scholarly journals Spatial Dispersal of Douglas-Fir Beetle Populations in Colorado and Wyoming

ISRN Forestry ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
John R. Withrow ◽  
John E. Lundquist ◽  
José F. Negrón
Keyword(s):  
Bark Beetles ◽  
Gaussian Function ◽  
Population Data ◽  
Dispersal Distance ◽  
Douglas Fir ◽  
Dendroctonus Pseudotsugae ◽  
Gis Technique ◽  
Flight Season ◽  
Dispersal Distances ◽  
Multiple Tree

Bark beetles (Coleoptera: Curculionidae: Scolytinae) are mortality agents to multiple tree species throughout North America. Understanding spatiotemporal dynamics of these insects can assist management, prediction of outbreaks, and development of “real time” assessments of forest susceptibility incorporating insect population data. Here, dispersal of Douglas-fir beetle (Dendroctonus pseudotsugae Hopk.) is estimated over four regions within Colorado and Wyoming from 1994 to 2010. Infestations mapped from aerial insect surveys are utilized as a proxy variable for Douglas-fir beetle (DFB) activity and analyzed via a novel GIS technique that co-locates infestations from adjacent years quantifying distances between them. Dispersal distances of DFB infestations were modeled with a cumulative Gaussian function and expressed as a standard dispersal distance (SDD), the distance at which 68% of infestations dispersed in a given flight season. Average values of SDD ranged from under 1 kilometer for the region of northwestern Colorado to over 2.5 kilometers for infestations in Wyoming. A statistically significant relationship was detected between SDD and infestation area in the parent year, suggesting that host depletion and density-dependent factors may influence dispersal. Findings can potentially provide insight for managers—namely, likelihood of DFB infestation increase for locations within two to five kilometers of an existing infestation.

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.

ATTACK BY GNATHOTRICHUS SULCATUS (COLEOPTERA: SCOLYTIDAE) ON STUMPS AND FELLED TREES BAITED WITH SULCATOL AND ETHANOL

1977 ◽  
Vol 109 (5) ◽  
pp. 675-686 ◽  
Author(s):  
J. A. McLean ◽  
J. H. Borden
Keyword(s):  
Bark Beetles ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Systemic Insecticide ◽  
Dendroctonus Pseudotsugae ◽  
University Of British Columbia ◽  
Steady Decrease ◽  
Population Aggregation ◽  
The University

AbstractEthanol and sulcatol (6-methyl-5-hepten-2-ol), primary attractant and population aggregation pheromone, respectively, for Gnathotrichus sulcatus, were deployed alone or in combination on stumps and felled trees in the University of British Columbia Research Forest, Maple Ridge, B.C. On 18 April 1974, four Douglas-fir trees were felled at each of three locations, and four western hemlock trees were felled at each of three other locations. Felled trees and their respective stumps were baited on 26 April. Attacks by G. sulcatus and bark beetles were recorded at weekly intervals until 25 October. G. sulcatus attacks increased rapidly, reaching a maximum in June and July, followed by a steady decrease to October. Attacks by Dendroctonus pseudotsugae, Pseudohylesinus nebulosus, and P. tsugae showed characteristic seasonal trends, but were not correlated to any of the treatments. Over half the G. sulcatus attacks were on stumps, in which attack densities reached 683.5/m2. The greatest numbers of attacks were on stumps and logs baited with sulcatol or sulcatol plus ethanol. There was a significant interaction between sulcatol and ethanol on Douglas-fir but not on western hemlock. Significantly more G. sulcatus attacked ethanol-baited western hemlock stumps and logs than unbaited controls. However, there was no difference between the level of attack on ethanol-baited Douglas-fir and the controls. The role of ethanol is hypothesized to be more of a boring stimulant than a major attractant. Stumps baited with sulcatol and then treated with ethanolic solutions of systemic insecticide could be used to trap and kill field populations, thus reducing numbers of G. sulcatus being transported to log-booming grounds, dryland sorting areas, and sawmills.

The Life History and Habits of Scolytus unispinosus Leconte (Coleoptera: Scolytidae) in the Interior of British Columbia

1962 ◽  
Vol 94 (1) ◽  
pp. 17-25 ◽  
Author(s):  
L. H. McMullen ◽  
M. D. Atkins
Keyword(s):  
British Columbia ◽  
Bark Beetles ◽  
Pacific Coast ◽  
Rocky Mountain ◽  
Economic Importance ◽  
Douglas Fir ◽  
Dendroctonus Pseudotsugae ◽  
Rocky Mountain Region ◽  
The Pacific ◽  
Standing Timber

The Douglas-fir engraver, Scolytus unispinosus Leconte, is a common bark beetle throughout the Pacific Coast and Rocky Mountain Region of North America. Although it occasionally kills young trees (Chamberlin, 1939), it is of minor economic importance, usually confining its attack to tops, limbs and logging slash. In standing timber it acts primarily as a secondary insect, attacking the tops and branches of trees killed or severely weakened by other agents. In the interior of British Columbia it is commonly found in Douglas fir, Pseudotsuga menziesii (Mirb.) Franco, and thus it is of interest as an associate of the Douglas-fir beetle, Dendroctonus pseudotsugae Hopk. Two other bark beetles Pseudohylesinus nebulosus (Leconte) and Scolytus tsugae (Swaine) with similar associations were studied earlier (Walters and McMullen, 1956; McMullen and Atkins, 1959).

