Biology and Habits of the Douglas-fir Beetle Parasite, Coeloides brunneri Viereck (Hymenoptera: Braconidae), in Western Oregon

1962 ◽  
Vol 94 (7) ◽  
pp. 748-763 ◽  
Author(s):  
Roger B. Ryan ◽  
Julius A. Rudinsky
Keyword(s):  
Douglas Fir ◽  
Economic Damage ◽  
Detailed Knowledge ◽  
Natural Control ◽  
Dendroctonus Pseudotsugae ◽  
Control Practice ◽  
Beneficial Insects ◽  
Practice Recommendations ◽  
Control Factors ◽  
History Of

Natural control factors are normally relied on to hold destructive insects below the level of economic damage. When insect control is attempted every effort should be made to prevent injury to beneficial parasites and predators.The Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, is an important enemy of Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco. Present control practices for the Douglas-fir beetle consist of rapid cutting, transportation, and milling of infested trees so that beetles will be destroyed in the slabs before they emerge to infest other trees. During these operations, natural control agents are often inadvertently destroyed along with the beetles. Because of this fact serious beetle infestations may be unnecessarily prolonged. Detailed knowledge of the life history of the narural control agents and of the effect of logging and milling practices on the populations of beneficial parasites and predators is needed before control practice recommendations, which may be less destructive to the beneficial insects, can be set forth.

3-Methylcyclohex-2-en-1-one and the Douglas-fir beetle (Coleoptera: Curculionidae): history of successful bark beetle pheromone treatments

2020 ◽  
Vol 153 (1) ◽  
pp. 62-78
Author(s):  
Darrell W. Ross
Keyword(s):  
Bark Beetle ◽  
Douglas Fir ◽  
Future Research ◽  
Beetle Species ◽  
Successful Management ◽  
Dendroctonus Pseudotsugae ◽  
Successful Development ◽  
History Of ◽  
Antiaggregation Pheromone

AbstractThis paper reviews the literature on the identification of 3-methylcyclohex-2-en-1-one (MCH) as the antiaggregation pheromone of the Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) (Coleoptera: Curculionidae) and the development of successful management applications using the pheromone. Previously unpublished data from two studies on novel uses of MCH are included. The successful development of antiaggregation pheromone-based treatments for the Douglas-fir beetle is discussed in relation to efforts to develop similar treatments for other bark beetle species, and opportunities for future research on MCH and the Douglas-fir beetle are suggested.

Studies on the Silver-spotted Tiger Moth, Halisidota argentata Pack. (Lepidoptera: Arctiidae), in British Columbia

1958 ◽  
Vol 90 (2) ◽  
pp. 65-80 ◽  
Author(s):  
G. T. Silver
Keyword(s):  
British Columbia ◽  
Vancouver Island ◽  
Douglas Fir ◽  
River Valley ◽  
Fraser River ◽  
Natural Control ◽  
Control Factors ◽  
Single Colony ◽  
Tiger Moth ◽  
Northern Portion

The silver-spotted tiger moth, Halisidota argentata Pack., is a potentially dangerous defoliator of Douglas fir in British Columbia. Natural control factors have always prevented populations from building up to destructive proportions.The literature contains little information on this insect. Fletcher recorded the first outbreak of what was probably H. argentata in British Columbia in 1887 (2). Moths were identified as H. sobrina Stretch, but this form is now recorded only from California so it was probably H. argentata. The outbreak, probably on southern Vancouver Island, was reported as “committing great depredations on the spruces here.” Mathers found H. argentata at Chilliwack in the Fraser River Valley in 1934, but there was no report of an outbreak (4). A few larvae were collected on southern Vancouver Island from 1936 to 1952. In 1953 a considerable number of colonies were observed, and the following year the silver-spotted tiger moth was in infestation proportions. In 1955 the outbreak increased in intensity, and spread northward to the limit of its known range. A survey in the spring of 1956 failed to find a single colony south of Lantzville, and the population in the northern portion of the range was greatly reduced.

