Warm Weather Research Articles

Use of Insect Exclusion Row Cover and Reflective Silver Plastic Mulching to Manage Whitefly in Zucchini Production.

The challenges that sweet potato whitefly (Bemisia tabaci) creates for vegetable production have increased in the southeastern U.S. Growers must use intensive insecticide spray programs to suppress extremely high populations during the fall growing season. Thus, the objective of this study was to evaluate the use of a reflective plastic mulch and an insect row cover as alternative methods to the current grower practices to manage whiteflies in zucchini (Cucurbita pepo) production. Field experiments were conducted with a two-level factorial experimental design of cover and plastic mulch treatments arranged in a randomized complete block design, with four replications in Georgia in 2020 and 2021, and in Alabama in 2021. Cover treatments consisted of an insect row cover installed on zucchini beds at transplanting and removed at flowering and a no-cover treatment, while plastic mulch treatments consisted of reflective silver plastic mulching and white plastic mulching. During all growing seasons, weather conditions were monitored, whitefly populations were sampled weekly, zucchini biomass accumulation was measured at five stages of crop development, and fruit yield was determined at harvesting. Warm and dry weather conditions early in the growing season resulted in increased whitefly populations, regardless of location and year. In general, the reflective silver plastic mulching reduced whitefly populations compared to the conventional white plastic by 87% in Georgia in 2020, 33% in Georgia in 2021, and 30% in Alabama in 2021. The insect row cover treatment reduced whitefly populations to zero until its removal. Consequently, zucchini plants grown with the insect row cover and reflective silver plastic mulching had an increased rate of biomass accumulation due to the lower insect pressure in all locations. Zucchini grown using silver reflective plastic mulch and row covers had an overall increase of 17% and 14% in total yield compared to white plastic mulch and no-cover treatments, respectively. Significant differences in yield among locations were likely due to severe whitefly pressure early in the fall season, and total yields in Georgia in 2020 (11,451 kg ha-1) were 25% lower than in Georgia in 2021 (15,177 kg ha-1) and in Alabama in 2021 (15,248 kg ha-1). In conclusion, silver plastic mulching and row covers reduced the whitefly population and increased biomass accumulation and total yield. These treatments can be considered ready-to-use integrated pest management practices for growers.

Exploratory comparison of flower visiting behavior and pollination ability of mason bees, bumble bees, and honey bees.

This study explored the flower visiting behaviors and pollination abilities of mason bees (Osmia excavata Alfken (Hymenoptera: Megachilidae)), bumble bees (Bombus terrestris (Linnaeus, 1758) (Hymenoptera: Apidae)), and Italian honey bees (Apis mellifera ligustica Spinola (Hymenoptera: Apidae)) in apple orchards in early spring in Jinan (located in the central region of Shandong) and Yantai (located in the Peninsula of Shandong). We compared the pollen collection patterns, flower visiting behavior, flying speed, and effects on apple pollination of the 3 types of bees. The frequencies of flower visits were significantly higher for mason bees (12.89/min in Jinan and 10.63/min in Yantai) than bumble bees and Italian honey bees in the 2 regions. The single flower residence times were significantly higher for Italian honey bees (8.22 s in Jinan and 9.43 s in Yantai), but Italian honey bees were most affected by the climate. The 3 bees differed significantly in terms of the amount of apple pollen collected and their effects on the fruit setting rate in apples (mason bees > bumble bees > Italian honey bees). The results showed that the mason bee was the most suitable pollinating species for spring apple orchards; Bumble bees were more suitable as alternative pollinators during cloudy and low temperatures; Italian honey bees were able to take advantage of their large number of worker bees in sunny and warm weather. Compared to individual bee species, a combination of 2 or 3 species of bees might be more advantageous in dealing with complex and variable weather conditions.

