Life History and Habits of a Midge, Contarinia washingtonensis Johnson (Diptera: Cecidomyiidae), in Douglas-fir Cones

1963 ◽  
Vol 95 (11) ◽  
pp. 1168-1175 ◽  
Author(s):  
Alan F. Hedlin ◽  
Norman E. Johnson
Keyword(s):  
British Columbia ◽  
Life History ◽  
Late Summer ◽  
Douglas Fir ◽  
Direct Damage ◽  
Seed Loss

AbstractThe midge Contarinia washnigtonensis Johnson is capable of causing serious seed loss in Douglas-fir in British Columbia, Washington and Oregon. The female lays its eggs from late May until early July in the young cones. When the eggs hatch larvae feed in the cone scales, sometimes causing direct damage to seeds and often killing scales before cone maturity. When larvae have completed feeding they leave the cone scales in late summer and autumn to drop to the ground where they spin cocoons and remain overwinter in the litter.

On the Life History of the Douglas-fir Cone Moth, Barbara colfaxiana (Kft.) (Lepidoptera: Olethreutidae), and one of its Parasites, Glypta evetriae Cush. (Hymenoptera: Ichneumonidae)

1960 ◽  
Vol 92 (11) ◽  
pp. 826-834 ◽  
Author(s):  
A. F. Hedlin
Keyword(s):  
British Columbia ◽  
Life History ◽  
Rocky Mountains ◽  
Pacific Coast ◽  
Douglas Fir ◽  
Lake Area ◽  
Seed Loss ◽  
The Pacific ◽  
History Of ◽  
Loss Range

The Douglas-fir cone moth has been reported causing damage to cones and seeds of Douglas fir for a number of years; reports of seed loss range from light to almost 100 per cent. The insect occurs throughout the range of the host in British Columbia, the Pacific Coast States, and the Rocky Mountains.Observations recorded here were made during 1957 and 1958 in the Cowichan Lake area of Vancouver Island, and 1959 in the interior of British Columbia.

Potential for pheromone-baited traps to predict seed loss caused by Contarinia oregonensis (Diptera: Cecidomyiidae)

2002 ◽  
Vol 134 (5) ◽  
pp. 689-697 ◽  
Author(s):  
P. Morewood ◽  
W.D. Morewood ◽  
R.G. Bennett ◽  
G. Gries
Keyword(s):  
United States ◽  
Pseudotsuga Menziesii ◽  
Late Summer ◽  
Early Spring ◽  
Douglas Fir ◽  
Washington State ◽  
Gall Midges ◽  
Seed Loss ◽  
Baited Traps ◽  
Positive Correlations

AbstractIn seed orchards of Douglas-fir, Pseudotsuga menziesii (Mirbel) Franco (Pinaceae), located in Washington State and Oregon, United States, we tested whether catches of male Douglas-fir cone gall midges, Contarinia oregonensis Foote, in pheromone-baited traps can be used to predict the extent of galled scales (= seed loss at harvest) caused by developing larvae. In 2000, 27 experimental blocks (4–7 ha each) were selected. In each block we recorded mean numbers of (i) male C. oregonensis captured in 20 pheromone-baited Wing traps, (ii) egg-infested scales in up to 50 conelets in early spring, and (iii) galled scales in up to 50 cones in late summer. In 2001, the experiment was repeated with 20 Delta traps in each of 26 experimental blocks. Moreover, catches of C. oregonensis and nontarget insects in Delta traps and Wing traps were compared in one additional orchard block in 2001. In both years there were positive correlations between mean numbers of egg-infested and galled scales and between mean numbers of captured male C. oregonensis and mean numbers of both egg-infested and galled scales, particularly when only experimental blocks with ≥50% of trees bearing at least 5 conelets were considered. Our results suggest that 4 or 2 captured male C. oregonensis in Wing or Delta traps, respectively, warrant insecticidal control of C. oregonensis. Delta traps, which captured fewer nontarget insects, would be more suitable than Wing traps for operational implementation of this technology.

A LEAF BLIGHT OF POPULUS TACAMAHACA MILL. CAUSED BY AN UNDESCRIBED SPECIES OF LINOSPORA

1939 ◽  
Vol 17c (7) ◽  
pp. 232-238
Author(s):  
G. E. Thompson
Keyword(s):  
British Columbia ◽  
Life History ◽  
Mycelial Growth ◽  
Late Summer ◽  
Leaf Blight ◽  
Potato Dextrose Agar ◽  
Infected Leaf ◽  
Undescribed Species ◽  
Leaf Tissues ◽  
Conidial Stage

A foliage disease of Populus tacamahaca Mill., caused by a fungus that has been given the name Linospora tetraspora n. sp., is known to occur in Alberta British Columbia, Ontario, and Quebec, Canada. The lesions on the leaves are of various sizes, dark brown in colour, with very irregular and diffused margins. The leaves may be completely invaded, discoloured, and dropped prematurely. Small, black, circular or irregular pseudoclypei develop on the upper surface of the infected leaves. No true conidial stage was found in the life history. Spermatia are produced in acervuli that develop in the cells of the upper epidermis during late summer and autumn. Isolations from ascospores and plantings of infected leaf tissues gave similar mycelial growth on potato dextrose agar. The pathogenicity of the fungus was demonstrated by the inoculation of healthy leaves with a suspension of ascospores. Symptoms typical of the disease developed in about a month. The fungus was re-isolated from the inoculated leaves.

