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Bioinspired smell sensor to trace pheromone released by the European spruce bark beetleCederquist, Isac January 2020 (has links)
Forests have as a of late become increasingly plagued with bark beetle infestations as a result of climate change. The damage caused by tree killing bark beetles has within recent years seen a substantial increase. Detecting and removing infested trees at an early stage is an essential part of mitigating the spread of and the damage caused by the beetle. Today, the most common way of early detection is visual detection by forestry personnel. However, this is time consuming with highly variable results. In this thesis a novel approach to tracing the European spruce bark beetle through pheromone detection is investigated. With this approach, the antennae of the beetle were paired with an epitaxial graphene chip in order to create a bioinspired smell sensor. Tests were conducted on the sensor in order to investigate how the resistance changed over the chip as a result of the sensor being exposed to the pheromone 2-methyl-3-buten-2-ol. As a result of the tests, a corelation between exposing the sensor to pheromone and an increase of the resistance over the graphene chip was noted. However, more tests need to be conducted in order to draw any definite conclusions about the efficacy of the sensor in its current form. Additionally there are opportunities to investigate further optimization alternatives regarding the design of the sensor.
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Physiological, ecological and environmental factors that predispose trees, stands and landscapes to infestation by tree-killing Dendroctonus beetlesGoodsman, Devin W. Unknown Date
No description available.
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Ekonomické vyhodnocení škod kůrovcem na lesních porostech v revíru Stříbrné Hutě / Economic evaluation of damages caused by bark beetle on forest stand in the district of Stribrne HuteHEJNÁ, Jana January 2012 (has links)
The aim of the thesis was to evaluate the damage caused by bark beetle on forest stand in the district of Stribne Hute which is managed by Forest Management Tabor. Forest stands are being damaged by various harmful effects which reduce theirs ecological stability. The damage is defined as a reduction of utility value or as a damage caused by adverse effects. Spruce bark beetle (Ips typographus L.) is significant part of entomocenosis and it is being considered as the most serious pest of spruce stands. Data from 2007 - 2012 were processed, it consisted of bark beetle matter production records, evaluation of timber harvest (especially random harvest) and calculation of revenues. The price lists of average values of spruce logs KH and A/B quality was used to calculate revenues from bark beetle matter and standard quality. The comparison of revenues was used to determinate the loss caused by bark beetle. Losses were minimal due to the quantity of bark beetle which did not reach state of emergency.
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The light at the end of the tunnel: photosensitivity in developing mountain pine beetle (Dendroctonus ponderosae)Wertman, Debra 11 December 2017 (has links)
This research explores the capacity for functional photoreception in larvae of the
mountain pine beetle (Dendroctonus ponderosae), an extremely important forest pest
insect that is well adapted for development beneath the bark of pine trees. Phototaxis
tests, gene expression analysis and development experiments were integrated to assess
mountain pine beetle larvae for light sensitivity. When presented with a phototaxis
choice test, larvae preferred dark over light microhabitats, revealing that larvae sense and
respond behaviourally to light. Long wavelength opsin transcription was identified in all
life stages, including eggs and larvae, suggesting that D. ponderosae possesses
extraretinal photosensitive capabilities across its life cycle. The long wavelength opsin
could function in phototaxis or the development phenology of immature beetles, while
the ultraviolet opsin, only found to be expressed in pupae and adults, is likely to function
in dispersal via the compound eyes. Results from two development experiments reveal
an effect of photoperiod treatment on beetle development rate when reared from the egg
stage, but not when reared from mature larvae, indicating that a critical photosensitive
life stage(s) must occur in D. ponderosae prior to the third larval instar. An effect of
photoperiod on adult emergence rates, however, appears to be independent of larval
rearing conditions. The discovery of opsin expression and negative phototaxis in eyeless
mountain pine beetle larvae, in addition to an effect of photoperiod on immature
development and adult emergence rates, suggest that light and photoperiodism likely
function in survival and life cycle coordination in this species. / Graduate / 2018-10-17
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Effect of sanitation on responses of Tribolium castaneum (herbst) (Coleoptera: tenebrionidae) life stages to structural heat treatmentsBrijwani, Monika January 1900 (has links)
Master of Science / Department of Grain Science and Industry / Subramanyam Bhadriraju / Heat treatment involves raising the ambient temperature of food-processing facilities such as flour mills to 50-60oC for killing stored-product insects. However, very little is known about the influence of sanitation on responses of stored-product insects to structural heat treatments. The impact of sanitation on responses of life stages of the red flour beetle, Tribolium castaneum, an economically important pest in flour mills, were investigated during three 24 h structural heat treatments of the Kansas State University pilot flour mill. Two sanitation levels, dusting of wheat flour (~0.5 g) and 2-cm deep flour (~43 g), were created in 25 plastic bioassay boxes each holding 50 eggs, 50 young larvae, 50 old larvae, 50 pupae, and 50 adults of T. castaneum in separate compartments. Five boxes were placed on each of five floors of the pilot mill during 13-14 May 2009, 25-26 August 2009, and 7-8 May 2010 heat treatments using forced air gas heaters. During the August 2009 and May 2010 heat treatments, 100 eggs or 100 adults of T. castaneum were exposed inside each 20 cm diameter by 15 cm high PVC ring placed only on first and third floors and holding 0.1 (15 g), 0.2 (38 g), 1 (109 g), 3 (388 g), 6 (937 g), or 10 (1645 g) cm deep wheat flour. Among the mill floors, first floor had lower maximum temperature. The first floor rests on a thick concrete foundation, did not get heated from both sides unlike other floors, and had poor air movement resulting in cold pockets (temperatures <50oC). Mortality of life stages was lower on first floor than other floors and adults were less susceptible than other life stages especially on first floor. In general, both these tests have shown that the mortality of T. castaneum life stages were influenced by how quickly temperatures reached 50oC, how long temperatures were held above 50oC, and the maximum temperature. Protective effects of sanitation were evident only if temperatures did not reach 50oC. However, removal of flour accumulations is essential to improve heat treatment effectiveness against all T. castaneum life stages during a 24 h treatment.