A Randomised Control Trial on Shigrupatra Arka Ashchyotana in Kaphaja Abhishyanda

Eyes are the most essential and delicate organ of the human body and they need special care. Vernal Keratoconjunctivitis (VKC) is recurrent, bilateral, interstitial, self-limiting allergic inflammation of the conjunctiva having periodic seasonal incidence, also known as Warm weather conjunctivitis or Spring Catarrh. Vernal Keratoconjunctivitis (VKC) is an allergic eye disease that especially affects young boys. Aim: To study the role and efficacy of Shigrupatra Arka Ashchyotana in Kaphaja Abhishyanda. Objectives: 1. To compare the efficacy between Shigrupatra Arka Ashchyotana and olopatadine eye drop (0.1%). 2. To establish a relation between Kaphaja Abhishyanda and Vernal Kerato-Conjunctivitis (VKC). Material and Methods: 40 patients of Kaphaja Abhishyanda were randomly assigned to two groups for a clinical trial. Result: The clinical data shows that the effect of therapy on Kaphaja Abhishyanda is 73.36% in Group A and 71.79% in Group B. Conclusion: It can be concluded that clinically Shigru Patra arka Aschyotana is effective in managing the symptoms of Kaphaja Abhishyanda.

Niepewność pomiarów średniej temperatury promieniowania za pomocą termometrów kulistych = Uncertainty of mean radiant-temperature measurements using globe thermometers

In the analysis of the human heat balance, the biggest problem is to precisely determine the amount of energy absorbed by a human organism under dynamically changing solar conditions and while being surrounded by many different surfaces that can absorb, emit or reflect solar radiation in different ways. Therefore, in thermal comfort studies some simplifications of the radiation field around human body are necessary and thus the concept of mean radiant temperature (Mrt) is most often used. Mrt values can be derived either from direct instrumental measurements or calculated by one of the microclimate models. The most accurate way to determine the Tmrt outdoors is by integral radiation measurements and the calculation of angular factors (i.e. the proportion of radiation received by the human body from different directions). This method involves simultaneous measurements of long- and short-wave radiation flux densities in six directions, which requires three sets of net radiometers. Although this method of Mrt determination describes the radiation environment accurately and independently of the variable wind field, it requires the use of expensive and complex measurement devices. Cheap and easy to operate alternative offers globe thermometer. In steady state conditions, readings from the air temperature sensor inside the globe thermometer (tg) will reflect the convective and radiative heat exchange around the globe thermometer. Knowing tg, as well as globe emissivity and diameter, the Mrt may be calculated. In this research three different globe thermometers were used to determine Mrt: 15-cm standard globe thermometer (SGT) and two 4-cm custom made acrylic globe thermometers (AGT) painted in black and grey. The measurements were conducted in the summer in Warsaw, on two selected green areas, under sunny and warm weather conditions. In each location Mrt measurements were taken in two spots – in the shade of trees and in the open grassy spaces, with high SVF. Our results demonstrate, that globe thermometers, although being relatively cheap and less complex instruments for determining Mrt, can be used to a limited extend, due to high instability of their indications under significant radiative loads.

Enhancing the Efficiency and Reliability of a Standalone Solar Energy System for Homes in Iraq

This study explores the knowledge regarding unconnected solar energy systems, their configurations, and the effects of Iraq's warm weather. Furthermore, it investigates the advantages and disadvantages of implementing such systems in Iraq. The research recognizes the efficacy of off-grid solar energy systems and their potential to provide clean electrical energy to meet the needs of Iraqi citizens while reducing harmful environmental emissions. The study employs an applied research project to assess the operational efficiency of off-grid solutions. The PVSYST application was used to simulate the solar energy system data. The research aims to develop off-grid solar energy systems, assess the suitability of building roofs, examine how heat affects panel productivity, and evaluate the impact of shading on energy levels, among other objectives. The study also covers the components of solar energy systems and how to assess their quality to withstand Iraq's typically hot climate.