STUDIES ON THE SITKA SPRUCE WEEVIL, PISSODES SITCHENSIS, IN BRITISH COLUMBIA

1968 ◽  
Vol 100 (1) ◽  
pp. 93-110 ◽  
Author(s):  
G. T. Silver
Keyword(s):  
British Columbia ◽  
Life History ◽  
Population Level ◽  
Sitka Spruce ◽  
Natural Control ◽  
Control Factors ◽  
History Of ◽  
Repeated Applications ◽  
Heavy Mortality

AbstractThe life history of the Sitka spruce weevil, Pissodes sitchensis Hopk., is described. Adults overwinter in duff at the base of trees and emerge in April or early May. Oviposition begins in late April on leaders. The larvae hatch and mine downward, eventually girdling and killing the leader. Larvae pupate in chip cocoons under the bark. Newly developed adults start emerging in August and, prior to hibernation, feed on leaders of young trees. Adults have been observed in the field as late as December.Predators caused heavy mortality but the weevil population maintained itself and increased in some years. Parasitism was light. Natural control factors reduced the population level but were incapable of controlling a population. Satisfactory control was obtained by applying DDT and phosphamidon to leaders with a hand-sprayer early in the spring, but repeated applications would be necessary to protect a plantation through the critical years.Damage to Sitka spruce regeneration and plantations in British Columbia is severe. At present, protection of Sitka spruce plantations would require considerable expense.

SURVEY OF PATHOGENS IN THE LARGE ASPEN TORTRIX, CHORISTONEURA CONFLICTANA (LEPIDOPTERA: TORTRICIDAE), IN ONTARIO AND BRITISH COLUMBIA WITH PARTICULAR REFERENCE TO GRANULOSIS VIRUS

1982 ◽  
Vol 114 (5) ◽  
pp. 457-459 ◽  
Author(s):  
John Burke ◽  
Jean Percy
Keyword(s):  
United States ◽  
British Columbia ◽  
Tree Mortality ◽  
Eastern United States ◽  
Natural Control ◽  
Granulosis Virus ◽  
Control Factors ◽  
Principal Effect ◽  
History Of ◽  
Choristoneura Conflictana

The large aspen tortrix, Choristoneura conflictana Wlk., occurs throughout the range of trembling aspen, Populus trernuloides Michx., in Canada and the eastern United States (Baker 1972). Outbreaks of the insect occur over large areas, but these outbreaks generally collapse in 2 to 3 years. The principal effect of this pest is to reduce growth of aspen, but it causes little tree mortality (Batzer 1972). Prentice (1955) reviewed the history of outbreaks of C. conflictana in Canada from 1912 to 1953 and the natural control factors of the insect. He reported an extensive parasite complement. Dead and apparently diseased insects were examined, but the only pathogen noted was infection of overwintering larvae by the fungus, Beauveria bassiana (Bals .) Vuill.

The Life History and Habits of Chrysomela crotchi Brown (Coleoptera: Chrysomelidae) in Northwestern Ontario

1965 ◽  
Vol 97 (5) ◽  
pp. 541-549 ◽  
Author(s):  
E. P. Smereka
Keyword(s):  
Life History ◽  
Adult Stage ◽  
Egg Mass ◽  
Predator Species ◽  
Control Factors ◽  
Northwestern Ontario ◽  
History Of ◽  
Males And Females ◽  
Overwintering Mortality ◽  
Larval Parasites

AbstractThe life history of Chrysomela crotchi, a univoltine species commonly found on trembling aspen, was studied in northwestern Ontario from 1959 to 1962. The most striking feature of its life history was the longevity of adults, which were capable of overwintering two successive years. Overwintered adults became active and began feeding in late May, and oviposition occurred from early June to late July. The incubation period was approximately 10 days and the three larval instars required approximately one month for development to the adult stage.Females laid more eggs during their second season and the highest number laid was 326. The number of eggs in an egg mass averaged 37.6, and the average interval between the deposition of egg masses was 4 days. Males and females mated more than once, but only one mating was necessary for a female to produce viable eggs throughout the season. Males were capable of fertilizing more than one female and remained potent for more than one season.Parasitism was low, and only two species of larval parasites were reared. Several predator species were observed preying on the immature stages. Predation and overwintering mortality appeared to be the most important control factors.