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Heat treatment of grain-processing facilities: gauging effectiveness against select life stages of Tribolium castaneum (Herbst) using bioassays and a thermal death kinetic modelBingham, Aaron C. January 1900 (has links)
Master of Science / Department of Grain Science and Industry / Subramanyam Bhadriraju / During heat treatment, the ambient temperature of grain-processing facilities is raised to 50-60°C for at least 24 hours to manage stored-product insects. Young larvae (first instars) of the red flour beetle, Tribolium castaneum (Herbst), are the most heat tolerant stage at 50-60°C. A thermal death kinetic (TDK) model predicted survival of T. castaneum young larvae exposed to six constant elevated temperatures between 42 and 60ºC. The model is based on logarithmic survival of T. castaneum as a function of time and logarithmic reduction in larval survival as a function of temperature. The model was validated with 12 independent temperature datasets collected during heat treatments of pilot-scale and commercial grain-processing facilities. Young larval survival in plastic boxes/vials with flour was used to validate model predictions. The heating rate to 50°C from the ambient among the 12 datasets ranged from 0.9-7.8°C/h. Mean absolute deviations between observed and predicted larval survival for 10 of the 12 datasets ranged from 2.1-11.4%; it was 16.2 and 18.3% for two other datasets. The TDK model can be used to predict survival of young larvae of T. castaneum based on time-dependent temperature profile obtained at any given location during heat treatment of grain-processing facilities.
In three commercial grain-processing facilities heat treatments were conducted for 24-27.7 hours using forced-air gas heaters. Temperatures attained and survival of 20 eggs, 20 young larvae, and 20 adults of T. castaneum in bioassay vials at various locations were determined. Across all three facilities, 5 out of 2720 adults in 136 vials, 1 out of 960 young larvae in 48 vials, and 0 out of 1760 eggs in 88 vials were alive at the end of the heat treatment. In each facility, the time in hours for 1% predicted survival of T. castaneum young larvae was positively related to how quickly temperatures reached 50°C, and negatively related to rate of heating to 50°C from the ambient, time above 50°C in hours, and the maximum temperature. Bioassays with T. castaneum life stages and the TDK model can be used to gauge effectiveness of facility heat treatments.
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Insects, Diseases and Abiotic Disorders in Southwest Forests and WoodlandsDeGomez, Tom, Garfin, Gregg 11 1900 (has links)
Revised; Originally published: 2006 / 5 pp. / Recent events in the forests of the Southwest, and across western North America, have prompted scientists to consider the role of climate variability in insect and disease cycles. Studies focusing on Arizona and other southwestern states point to multiple, interacting climate-related mechanisms that increase the propensity for forest mortality. Effects of insects on forests are complex, and species and site dependent. Many influences, such as drought, decreased precipitation, increased temperature, increased vapor pressure deficit, and increased stand density, combined in nonlinear and overlapping ways to create the recent and devastating pine bark beetle outbreaks in Arizona forests. Climate clearly plays a role in many, but not all, Southwest insect cycles. It is important that educators demonstrate the complexity of all of the interplaying issues, in order to communicate no false impressions of an “easy” or “one-size- fits-all” solution” for land managers.
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Common Insect Contaminants Found in Arizona LettuceKerns, David L. 02 1900 (has links)
2 pp. / This publication describes the common insects found in Arizona lettuce through the use of pictures. The insects include; lepidopterous larva, striped flea beetle, leafminer fly, leafminer mine, adult western flower thrips, winged adult aphid, false chinch bug, lygus bug, potato leafhopper, and threecornered alfalfa hopper.
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Guidelines for Thinning Ponderosa Pine for Improved Forest Health and Fire PreventionDeGomez, Tom 03 1900 (has links)
7 pp. / Preventing catastrophic stand replacing events are best accomplished through thinning. Lower tree densities result in greater tree growth. Stands with lower tree densities have greater plant diversity. Determining stand conditions will provide a baseline for formulating a plan to improve stand conditions. Thinning around individual trees can improve individual tree health reducing the likelihood of damage from bark beetles, fire or drought.
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Insects, Diseases, and Abiotic Disorders in Southwest Forests and Woodlands (Climate Change and Variability in Southwest Ecosystems Series)DeGomez, Tom, Garfin, Gregg 08 1900 (has links)
4 pp. / This is part of a series on climate variability and forested ecosystems / Recent events in the forests of the Southwest have prompted scientists to consider the role of climate variability in insect and disease cycles. Over 70 million pine trees along with millions of other conifers died in 2002-03. Average temperature increases of 3°C enabled the MPB at those high elevations to achieve univoltine (having one generation per year) reproduction leading to previously unheard of outbreaks in white bark pine at high elevation sites in Idaho.Aspen defoliation in Arizona and New Mexico averaged ~ 20,375 acres from 1990 to 1997. A series of events has contributed to the decline of aspen since 1997.
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