Modelling of a hybrid wind power generator–water distillation system using a Venturi tunnel

Abstract This study presents the development of a novel hybrid wind power generator–water distillation system with the objective of providing sustainable solutions for impoverished isolated communities facing limited resources. The advantage of the proposed system is its ability to operate day and night; therefore, it produces larger quantities of distilled water even on cloudy days with winds. The system comprises a Venturi tunnel integrated with a wind turbine, an attached impure water tank, and a condenser located at the end section. The accelerated airflow at the throat section serves two purposes: water evaporation from the tank and power generation through the wind turbine. The evaporated water is subsequently collected as the airflow decelerates and the pressure decreases along the diverging section. Theoretical and computational modelling is employed to design the system by examining air speed, area ratio, relative humidity, as well as air, and water temperatures. The system exhibits enhanced performance under warm and dry weather conditions, thereby optimizing its performance. Conversely, temperature and relative humidity do not affect power generation; it was increased by higher air speeds and larger area ratios. This data-driven approach ensures optimal design parameters are selected, aligning the system's capabilities with the specific freshwater demand.

Hot summers raise public awareness of toxic cyanobacterial blooms

Water quality of eutrophic lakes is threatened by harmful cyanobacterial blooms, which are favored by summer heatwaves and expected to intensify with global warming. Societal demands on surface water for drinking, irrigation and recreation are also highest in summer, especially during dry and warm conditions. Here, we analyzed trends in online searches to investigate how public awareness of cyanobacterial blooms is impacted by temperature in nine different countries over almost twenty years. Our findings reveal large seasonal and interannual variation, with more online searches for harmful cyanobacteria in temperate regions during hot summers. Online searches and media attention increased even more steeply with temperature than the incidence of cyanobacterial blooms, presumably because lakes attract more people during warm weather. Overall, our study indicates that warmer summers not only increase cyanobacterial bloom incidence, but also lead to a pronounced increase of the public awareness of toxic cyanobacterial blooms.

A novel heat exchanger including hydrogen and water for heat capturing and combating water scarcity

In today's world, people have been facing different unpleasant phenomena like global warming, water shortage and thermal pollution. Power plants for electricity generation are one of the main sources of greenhouse gases and thermal pollution in aquatic ecosystem. On the other hand, these power plants consume high amount of freshwater for cooling purposes. Water scarcity is a detrimental crisis that the whole world is struggling with it. To combat the thermal pollution, various wet cooling and dry cooling technologies have been introduced and reviewed till today. While wet cooling systems use lots of water, dry cooling ones are not suitable options in warm weather and climates. Here, the need for an alternative element is felt more than ever. So far, water and air have been the main coolants in power generation units. According to specific heat capacities in different substances, hydrogen, by far has the highest amount. So, a novel heat exchanger containing hydrogen and water could be a promising solution for the mentioned issues. This paper focuses on advantages of this heat exchanger from different points of view, however, some assumptions, considerations and calculations should be carried out to have the best performance for this idea. Temperature control is such an important process that should be done in heat exchangers. Hence, a review on a control method has been carried out in this paper. The simulation results have been taken by MATLAB/SIMULINK software.

Investigation of an unusual cluster of illness among staff at a wildlife rescue centre

Abstract When two previously fit and well staff from a wildlife rescue centre were hospitalised in early September 2018 with severe pneumonia and meningitis symptoms, the Health Protection Team began an investigation. Possible diagnoses included influenza and legionella, although it was not flu season, and initial testing proved negative. There were reports of other staff illness over the preceding weeks. The centre had accepted a wide range species over the Summer, including high numbers of gulls and pigeons, and an outbreak of psittacosis was suspected; the patients responded rapidly to doxycycline. An incident management team was rapidly convened to investigate and determine control measures. A testing algorithm was developed: including for Influenza A&B, Urine legionella & pneumococcal antigen; reference laboratory serology testing and real-time PCR for Chlamydia.psittaci; and pan-corona viruses. Case finding was conducted by telephone interviews and a select-survey of all 55 staff gained 46 responses. A series of site visits examined working practices at the site. Avian and environmental sampling was undertaken. A total of 22 staff met the agreed case definition for psittacosis, five of whom were later confirmed. Clinical features ranged from mild to severe. The onset dates of illness ranged from July to September. There was no evidence of person-to-person transmission. Analysis did not show a clear correlation between PPE use and illness. Clinical, microbiological, environmental, veterinary, and epidemiological evidence indicated zoonotic transmission of psittacosis. Variable compliance with PPE, hygiene when handling birds, and disinfection had likely contributed via aerosolization of dust. This was likely exacerbated by very high bird stocks and unusually warm weather conditions. Comprehensive recommendations were made to reduce the chances of future outbreaks, which are generalisable to other countries. Key messages • This was one of the largest clusters of human psittacosis described in a workplace in England. • Biosecurity in animal rescue centres is crucial to limit the chance of psittacosis and other zoonoses.

Asymmetry in Ball Kicking Speed between Preferred and Non-preferred Leg in Young Soccer Players

Kicking ability is one of the most important skills in soccer. It is very important to have a good kicking ability with both feet. The main goal of this research was to determine a ball kicking asymmetry (KA) between preferred and non-preferred leg in young soccer players for the U-15 and the U-17 age category. The second goal was to determine differences in kicking asymmetry (KA) between players of different playing positions. 183 young players in U-15 category as well as 87 players from U-17 age category were tested with simple soccer specific test to evaluate kicking velocity (km/h) with preferred and non-preferred leg using Pocket radar. Testing took place on the artificial grass during dry and warm weather and ball was kicked while stationary at the 11-m spot. Results obtained with Student’s T-test showed that differences in the maximum kicking velocity with the preferred and non-preferred leg were statistically significant (p≤0.05) in both age groups (90.2±8.8 km/h /78.5±9.8 km/h for U-15) and (102.7±6.4 km/h /89.5±9.4 km/h for U-17) which confirmed KA is present. Additionally, univariate analysis of variance (ANOVA) showed that there were significant differences in KA between different playing positions in U-17 group (KA=14.57/9.72/14.1 for defenders, midfielders and attackers, respectively). Soccer kicking can be a quality indicator for assessing the soccer kicking ability. By assessing kicking ability, relevant results can be obtained in a fast, and efficient way and can be utilized in the selection process of young talents.

Diagnosis, Treatment and Prevention of Pediatric Lyme disease

Lyme disease remains a significant public health challenge in the United States, particularly in the Northeast and Midwest regions, and is likely to increase in the coming years with population growth to suburban areas and warmer weather. Lyme disease is a bacterial infection caused by the spirochete, Borrelia burgdorferi, that is transmitted to humans through deer ticks. The presentation of Lyme disease can involve multiple systems with dermatologic, neurologic, rheumatologic, and cardiac symptoms commonly described. However, there is substantial variation in the presentation of Lyme disease, creating a challenge to diagnosis and treatment. The standard treatment for Lyme disease is administration of antibacterial agents. Although the majority of pediatric patients achieve symptom resolution with treatment, a subset continues to experience fatigue, pain, and psychological disturbances known as post-treatment Lyme disease syndrome. Prevention of Lyme disease largely relies on behavioral measures such as wearing long sleeves and pants and checking for ticks given the absence of an effective vaccine. Prophylactic antibiotic treatment is also highly effective for children who have experienced a Ixodes tick bite, occurring in an endemic region with tick attachment for at least 36 hours. Although Lyme disease disproportionately impacts children, the existing literature primarily focuses on its presentation in adults. In this review, we summarize the latest literature surrounding the diagnosis, treatment, and prevention of Lyme disease with a specific emphasis on pediatric populations and the recent advancements in vaccine development.

