APPARENT NEGATIVE GEOTROPISM IN THE DOUGLAS FIR BARK BEETLE

1942 ◽  
Vol 74 (11) ◽  
pp. 205-205 ◽  
Author(s):  
George R. Hopping
Keyword(s):  
2020 ◽  
Vol 153 (1) ◽  
pp. 62-78
Author(s):  
Darrell W. Ross

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 Previously unpublished data from two studies on novel uses of MCH are included.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.


Ecology ◽  
2013 ◽  
Vol 94 (11) ◽  
pp. 2475-2486 ◽  
Author(s):  
Brian J. Harvey ◽  
Daniel C. Donato ◽  
William H. Romme ◽  
Monica G. Turner

1971 ◽  
Vol 49 (7) ◽  
pp. 1021-1024 ◽  
Author(s):  
T. S. Sahota

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.


2020 ◽  
Vol 49 (6) ◽  
pp. 1437-1448 ◽  
Author(s):  
Gabriel G Foote ◽  
Nathaniel E Foote ◽  
Justin B Runyon ◽  
Darrell W Ross ◽  
Christopher J Fettig

Abstract The status of wild bees has received increased interest following recent estimates of large-scale declines in their abundances across the United States. However, basic information is limited regarding the factors affecting wild bee communities in temperate coniferous forest ecosystems. To assess the early responses of bees to bark beetle disturbance, we sampled the bee community of a Douglas-fir, Pseudotsuga menziesii (Mirb.), forest in western Idaho, United States during a Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins (Coleoptera: Curculionidae), outbreak beginning in summer 2016. We resampled the area in summer 2018 following reductions in forest canopy cover resulting from mortality of dominant and codominant Douglas-fir. Overall, results from rarefaction analyses indicated significant increases in bee diversity (Shannon’s H) in 2018 compared to 2016. Results from ANOVA also showed significant increases in bee abundance and diversity in 2018 compared to 2016. Poisson regression analyses revealed percent tree mortality from Douglas-fir beetle was positively correlated with increases in total bee abundance and species richness, where community response variables displayed a cubic trend with percent tree mortality. Percent reduction in canopy cover from 2016 to 2018 was also correlated with bee species richness and diversity. These findings suggest that wild bee communities may benefit from changes in forest structure following bark beetle outbreaks.


1973 ◽  
Vol 51 (6) ◽  
pp. 659-661 ◽  
Author(s):  
T. S. Sahota ◽  
A. Ibaraki

In vitro yolk deposition was studied in ovaries dissected out of Dendroctonus pseudotsugae at various times after attack on host logs, and incubated in medium containing a mixture of labeled haemolymph and ovarial proteins. These proteins were not deposited in the oocytes taken from beetles which had been on host logs for less than 48 h. Such proteins were deposited as yolk in the basal and penultimate oocytes from beetles which had been on host logs for more than 48 h; younger oocytes from the same ovaries did not exhibit yolk deposition. Presence of juvenile hormone in the incubating medium did not induce yolk deposition in oocytes not already engaged in vitellogenesis.


1993 ◽  
Vol 23 (3) ◽  
pp. 479-491 ◽  
Author(s):  
Keith S. Hadley ◽  
Thomas T. Veblen

The montane forests (i.e., below ca. 2900 m) of the Colorado Front Range have experienced repeated outbreaks of western spruce budworm (Choristoneuraoccidentalis Free.) and Douglas-fir bark beetle (Dendroctonuspseudotsugae Hopk.), both of which locally attack Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco). In this study we examine the effects of historically documented outbreaks of these insects on succession, stand structure, and radial growth of host and nonhost species in Rocky Mountain National Park. The most recent budworm (1974–1985) and bark beetle (1984–present) outbreaks resulted in the most severe and widespread disturbance of these forests since the late 1800s. Stand response to these outbreaks is primarily a function of stand structure and age characteristics of Douglas-fir prior to an outbreak. Young, vigorous postfire stands show minimal budworm defoliation, and in these stands only remnant trees from the prefire generation appear susceptible to beetle-caused mortality. Dense stands exhibit higher budworm-induced mortality, which hastens the natural thinning process and shifts dominance towards the nonhost species. The stands most severely disturbed by the combined insect agents are multistoried stands with high host densities and a wide range of stem sizes. The stand response to these disturbances include the growth release of shade-intolerant, seral species, and in some cases, a higher survivorship among midsized individuals of the host Douglas-fir. The net result of the combined insect outbreaks is the temporary slowing of the successional trend towards a steady-state Douglas-fir forest. Fire suppression, by increasing the density of suppressed Douglas-fir, has previously been shown to favor increased outbreak severity of western spruce budworm in the northern Rockies. However, in the Front Range, recent increases in outbreak severity and their synchroneity may also be the result of large areas of forest, burned during the late 19th century during European settlement, simultaneously entering structural stages susceptible to insect outbreak.


1997 ◽  
Vol 12 (2) ◽  
pp. 52-54 ◽  
Author(s):  
Darrell W. Ross ◽  
Christine G. Niwa

Abstract Pheromone baits for the Douglas-fir beetle were applied alone and in combination with the antiaggregation pheromone, 3-methylcyclohex-2-en-1-one (MCH), to test potential treatments for creating snags to improve wildlife habitat. All baited trees were attacked by beetles following both treatments. However, more unbaited trees were attacked on plots without MCH than on plots with MCH. One year after treatment, more of the attacked trees were dead on plots without MCH than on plots with MCH. Bark beetle pheromones can be used effectively to create snags for improving wildlife habitat, but to achieve specific objectives treatments must be prescribed based on knowledge of the expected beetle population densities. West. J. Appl. For. 12(2):00-00.


1961 ◽  
Vol 37 (4) ◽  
pp. 308-314 ◽  
Author(s):  
R. R. Lejeune ◽  
L. H. McMullen ◽  
M. D. Atkins

All species of bark beetles of economic importance prefer to attack freshly-killed host material. Logging slash, wind-throw, and fire-killed timber provide ideal breeding grounds for bark beetles. A few species, mostly in the Dendroctonus group, are able to attack and kill living trees. When beetles in this group, raised in preferred host material, cannot find any or enough freshly-killed trees, logs, or slash to enter, they may attack living trees. In the interior of British Columbia, infestations of the Douglas fir beetle can often be traced to logging disturbance.The regulation or control of bark beetle populations involves several generally accepted principles:(a) The removal or destruction of beetle broods in infested material in time to prevent the new adult beetles from emerging to attack fresh material.(b) Continuous logging in time and area will tend to keep the beetles in the slash.(c) Keep suitable breeding material to a minimum.(d) The use of trap trees or trap logs for remedial action in trouble areas.


1947 ◽  
Vol 79 (7-8) ◽  
pp. 150-153 ◽  
Author(s):  
George R. Hopping

In 1935, De Leon published a comprehensive paper on Medetera aldrichii as a predator ol Dendroctonus monticolae Hopk., in western white pine and lodgepole pine in Washington. The following data may prove of value because a different species of bark-beetle is involved and additional information is given. The observations were made in 1941 and 1942 at the Trinity Valley Forest Insect Field Station, 22 miles from Vernon. This locality is 2,100 feet above sea level in a mixed timber stand of western larch, Douglas fir, western red cedar, Engelmann spruce, western hemlock, and western white pine. D. pseudotsugae breeds in Douglas fir, and occasionally in western larch.


Sign in / Sign up

Export Citation Format

Share Document