  
The Mean ◽  
Optimum Sample ◽  
Filled Seeds

AbstractDamage at cone harvest by the Douglas-fir cone gall midge, Contarinia oregonensis Foote, was positively correlated with the number of egg-infested scales per conelet in the spring. Reducing the average number of galled seeds per cone by 1.5 increased the average number of filled seeds per cone by 1.0 in insecticide trials. Optimum sample sizes for estimating average densities of egg-infested scales were calculated to be one conelet per tree and 150 trees per orchard. The mean crowding variable was linearly related to average density so a sequential sampling technique relative to a critical density, using Iwao’s procedure, was developed for determining the need of control actions.

CONE AND SEED INSECTS IN DOUGLAS-FIR, PSEUDOTSUGA MENZIESII (MIRB.) FRANCO, SEED ORCHARDS IN THE WESTERN UNITED STATES: DISTRIBUTION AND RELATIVE IMPACT

1985 ◽  
Vol 117 (10) ◽  
pp. 1223-1230 ◽  
Author(s):  
T.D. Schowalter ◽  
M.I. Haverty ◽  
T.W. Koerber
Keyword(s):  
Pseudotsuga Menziesii ◽  
Gall Midge ◽  
Douglas Fir ◽  
Western United States ◽  
Seed Orchards ◽  
Or Management ◽  
Dioryctria Abietivorella ◽  
Explained Variation ◽  
Cone And Seed Insects ◽  
Seed Insects

AbstractDouglas-fir cones were collected from 17 seed orchards in California, Oregon, and Washington in the fall of 1983. Cones were completely dissected and seed losses ascribed to the Douglas-fir cone gall midge (Contarinia oregonensis (Foote)), the Douglas-fir seed chalcid (Megastigmus spermotrophus (Wachtl)), the Douglas-fir cone moth (Barbara colfaxiana (Kearfott)), and the fir coneworm (Dioryctria abietivorella (Groté)). There appear to be great differences between orchards, but overall C. oregonensis and M. spermotrophus collectively destroyed approximately 70% of the filled seed. Physiographic province significantly (P<0.05) explained variation in damage by all insect species between seed orchards. In general, damage by all species increased from northern provinces to southern mountainous provinces. Damage by C. oregonensis and B. colfaxiana appeared to be related to land use or management factors, as well.

The Stability of Weed Seedling Population Models and Parameters in Eastern Nebraska Corn (Zea mays) and Soybean (Glycine max) Fields

Weed Science ◽  
1995 ◽  
Vol 43 (4) ◽  
pp. 604-611 ◽  
Author(s):  
Gregg A. Johnson ◽  
David A. Mortensen ◽  
Linda J. Young ◽  
Alex R. Martin
Keyword(s):  
Negative Binomial Distribution ◽  
Binomial Distribution ◽  
Negative Binomial ◽  
Sequential Sampling ◽  
Mean Value ◽  
Distribution Model ◽  
Ratio Test ◽  
Weed Species ◽  
Sampling Procedures ◽  
Grass Weed

Intensive field surveys were conducted in eastern Nebraska to determine the frequency distribution model and associated parameters of broadleaf and grass weed seedling populations. The negative binomial distribution consistently fit the data over time (1992 to 1993) and space (fields) for both the inter and intrarow broadleaf and grass weed seedling populations. The other distributions tested (Poisson with zeros, Neyman type A, logarithmic with zeros, and Poisson-binomial) did not fit the data as consistently as the negative binomial distribution. Associated with the negative binomial distribution is akparameter.kis a nonspatial aggregation parameter related to the variance at a given mean value. Thekparameter of the negative binomial distribution was consistent across weed density for individual weed species in a given field except for foxtail spp. populations. Stability of thekparameter across field sites was assessed using the likelihood ratio test There was no stable or commonkvalue across field sites and years for all weed species populations. The lack of stability inkacross field sites is of concern, because this parameter is used extensively in the development of parametric sequential sampling procedures. Becausekis not stable across field sites,kmust be estimated at the time of sampling. Understanding the variability in it is critical to the development of parametric sequential sampling strategies and understanding the dynamics of weed species in the field.