Porous asphalt mixtures enriched with bamboo fibers as a new approach for future sustainable construction

Porous Asphalt (PA) is a highly permeable asphalt surface used to create and maintain permeable pavements for storm water management and runoff reduction. Under the impacts of repetitive vehicle loads, warm weather, and heavily rainfall, the structure was vulnerable to deterioration from cracking, rutting, stripping, and quick ageing. This research aims to examine the role of bamboo fiber in improving the physical and mechanical properties and overcome the issue related to PA. Among the tests involve are Cantabro loss, permeability, binder draindown, stability and resilient modulus. Two types of PA gradation involved with four different proportion of bamboo fiber (0.2%, 0.3%, 0.4%, 0.5%). From the findings, it could be conducted that the existence of bamboo fiber can significantly improve the PA performance for both gradations. From this study, the utilization of natural fiber as an additive is also promoted and provide significant contribution to the exploration to alternative pavement material.

The effects of warm weather on children’s outdoor heat stress and physical activity in a preschool yard in Gothenburg, Sweden

Hot weather conditions can have negative impacts on the thermal comfort and physical activity of vulnerable groups such as children. The aim of this study is to analyze the effects of warm weather on 5-year-old children’s thermal comfort and physical activity in a preschool yard in Gothenburg, Sweden. In situ measurements were conducted for 1–1.5 h in the early afternoon on 8 days in May, June, and August of 2022. The thermal comfort and physical activity was estimated with GPS-tracks, heart rate monitors, and step counts and compared to observed weather conditions. Results show that physical activity decreases under warmer weather conditions, depicted by a decrease in distance moved, step counts, and highest registered pulse. Moreover, on warm days, the children avoid sunlit areas. For 50% or more of the time spent in sunlit areas, the children are exposed to cautious levels of heat. In shaded areas, on the other hand, the children are less exposed, with five out of 8 days having 50% or more of the time at neutral levels. The study demonstrates the importance of access to shaded areas in preschool yards where children can continue their active play while simultaneously maintaining a safe thermal status.

Optimization of Welding Process of Geomembranes in Biodigesters Using Design of Factorial Experiments

This research focuses on the optimization of the thermofusion process in the construction of biodigesters as it has a direct influence on their quality and durability. The study utilizes factorial experiments and statistical analysis, with particular emphasis on the innovative application of the arcsine transformation. Two 2k factorial designs were developed to account for warm and cold weather. The experiments evaluated factors such as the operator’s experience, wedge sealing temperature, sealing speed, and extruder temperature. The effects on the response variables were analyzed, which included overheating, resistance, and leaks. The study identified significant influences of the operator and the temperature of the wedge sealer in warm weather conditions, while the operator’s influence remained prominent in resistance and leakage tests in cold weather. Data transformation techniques, including the arcsine transformation, were employed to ensure statistical validity. Optimal input variable combinations were identified to maximize resistance and minimize overheating and air leaks. The research emphasizes the importance of optimizing the thermofusion process for biodigester construction, highlighting the role of arcsine transformation in improving statistical analysis. The findings enable practitioners to make informed decisions, leading to improvements in welding processes and overall biodigester quality.

Shifts in intra-annual growth dynamics drive a decline in productivity of temperate trees in Central European forest under warmer climate

