caa a22 4500 386361118 CHVBK 20180307111915.0 cr unu---uuuuu 161130e198907 xx s 000 0 eng 10.4039/Ent121569-7 doi S0008347X00031825 pii (NATIONALLICENCE)cambridge-10.4039/Ent121569-7 DISTRIBUTION OF BARBARA COLFAXIANA (KEARFOTT) (LEPIDOPTERA: TORTRICIDAE) EGGS WITHIN AND AMONG DOUGLAS-FIR CROWNS AND METHODS FOR ESTIMATING EGG DENSITIES [Elektronische Daten] The 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. Copyright © Entomological Society of Canada 1989 Sweeney J.D. Forestry Canada, Pacific Forestry Centre, 506 West Burnside Road, Victoria, British Columbia, Canada V8Z 1M5 Miller G.E. Forestry Canada, Pacific Forestry Centre, 506 West Burnside Road, Victoria, British Columbia, Canada V8Z 1M5 The Canadian Entomologist Cambridge University Press 121/7(1989-07), 569-578 0008-347X 121:7<569 1989 121 TCE https://doi.org/10.4039/Ent121569-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.4039/Ent121569-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sweeney J.D. Forestry Canada, Pacific Forestry Centre, 506 West Burnside Road, Victoria, British Columbia, Canada V8Z 1M5 NATIONALLICENCE 700 1- Miller G.E. Forestry Canada, Pacific Forestry Centre, 506 West Burnside Road, Victoria, British Columbia, Canada V8Z 1M5 NATIONALLICENCE 773 0- The Canadian Entomologist Cambridge University Press 121/7(1989-07), 569-578 0008-347X 121:7<569 1989 121 TCE CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge