Insects Affecting Seed Production in Red Pine: Part I Conophthorus resinosae Hopk. (Coleoptera: Scolytidae)

Natural and artificial reforestation, which basically depend on an abundance of sound seed, are adversely affected when insects destroy large numbers of cones, seeds, and cone-bearing shoots. Other factors, such as unfavourable weather, incomplete seed development, and damage by birds and mammals also reduce seed production, but they are rarely of such widespread importance as insects, whose damage often results in the failure of seed crops over large areas. Cone and seed insects sometimes restrict the natural regeneration of trees for a few years at a time, as, for example, in conifers on the Pacific coast (16), loblolly pines in Virginia (13), and oak in Michigan (5), but they become particularly important when the seeds they destroy are required for use in artificial reforestation. The future success of much reforestation, which is inclining more and more toward the use of seed obtained from trees cultivated especially for that purpose, may largely depend on a thorough understanding of cone and seed insects and their effect on seed production.

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DISPERSAL OF CONE AND SEED INSECTS TO AN ISOLATED DOUGLAS-FIR TREE IN WESTERN OREGON

The Canadian Entomologist ◽

10.4039/ent1161437-10 ◽

1984 ◽

Vol 116 (10) ◽

pp. 1437-1438 ◽

Cited By ~ 3

Author(s):

T. D. Schowalter

Keyword(s):

Pacific Northwest ◽

Gall Midge ◽

Douglas Fir ◽

Control Measures ◽

Host Trees ◽

The Pacific ◽

Major Species ◽

Insect Populations ◽

Cone And Seed Insects ◽

Seed Insects

Cone and seed insects frequently cause severe losses to Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seed production in the Pacific Northwest (Hedlin et al. 1981; Ruth 1980). Two of the major species west of the Cascades are the Douglas-fir cone gall midge (Contarinia oregonensis Foote (Diptera: Cecidomyiidae)) and the Douglas-fir seed chalcid (Megastigmus spermotrophus Wachtl. (Hymenoptera: Torymidae)). These two species are host specific on Douglas fir and exhibit an extended diapause in which more than 50% of each year's cohort may remain in diapause under host trees for 1 or more years (Annila 1982; Hedlin 1961; Hedlin et al. 1981; Johnson 1962). The economic and biological costs of chemical control have supported recommendation of alternative control measures, particularly (1) establishing seed orchards some distance from sources of coneand seed-insect populations, and (2) removing all cones and burning litter as a means of reducing such populations (Hedlin et al. 1981; Ruth 1980). The success of these two options depends on the dispersal strategies of cone and seed insects (Johnson 1962), but information on dispersal has been lacking. The purpose of this study was to obtain such information.

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Climatic dipoles drive two principal modes of North American boreal bird irruption

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1418414112 ◽

2015 ◽

Vol 112 (21) ◽

pp. E2795-E2802 ◽

Cited By ~ 22

Author(s):

Courtenay Strong ◽

Benjamin Zuckerberg ◽

Julio L. Betancourt ◽

Walter D. Koenig

Keyword(s):

North America ◽

Seed Production ◽

Warm Season ◽

Bird Populations ◽

Continental Scale ◽

The North ◽

Large Numbers ◽

Seed Eating ◽

One Year ◽

Seed Crops

Pine Siskins exemplify normally boreal seed-eating birds that can be sparse or absent across entire regions of North America in one year and then appear in large numbers the next. These dramatic avian “irruptions” are thought to stem from intermittent but broadly synchronous seed production (masting) in one year and meager seed crops in the next. A prevalent hypothesis is that widespread masting in the boreal forest at high latitudes is driven primarily by favorable climate during the two to three consecutive years required to initiate and mature seed crops in most conifers. Seed production is expensive for trees and is much reduced in the years following masting, driving boreal birds to search elsewhere for food and overwintering habitat. Despite this plausible logic, prior efforts to discover climate-irruption relationships have been inconclusive. Here, analysis of more than 2 million Pine Siskin observations from Project FeederWatch, a citizen science program, reveals two principal irruption modes (North-South and West-East), both of which are correlated with climate variability. The North-South irruption mode is, in part, influenced by winter harshness, but the predominant climate drivers of both modes manifest in the warm season as continental-scale pairs of oppositely signed precipitation and temperature anomalies (i.e., dipoles). The climate dipoles juxtapose favorable and unfavorable conditions for seed production and wintering habitat, motivating a push-pull paradigm to explain irruptions of Pine Siskins and possibly other boreal bird populations in North America.