A NEW SPECIES OF CAMPTOMYIA (DIPTERA: CECIDOMYIIDAE) FROM DOUGLAS-FIR CONES

1968 ◽  
Vol 100 (5) ◽  
pp. 532-535
Author(s):  
Alan F. Hedlin ◽  
Norman E. Johnson
Keyword(s):  
British Columbia ◽  
Life History ◽  
New Species ◽  
Douglas Fir ◽  
A New Species

AbstractCamptomyia pseudotsugae, a new species of midge in Douglas-fir cones from Washington and British Columbia, is described. Notes on its life history and habits in relation to those of its cohabitant Contarinia washingtonensis Johnson are included.

DERMEA PSEUDOTSUGAE N. SP., A CAUSAL AGENT OF PHLOEM NECROSIS IN DOUGLAS FIR

1967 ◽  
Vol 45 (10) ◽  
pp. 1803-1809 ◽  
Author(s):  
A. Funk
Keyword(s):  
British Columbia ◽  
Life History ◽  
New Species ◽  
Douglas Fir ◽  
Causal Agent ◽  
Cultural Characteristics ◽  
Phloem Necrosis ◽  
A New Species ◽  
Extensive Damage

A new species of Dermea is described. The fungus was associated with extensive damage to young Douglas fir (P seudotsuga menziesii) following severe early frosts in the Cariboo Region of British Columbia. Inoculation tests proved the fungus was capable of invading bark wounds and causing necrosis. Life history and cultural characteristics of the fungus are presented. The development of the disease is described and discussed.

Life History and Habits of a Midge, Phytophaga thujae Hedlin (Diptera: Cecidomyiidae) in Western Red Cedar Cones

1964 ◽  
Vol 96 (7) ◽  
pp. 950-957 ◽  
Author(s):  
A. F. Hedlin
Keyword(s):  
British Columbia ◽  
Life History ◽  
Larval Stage ◽  
Late Summer ◽  
Vancouver Island ◽  
Thuja Plicata ◽  
Mortality Factors ◽  
Pupal Development ◽  
Red Cedar ◽  
Western Red Cedar

AbstractThe midge, Phytophaga thujae Hedlin, is a common pest in cones of western red cedar, Thuja plicata Donn. In some years nearly 100% of cones in localities on Vancouver Island, British Columbia, are infested.Adults emerge in March and April to oviposit on young cones. Eggs hatch during April and May. Larvae feed on seeds and scales, and in late summer spin cocoons in the cones, in which to overwinter. Prepupal and pupal development occur during winter.Mortality factors include parasites and competition. Species of Torymus and Tetrastichus parasitize larvae of the midge. In years of severe infestation, competition in early stages can cause considerable mortality.A portion of the population may remain in diapause in the larval stage each year.

Life-History and Habits of Scolytus tsugae (Swaine) (Coleoptera: Scolytidae) in the Interior of British Columbia

1959 ◽  
Vol 91 (7) ◽  
pp. 416-426 ◽  
Author(s):  
L. H. McMullen ◽  
M. D. Atkins
Keyword(s):  
British Columbia ◽  
Life History ◽  
Pacific Coast ◽  
Rocky Mountain ◽  
Economic Importance ◽  
Douglas Fir ◽  
Dendroctonus Pseudotsugae ◽  
Small Areas ◽  
Rocky Mountain Region ◽  
The Pacific

Scolytus tsugae (Swaine) is a bark beetle that occurs throughout the Pacific Coast and Rocky Mountain Region and is common in the interior of British Columbia. Although Bedard (1938) reported that it had killed small areas of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) reproduction, it is of minor economic importance and usually confines its attack to tops, limbs, and logging slash. A knowledge of the life-history and habits of this insect is desirable for an understanding of the effects of interspecific competition on the development of the Douglas-fir beetle, Dendroctonus pseudotsugae Hopk., with which it is often associated in Douglas fir.

Cylindrocarpon and Fusarium root colonization of Douglas-fir seedlings from British Columbia reforestation sites

1998 ◽  
Vol 28 (8) ◽  
pp. 1198-1206 ◽  
Author(s):  
Paige E Axelrood ◽  
William K Chapman ◽  
Keith A Seifert ◽  
David B Trotter ◽  
Gwen Shrimpton
Keyword(s):  
British Columbia ◽  
Pseudotsuga Menziesii ◽  
Root Colonization ◽  
Linear Trend ◽  
Poor Performance ◽  
Douglas Fir ◽  
Root Infection ◽  
Significant Linear Trend ◽  
Conifer Seedlings ◽  
Cylindrocarpon Destructans

Poor performance of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantations established in 1987 has occurred in southwestern British Columbia. Affected sites were planted with 1-year-old container stock that exhibited some root dieback in the nursery. A study was initiated in 1991 to assess Cylindrocarpon and Fusarium root infection in planted and naturally regenerating (natural) Douglas-fir seedlings from seven affected plantations. Percentages of seedlings harboring Cylindrocarpon spp.and percent root colonization were significantly greater for planted seedlings compared with natural seedlings. A significant linear trend in Cylindrocarpon root colonization was observed for planted seedlings with colonization levels being highest for roots closest to the remnants of the root plug and decreasing at distances greater than 10cm from that region. This trend in Cylindrocarpon colonization was not observed for natural seedlings. Cylindrocarpon destructans (Zins.) Scholten var. destructans and C.cylindroides Wollenw. var. cylindroides were the only species isolated from planted and natural conifer seedlings. For most sites, percentage of seedlings harboring Fusarium spp.and percent Fusarium root colonization were less than for Cylindrocarpon. Recovery of Fusarium spp.from seedlings and root colonization levels were not significantly different for planted and natural seedlings from all sites.

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