Dendroctonus pseudotsugae. [Distribution map].

2004 ◽  
Author(s):  
Keyword(s):  
British Columbia ◽  
New Mexico ◽  
North America ◽  
Geographical Distribution ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Distribution Map ◽  
Dendroctonus Pseudotsugae ◽  
New Distribution

Abstract A new distribution map is provided for Dendroctonus pseudotsugae Hopkins Coleoptera: Scolytidae Hosts: Mainly Douglas fir (Pseudotsuga menziesii), also other Pseudotsuga spp. Information is given on the geographical distribution in NORTH AMERICA, Canada, Alberta, British Columbia, Mexico, USA, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Texas, Utah, Washington, Wyoming.

Canopy disturbances over the five-century lifetime of an old-growth Douglas-fir stand in the Pacific Northwest

2002 ◽  
Vol 32 (6) ◽  
pp. 1057-1070 ◽  
Author(s):  
Linda E Winter ◽  
Linda B Brubaker ◽  
Jerry F Franklin ◽  
Eric A Miller ◽  
Donald Q DeWitt
Keyword(s):  
Pacific Northwest ◽  
Variable Density ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Old Growth ◽  
The Pacific ◽  
History Of ◽  
Horizontal Heterogeneity ◽  
Restoration Strategies

The history of canopy disturbances over the lifetime of an old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stand in the western Cascade Range of southern Washington was reconstructed using tree-ring records of cross-dated samples from a 3.3-ha mapped plot. The reconstruction detected pulses in which many western hemlock (Tsuga heterophylla (Raf.) Sarg.) synchronously experienced abrupt and sustained increases in ringwidth, i.e., "growth-increases", and focused on medium-sized or larger ([Formula: see text]0.8 ha) events. The results show that the stand experienced at least three canopy disturbances that each thinned, but did not clear, the canopy over areas [Formula: see text]0.8 ha, occurring approximately in the late 1500s, the 1760s, and the 1930s. None of these promoted regeneration of the shade-intolerant Douglas-fir, all of which established 1500–1521. The disturbances may have promoted regeneration of western hemlock, but their strongest effect on tree dynamics was to elicit western hemlock growth-increases. Canopy disturbances are known to create patchiness, or horizontal heterogeneity, an important characteristic of old-growth forests. This reconstructed history provides one model for restoration strategies to create horizontal heterogeneity in young Douglas-fir stands, for example, by suggesting sizes of areas to thin in variable-density thinnings.

Failure of ovarian development in the Douglas-fir bark beetle, Dendroctonus pseudotsugae; an analysis of gut proteases and female-specific proteins

1971 ◽  
Vol 49 (7) ◽  
pp. 1021-1024 ◽  
Author(s):  
T. S. Sahota
Keyword(s):  
High Activity ◽  
Bark Beetle ◽  
Methyl Ether ◽  
Bark Beetles ◽  
Ovarian Development ◽  
Proteolytic Enzymes ◽  
Douglas Fir ◽  
Dendroctonus Pseudotsugae ◽  
Specific Proteins ◽  
Female Specific

The failure of ovarian development in Douglas-fir bark beetles denied of their natural gallery environment and maintained on host bark chips was investigated. Such insects possessed a high activity of proteolytic enzymes in their guts but relatively small amounts of female-specific proteins both in haemolymph and the oocytes. Topical application of farnesyl methyl ether did not increase the activity of gut proteases but resulted in increased amounts of female-specific proteins in haemolymph and ovaries. Thus it appears that the Douglas-fir bark beetles maintained on bark chips do not suffer from an inability to break down the ingested proteins, but synthesize and transfer less than normal amounts of female-specific proteins to the developing oocytes.

scholarly journals Causes and consequences of the sinkhole at El Trébol of Quito, Ecuador – implications for economic damage and risk assessment