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Development of a Seismic Microzoning Map for Lima City and Callao, Peru

Journal of Disaster Research ◽

10.20965/jdr.2014.p0939 ◽

2014 ◽

Vol 9 (6) ◽

pp. 939-945 ◽

Cited By ~ 1

Author(s):

Diana Calderon ◽

◽

Zenon Aguilar ◽

Fernando Lazares ◽

Silvia Alarcon ◽

...

Keyword(s):

Mechanical Characteristics ◽

Pacific Coast ◽

Soil Samples ◽

S Wave ◽

Seismic Microzoning ◽

Geophysical Exploration ◽

Large Numbers ◽

The Pacific ◽

History Of ◽

Microtremor Measurements

The location of Lima city and El Callao in the Pacific coast and the long history of seismic activity were the main reasons to develop a seismic microzoning map. The microzoning study was based on large numbers of geotechnical and geophysical exploration points distributed around the study area. The geotechnical exploration consisted of borehole tests and pits, from which soil samples were taken to the laboratory to determine the soil mechanical characteristics. The geophysical exploration consisted of onepoint microtremor measurements and various methods to estimate the S-wave velocity profile. The results of both, the geotechnical and geophysical exploration were combined to develop a seismic microzoning map for Lima city and El Callao. This map shows five zones, where the zone with the best soil mechanical and dynamic characteristics covers most of the study area.

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Bacterial Blight in Carrot Seed Crops in the Pacific Northwest

Plant Disease ◽

10.1094/pd-89-0896 ◽

2005 ◽

Vol 89 (8) ◽

pp. 896-907 ◽

Cited By ~ 9

Author(s):

Lindsey J. du Toit ◽

Fred J. Crowe ◽

Mike L. Derie ◽

Rhonda B. Simmons ◽

Gary Q. Pelter

Keyword(s):

Pacific Northwest ◽

Seed Production ◽

Daucus Carota ◽

Bacterial Blight ◽

Xanthomonas Campestris ◽

The Pacific ◽

Carrot Seed ◽

Direct Seeded ◽

Clean Seed ◽

Seed Crops

Carrot (Daucus carota subsp. sativus) seed crops in Oregon and Washington were surveyed in 2001-02 and 2002-03 for development of Xanthomonas campestris pv. carotae, causal agent of bacterial blight. For each state and season, 20 plants were sampled from each of 7 to 12 direct-seeded crops twice in the fall or winter and three times from spring to summer; and from each of 2 to 4 steckling (root-to-seed) crops three times from spring to summer. X. campestris pv. carotae was detected in 1 of 15 and 6 of 32 stock seed lots planted in the fall in Oregon and Washington, respectively, and in 2 of 6 steckling shipments planted in each state in the spring. The pathogen was detected at 102 to 108 CFU/g foliage in 1 of 22 and 10 of 14 direct-seeded crops within 2 months of planting in 2001 and 2002, respectively. The prevalence of X. campestris pv. carotae then increased through the season in most seed crops, although bacterial blight symptoms were not observed until April in Oregon and July in Washington in both seasons. In August 2002 and 2003, X. campestris pv. carotae was detected in all 10 and 13 crops surveyed in Oregon, respectively; and in 11 of 12 and 7 of 10 crops in Washington, respectively. The pathogen was typically less prevalent in steckling versus direct-seeded crops. X. campestris pv. carotae was detected in 20 of 22 and 19 of 23 harvested seed lots in Oregon and Washington, respectively, at populations ranging from 1.3 × 101 to 1.4 × 108 CFU/g seed. Airborne X. campestris pv. carotae, detected ≤1,600 m downwind of crops being threshed in Oregon in September of 2003 and 2004, may provide a source of inoculum for newly planted seed crops between overlapping biennial seasons for carrot seed production. Despite the prevalence of this pathogen in the Pacific Northwest, carrot seed lots free of X. campestris pv. carotae were detected, demonstrating the ability to produce clean seed in this region by adhering to recommended practices for management of bacterial blight.

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The Philological Association of The Pacific Coast

PMLA ◽

10.1017/s0030812900130597 ◽

1935 ◽

Vol 50 (4) ◽

pp. 1373-1374

Keyword(s):

Annual Meeting ◽

Pacific Coast ◽

Stanford University ◽

The Pacific

The thirty-seventh annual meeting of the Philological Association of the Pacific Coast was held at Stanford University, California, on November 29 and 30, 1935.

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