A Biodegradable Formulation of MCH (3-Methylcyclohex-2-en-1-one) for Protecting Pseudotsuga menziesii from Dendroctonus pseudotsugae (Coleoptera: Curculionidae) Colonization

2020 ◽  
Vol 113 (4) ◽  
pp. 1858-1863 ◽  
Author(s):  
Gabriel G Foote ◽  
Christopher J Fettig ◽  
Darrell W Ross ◽  
Justin B Runyon ◽  
Tom W Coleman ◽  
...  
Keyword(s):  
New Mexico ◽  
Pseudotsuga Menziesii ◽  
Tree Mortality ◽  
Douglas Fir ◽  
Dendroctonus Pseudotsugae ◽  
Individual Tree ◽  
Significant Difference ◽  
Antiaggregation Pheromone ◽  
Individual Trees

Abstract Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, trees and stands can be protected from Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins (DFB)-caused mortality by application of synthetic formulations of the beetle’s antiaggregation pheromone, 3-methylcyclohex-2-en-1-one (MCH). A biodegradable formulation of MCH, SPLAT MCH, was developed and evaluated for protecting individual Douglas-fir trees and small stands from colonization and mortality by DFB. In an individual-tree experiment in Idaho, both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of treated trees colonized and killed by DFB compared to untreated controls. SPLAT MCH was as effective as MCH bubble capsules for protecting individual trees. Both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of trees colonized and killed by DFB within 0.04-ha circular plots surrounding each treated tree compared to untreated controls. In 0.41 ha stands in New Mexico, both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of trees colonized and killed by DFB compared to untreated controls, again with no differences observed between MCH treatments. In a similar stand level trial in Idaho, neither MCH treatment significantly reduced the proportion of trees colonized by DFB, and only MCH bubble capsules significantly reduced levels of tree mortality compared to untreated controls, but no significant difference was observed between SPLAT MCH and MCH bubble capsules. Overall, the results indicate that SPLAT MCH is as effective as MCH bubble capsules for protecting individual trees and small stands of Douglas-fir from DFB-caused mortality.

PREVENTION OF INSECT-CAUSED SEED LOSS IN DOUGLAS-FIR WITH SYSTEMIC INSECTICIDES

1966 ◽  
Vol 42 (1) ◽  
pp. 76-82 ◽  
Author(s):  
A. F. Hedlin
Keyword(s):  
Insect Pests ◽  
Gall Midge ◽  
Vancouver Island ◽  
Douglas Fir ◽  
Systemic Insecticides ◽  
Seed Loss ◽  
Stage Of Development

Cone-bearing Douglas-fir trees in three localities on Vancouver Island were sprayed with the systemic insecticides Bidrin (0.35 and 0.75%), dimethoate, Sumithion, Meta-Systox-R, and SD 9129 (1.0 and 2.0%) when cones had reached the pendent stage of development. With the exception of Sumithion, all materials gave varying degrees of control over important insect pests of cones in this area, i.e. the gall midge, Contarinia oregonensis Foote, the cone moth, Barbara colfaxiana (Kft.), the seed chalcid, Megastigmus spermotrophus Wachtl, and the scale midge, C. washingtonensis Johnson.

scholarly journals Heuristic Optimization of Thinning Individual Douglas-Fir

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 280
Author(s):  
Todd West ◽  
John Sessions ◽  
Bogdan M. Strimbu
Keyword(s):  
Genetic Algorithm ◽  
Monte Carlo ◽  
Tabu Search ◽  
Douglas Fir ◽  
Growth And Yield ◽  
Computationally Efficient ◽  
Expectation Values ◽  
High Productivity ◽  
Land Expectation Value ◽  
Individual Trees

Research Highlights: (1) Optimizing mid-rotation thinning increased modeled land expectation values by as much as 5.1–10.1% over a representative reference prescription on plots planted at 2.7 and 3.7 m square spacings. (2) Eight heuristics, five of which were newly applied to selecting individual trees for thinning, produced thinning prescriptions of near identical quality. (3) Based on heuristic sampling properties, we introduced a variant of the hero heuristic with a 5.3–20% greater computational efficiency. Background and Objectives: Thinning, which is arguably the most subjective human intervention in the life of a stand, is commonly executed with limited decision support in tree selection. This study evaluated heuristics’ ability to support tree selection in a factorial experiment that considered the thinning method, tree density, thinning age, and rotation length. Materials and Methods: The Organon growth model was used for the financial optimization of even age Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) harvest rotations consisting of a single thinning followed by clearcutting on a high-productivity site. We evaluated two versions of the hero heuristic, four Monte Carlo heuristics (simulated annealing, record-to-record travel, threshold accepting, and great deluge), a genetic algorithm, and tabu search for their efficiency in maximizing land expectation value. Results: With 50–75 years rotations and a 4% discount rate, heuristic tree selection always increased land expectation values over other thinning methods. The two hero heuristics were the most computationally efficient methods. The four Monte Carlo heuristics required 2.8–3.4 times more computation than hero. The genetic algorithm and the tabu search required 4.2–8.4 and 21–52 times, respectively, more computation than hero. Conclusions: The accuracy of the resulting thinning prescriptions was limited by the quality of stand measurement, and the accuracy of the growth and yield models was linked to the heuristics rather than to the choice of heuristic. However, heuristic performance may be sensitive to the chosen models.

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