Climate change shifts tree growth phenology and dynamics in temperate forests. However, there is still little information on how warming climate changes intra-annual growth patterns and how these changes affect the productivity and carbon uptake of temperate trees. To address this knowledge gap, we used high-precision growth data from automatic dendrometers to quantify the impacts of unusually warm weather in 2022 (hot year) on growth phenology, dynamics and aboveground biomass (AGB) production in eight common temperate species (both conifers and broadleaved) in the Czech Republic. Mixed-effect models were used to investigate inter-annual changes in the start, end, and length of the growing season and intra-annual growth dynamics. We also modelled how changes in growth phenology, growth rates, and tree size affected yearly AGB production of individual trees. In the hot year, the growth started 5 days earlier, peaked 22 days earlier and ended 20 days earlier than in the climatically normal year, resulting in a shorter growing season with fewer growing days. AGB production decreased 36 % in the hot year, mainly due to fewer growing days and lower maximum growth rates, but with significant variation among tested species. The decline in AGB production in the hot year was most significant in the most productive species, which were also the species with the greatest reduction in the number of growing days. Tree size strongly enhanced AGB production, but its effect did not change with climate variation. Our findings suggest that climate change is likely to advance but also shorten the growing season of temperate trees, resulting in lower biomass production and carbon uptake. The results also indicate that the fast-growing and highly productive temperate tree species will have their growth reduced most by climate change, which will increasingly limit their high carbon sequestration potential.

Analysis of the Effects of Warm Weather Conditions on Fuel Tank Flammability

Analysis of the Effects of Warm Weather Conditions on Fuel Tank Flammability

Optimal application of dextranase in a Louisiana sugarcane factory to mitigate severe processing problems after a freeze

A Louisiana (LA) state-wide severe freeze occurred from 23–26 December 2022, which was followed by warm weather and occasional fog causing severe deterioration of all sugarcane varieties in the fields. Dextranase was applied to break down dextran (glucose polysaccharide) into smaller, more manageable molecules, which can improve processing. The efficiency of dextranase application depends on the pH, dry solids content rds (Brix), temperature, retention time, and agitation, type, activity and dosage of the applied dextranase as well as the enzyme/substrate ratio. Dextranase applications to juice are more efficient and economical than adding to syrup because the high temperature and dry solids content of syrups impede its action. Heating juice to 50 °C and pre-liming to pH 5.9 is optimal for dextranase application, but after 50 °C the activity falls off quickly. One LA factory built a new juice liming system that was quickly modified for optimal dextranase application after the freeze. Optimum conditions for concentrated dextranase (92700 DU/mL) applied were: rds <25%, temperature 50 °C, juice pH = 5.90, 1:10 working solution of concentrated dextranase up to 5 mg/L dosage; retention time = 10 min; 0.624 s–1 agitation. These conditions were successful with >80% breakdown of Haze dextran and minimized processing problems associated with the freeze. Retention time was not as important as temperature and the pH of the juice. The use of dextranase allowed this factory to (i) process all the field sugarcane from the growers even when sucrose concentrations were very low (down to ~56% juice purities on the last day of cane delivery), (ii) continue to crystallize sugar at acceptable crystallization rates, (iii) keep crystal elongation factors to only 2.3 and largely prevent needle formation, and (iv) allow the production of raw sugar with no dextran penalties from the refinery.

Water level drawdown makes boreal peatland vegetation more responsive to weather conditions.

Climate warming and projected increase in summer droughts puts northern peatlands under pressure by subjecting them to a combination of gradual drying and extreme weather events. The combined effect of those on peatland functions is poorly known. Here, we studied the impact of long-term water level drawdown (WLD) and contrasting weather conditions on leaf phenology and biomass production of ground level vegetation in boreal peatlands. Data were collected during two contrasting growing seasons from a WLD experiment including a rich and a poor fen and an ombrotrophic bog. Results showed that WLD had a strong effect on both leaf area development and biomass production, and these responses differed between peatland types. In the poor fen and the bog, WLD increased plant growth, while in the rich fen, WLD reduced the growth of ground level vegetation. Plant groups differed in their response, as WLD reduced the growth of graminoids, while shrubs and tree seedlings benefited from it. In addition, the vegetation adjusted to the lower WTs, was more responsive to short-term climatic variations. The warmer summer resulted in a greater maximum and earlier peaking of leaf area index, and greater biomass production by vascular plants and Sphagnum mosses at WLD sites. In particular, graminoids benefitted from the warmer conditions. The change towards greater production in the WLD sites in general and during the warmer weather in particular, was related to the observed transition in plant functional type composition towards arboreal vegetation.