On the Flight and Host Selection of the Douglas-fir Beetle, Dendroctonus pseudotsugae Hopk. (Coleoptera: Scolytidae)

1962 ◽  
Vol 94 (12) ◽  
pp. 1309-1325 ◽  
Author(s):  
L. H. McMullen ◽  
M. D. Atkins
Keyword(s):  
Experimental Data ◽  
Life Cycle ◽  
Host Selection ◽  
Bark Beetles ◽  
Time Of Flight ◽  
Field Studies ◽  
Douglas Fir ◽  
Major Portion ◽  
Dendroctonus Pseudotsugae ◽  
Selection Of

The flight of bark beetles covers a short but important period of their life cycle, during which they are exposed to conditions not encountered during the major portion of their life under the bark. The time of flight and the factors which affect it are important, not only to the dispersal and survival of the insect, but also in the interpretation of experimental data dependent upon the beetle's flight activity.Chapman (1954), Rudinsky and Vité (1956), and Atkins (1959, 1960, 1961) studied the flight of the Douglas-fir beetle under laboratory conditions, but there is scant reference to field studies on the flight of this insect. Chapman and Kinghorn (1958) recorded the number caught in window flight traps near Cowichan Lake, B.C., and unpublished reports describe emergence records obtained from cage studies conducted near Lumby, B.C.

ATTRACTION AND REPRESSION OF DENDROCTONUS PSEUDOTSUGAE (COLEOPTERA: SCOLYTIDAE) BY THREE SYNTHETIC PHEROMONES IN TRAPS IN OREGON AND IDAHO

1972 ◽  
Vol 104 (6) ◽  
pp. 815-822 ◽  
Author(s):  
J. A. Rudinsky ◽  
M. M. Furniss ◽  
L. N. Kline ◽  
R. F. Schmitz
Keyword(s):  
Bark Beetles ◽  
Douglas Fir ◽  
New Method ◽  
Host Volatiles ◽  
Dendroctonus Pseudotsugae ◽  
Sticky Traps ◽  
Comparative Tests ◽  
Host Attractants ◽  
Alpha Pinene ◽  
Made In

AbstractComparative tests were made in Oregon and Idaho employing sticky traps with three synthetic pheromones of Dendroctonus pseudotsugae Hopkins, frontalin, 3-methyl-2-cyclohexen-1-one, and trans-verbenol, and the host attractants Douglas-fir resin, alpha-pinene, and camphene. The attractiveness of frontalin combined with host volatiles reported earlier from Idaho was confirmed. The combination of trans-verbenol with frontalin plus camphene in Oregon brought the highest response among synthetic treatments, but the addition of trans-verbenol to other treatments with frontalin sometimes decreased beetle response.3-Methyl-2-cyclohexen-1-one almost nullified the attractiveness of all baits tested. The practical use of such a compound to prevent beetle aggregation and protect susceptible Douglas-fir trees as well as to regulate the "spillover" from attractive baits is considered as a possible new method of protection against bark beetles.

ABUNDANCE OF THE FIR ENGRAVER, SCOLYTUS VENTRALIS, AND THE DOUGLAS-FIR BEETLE, DENDROCTONUS PSEUDOTSUGAE, FOLLOWING TREE DEFOLIATION BY THE DOUGLAS-FIR TUSSOCK MOTH, ORGYIA PSEUDOTSUGATA

1984 ◽  
Vol 116 (3) ◽  
pp. 293-305 ◽  
Author(s):  
L. C. Wright ◽  
A. A. Berryman ◽  
B. E. Wickman
Keyword(s):  
Bark Beetles ◽  
Female Parent ◽  
Douglas Fir ◽  
Mortality Factors ◽  
Dendroctonus Pseudotsugae ◽  
Tussock Moth ◽  
Orgyia Pseudotsugata ◽  
Tree Defoliation ◽  
Key Factor ◽  
Adult Dispersal

AbstractFir engraver and Douglas-fir beetle numbers were monitored during and after an outbreak of the Douglas-fir tussock moth. The population behavior of the two species of bark beetles was similar. Number of emerged offspring/female was highest during the years of defoliation and declined afterward. Total number of beetle attacks peaked 1 to 2 years after defoliation ended and then declined. During and 1 year after defoliation, beetles generally infested trees that had greater than 90% defoliation. After this time infestations were not as strongly associated with heavily defoliated trees. Life tables were constructed for beetles within trees and for beetles per area of forest land. Key mortality factors acting on beetles within trees occurred during the larval and pupal stages. Mortality during adult dispersal was a key factor when beetle density per area of land was considered. Although beetle offspring emerging per dm2 of bark surface was relatively low in defoliated trees, defoliation appeared to reduce host resistance which enabled beetles to successfully attack at lower densities, reducing intraspecific competition, and resulting in increased emergence of offspring/female parent.