2016 ◽  
Vol 16 (9) ◽  
pp. 2031-2041 ◽  
Author(s):  
Theofilos Toulkeridis ◽  
Fabián Rodríguez ◽  
Nelson Arias Jiménez ◽  
Débora Simón Baile ◽  
Rodolfo Salazar Martínez ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Indirect Costs ◽  
Capital City ◽  
Fear Of Recurrence ◽  
Economic Damage ◽  
State Of Emergency ◽  
The North ◽  
Hydrogeological Characteristics ◽  
History Of ◽  
The City

Abstract. The so-called El Trébol is a critical road interchange in Quito connecting the north and south regions of the city. In addition, it connects Quito with the highly populated Los Chillos Valley, one of the most traveled zones in the Ecuadorian capital. El Trébol was constructed in the late 1960s in order to resolve the traffic jams of the capital city and for that purpose the Machángara River was rerouted through an underground concrete box tunnel. In March 2008, the tunnel contained a high amount of discarded furniture that had been impacting the top portion of the tunnel, compromising the structural integrity. On 31 March 2008 after a heavy rainfall a sinkhole of great proportions formed in the Trébol traffic hub. In the first few minutes, the sinkhole reached an initial diameter of 30 m. The collapse continued to grow in the following days until the final dimensions of 120 m in diameter and some 40 m of depth, revealing the Machángara River at the base of the sinkhole.A state of emergency was declared. The cause of the sinkhole was a result of the lack of monitoring of the older subterranean infrastructure where trash had accumulated and damaged the concrete tunnel that channelized the Machángara River until it was worn away for a length of some 20 m, leaving behind the sinkhole and the fear of recurrence in populated areas.With the intent to understand the causes and consequences of this sinkhole event, rainfall data are shown together with hydrogeological characteristics and a view back to the recent history of sinkhole lineation or arrangement of the city of Quito. The economic impact is also emphasized, where the direct costs of the damage and the reconstruction are presented and compared to indirect costs associated with this socio-natural disaster. These analyses suggest that the costs of indirect financial damage, like time loss or delay, and subsequent higher expenses for different types of vehicles, are equivalent to many times the costs of the reconstruction of El Trébol.

scholarly journals High biogeographic and latitudinal variability in gastropod drilling predation on molluscs along the eastern Indian coast: Implications on the history of fossil record of drillholes

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256685
Author(s):  
Subhronil Mondal ◽  
Hindolita Chakraborty ◽  
Sandip Saha ◽  
Sahana Dey ◽  
Deepjay Sarkar
Keyword(s):  
Spatial Variability ◽  
Large Scale ◽  
Abiotic Factors ◽  
Eastern Coast ◽  
Detailed Knowledge ◽  
Biogeographic Pattern ◽  
Drilling Predation ◽  
History Of ◽  
Latitudinal Patterns ◽  
Consecutive Time

Studies on the large-scale latitudinal patterns of gastropod drilling predation reveal that predation pressure may decrease or increase with increasing latitude, or even show no trend, questioning the generality of any large-scale latitudinal or biogeographic pattern. Here, we analyze the nature of spatio-environmental and latitudinal variation in gastropod drilling along the Indian eastern coast by using 76 samples collected from 39 locations, covering ~2500 km, incorporating several ecoregions, and ~15° latitudinal extents. We find no environmental or latitudinal gradient. In fact, drilling intensity varies highly within the same latitudinal bin, or oceanic sub-basins, or even the same ecoregions. Moreover, different ecoregions with their distinctive biotic and abiotic environmental variables show similar predation intensities. However, one pattern is prevalent: some small infaunal prey taxa, living in the sandy-muddy substrate—which are preferred by the naticid gastropods—are always attacked more frequently over others, indicating taxon and size selectivity by the predators. The result suggests that the biotic and abiotic factors, known to influence drilling predation, determine only the local predation pattern. In the present case, the nature of substrate and prey composition determines the local predation intensity: soft substrate habitats host dominantly small, infaunal prey. Since the degree of spatial variability in drilling intensity within any time bin can be extremely high, sometimes greater than the variability across consecutive time bins, temporal patterns in drilling predation can never be interpreted without having detailed knowledge of the nature of this spatial variability within a time bin.

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