Impact of meteorological parameters and air pollutants on airborne concentration of Betula pollen and Bet v 1 allergen

The intensity of birch pollen season is expressed by seasonal pollen integral (SPIn, the sum of the mean daily pollen concentration during the birch pollination period) and the amount of Bet v 1 allergen released per birch pollen grain expressed by pollen allergen potency (PAP). Betula pollen and Bet v 1 allergen were simultaneously measured in the air of Bratislava from 2019 to 2022 by using two Burkard traps (Hirst-type and cyclone) in order to evaluate the causes of the seasonal variation in the SPIn and PAP levels. The highest SPIn (19,975 pollen/m3) was observed in 2022 and the lowest one (1484 pollen/m3) in 2021. The average daily PAP level (4.0 pg Bet v 1/pollen) was highest in 2019 and lowest (2.5 pg Bet v 1/pollen) in 2020. We found that seasonal variation in SPIn was associated mainly with the changes in environmental conditions during the pre-season period, whereas the year-to-year variation in PAP levels was attributed to environmental conditions during both pre- and in-season periods. Our results indicate that rainy weather in June 2020 and cold overcast weather in January‒February 2021 resulted in low SPIn in 2021. On the other hand, dry weather in June 2021 and warm weather in January‒February 2022 resulted in high SPIn in 2022. The low average daily PAP level in 2020 was associated with (1) low levels of gaseous air pollutants in March, when the ripening of pollen takes place; (2) an earlier start of the birch main pollen season (MPS); and (3) dry weather during the MPS. On the other hand, high PAP level in 2019 was associated with higher levels of air pollutants in March and during the MPS.

Factors associated with bark beetle infestations of Colorado Plateau ponderosa pine using repeatedly-measured field plots

Decades of research have brought increasing focus to the biotic and abiotic factors associated with bark beetle infestation of North American conifers. Information is lacking, however, regarding beetle-caused mortality for ponderosa pine of the Colorado Plateau. From 1995 to 2019, we installed and periodically remeasured permanent plots in this forest type with a goal of identifying factors related to infestation probability including tree and stand characters, and abiotic factors such as temperature and precipitation. Forty-eight sites were distributed throughout the Colorado Plateau, each with two transects of 10 contiguous ∼ 0.04 ha circular plots. Stand and tree conditions were measured or interpolated for each year from plot establishment in 1995 until the final measurements in 2019. Temperature, precipitation, and other abiotic conditions were estimated from Daymet interpolations. We used a generalized linear mixed model to identify significant explanatory variables resulting in the best accuracy of predicting stem-level bark beetle-caused pine mortality. Tree and stand conditions were found related to the probability of infestation. Pines >15.2 cm dbh were more likely to become infested compared to pines below that threshold; no relationship was found above that breakpoint. Similarly, stems 80–180 years old had elevated probability of infestation compared to stems < 80 years; stems > 180 years were intermediate. Pines with poor crown vigor (low crown volume, suppressed or intermediate canopy position) were more likely to become infested compared to pines with good crown vigor (high crown volume, dominant or open grown canopy position). Pine basal area (BA), a surrogate for intra-species competition, was positively related to probability of infestation. Pine BA infested the previous year, a surrogate for beetle population size, was also positively related to probability of infestation. Several drought- and precipitation-related variables resulted in similar model accuracy. Best model fit among these, by a slight margin, was contemporaneous climate water deficit (CWD), a measure of plant water stress, summed from April-August. Increasing CWD was associated with increased probability of infestation. Finally, counts of days above 16 °C the previous year were negatively related to infestation probability. That is, relatively warm weather during the previous year was associated with reduced beetle success, possibly because it can result in fractional beetle life cycles that disrupt synchronized attacks on new hosts or leave overwintering brood in less cold hardy life stages.