Tree size and growth history predict breeding densities of Douglas-fir beetles in fallen trees

2001 ◽  
Vol 133 (5) ◽  
pp. 697-704 ◽  
Author(s):  
M.L. Reid ◽  
S.S. Glubish
Keyword(s):  
Growth Rate ◽  
Tree Growth ◽  
Bark Beetles ◽  
Growth Increment ◽  
Douglas Fir ◽  
Dendroctonus Pseudotsugae ◽  
Dead Trees ◽  
Tree Growth Rate ◽  
Highly Correlated ◽  
Tree Characteristics

AbstractFor bark beetles (Coleoptera: Scolytidae) breeding in fallen trees, the tree characteristics that are associated with higher breeding densities are poorly known. The breeding densities of Douglas-fir beetles, Dendroctonus pseudotsugae Hopkins, in freshly felled Douglas-fir, Pseudotsugae menziesii (Mirb.) Franco, were examined with respect to tree diameter, phloem thickness, and several measures of tree growth rate over the past year to 10 years prior to tree death. Trees were felled in 8 decks of 3–12 trees to provide a range of tree qualities in a given location. Stepwise regression revealed that of the tree characteristics measured, only diameter was needed to explain the density of beetle attacks on trees within decks. Because diameter, phloem thickness, and growth-increment measures were all highly correlated, attack density also increased with phloem thickness and growth rate prior to felling when these measures were analyzed individually. The apparent preference for larger trees with thicker phloem is consistent with published results for live trees, but the positive effect of tree growth rate prior to death is contrary to results for beetles attacking live trees. Thus, assessments of stand susceptibility to bark beetles based on tree growth rate may differ depending on whether beetles are initially breeding in live or dead trees.

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.

scholarly journals Interacting effects of forest fragmentation and howler monkey foraging on germination and disperal of fig seeds

Oryx ◽  
2002 ◽  
Vol 36 (3) ◽  
pp. 266-271 ◽  
Author(s):  
Juan Carlos Serio-Silva ◽  
Victor Rico-Gray
Keyword(s):  
Dispersal Distance ◽  
Alouatta Palliata ◽  
Howler Monkey ◽  
Forest Fragment ◽  
Howler Monkeys ◽  
Conservation Policies ◽  
Dispersal Distances ◽  
Alouatta Palliata Mexicana ◽  
Fragmented Forests ◽  
Individual Trees

We studied changes in germination rates and dispersal distance of seeds of Ficus perforata and F. lundelli dispersed by howler monkeys (Alouatta palliata mexicana), in a small (40 ha) ‘disturbed’ and a larger (>600 ha) ‘preserved’ tropical rainforest in southern Veracruz, Mexico. The interaction between A. p. mexicana and Ficus (Urostigma) spp. is beneficial for the interacting species and has important implications for their conservation. Howler monkeys gain from the ingestion of an important food source, germination rates of Ficus seeds are improved by passage through the monkeys' digestive tract, and the seeds are more likely to be deposited in a site suitable for germination and development. Seed dispersal distances are relatively larger in the preserved site, with both the size of the forest area and the spatial pattern of Ficus affecting the dispersal process. In a large forest fragment with ‘regularly’ distributed Ficus individuals the howler monkeys move away from the seed source, increasing the probability that the seeds are desposited on a tree other than Ficus, which is important for the germination and future development of a hemiepiphytic species. In a small forest fragment with trees distributed in clumps howlers repeatedly use the same individual trees, and faeces containing seeds may be dropped on unsuitable trees more often. These are key issues when addressing conservation policies for fragmented forests.

scholarly journals Dispersal Kernel Determines Symmetry of Spread and Geographical Range for an Insect

2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
Jeffrey D. Holland
Keyword(s):  
Sugar Maple ◽  
Spatial Dynamics ◽  
Geographic Range ◽  
Dispersal Distance ◽  
Dispersal Kernel ◽  
Geographical Range ◽  
Spatial Distributions ◽  
Longhorned Beetle ◽  
Ecological Patterns ◽  
Dispersal Distances

The distance from a source patch that dispersing insects reach depends on the number of dispersers, or random draws from a probability density function called a dispersal kernel, and the shape of that kernel. This can cause asymmetrical dispersal between habitat patches that produce different numbers of dispersers. Spatial distributions based on these dynamics can explain several ecological patterns including megapopulations and geographic range boundaries. I hypothesized that a locally extirpated longhorned beetle, the sugar maple borer, has a new geographical range shaped primarily by probabilistic dispersal distances. I used data on occurrence from Ontario, Canada to construct a model of geographical range in Indiana, USA based on maximum dispersal distance scaled by habitat area. This model predicted the new range boundary within 500 m very accurately. This beetle may be an ideal organism for exploring spatial dynamics driven by dispersal.

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