TY - JOUR T1 - Impact of minimum winter temperatures on the population dynamics of Dendroctonus frontalis JF - Ecological Applications Y1 - 2007 A1 - Khai Tran, J. A1 - Ylioja, Tiina A1 - Billings, Ronald F. A1 - Regniere, Jacques A1 - Ayres, Matthew P. SP - 882 EP - 899 KW - Dendroctonus frontalis AB - Predicting population dynamics is a fundamental problem in applied ecology. Temperature is a potential driver of short-term population dynamics, and temperature data are widely available, but we generally lack validated models to predict dynamics based upon temperatures. A generalized approach involves estimating the temperatures experienced by a population, characterizing the demographic consequences of physiological responses to temperature, and testing for predicted effects on abundance. We employed this approach to test whether minimum winter temperatures are a meaningful driver of pestilence from Dendroctonus frontalis ( the southern pine beetle) across the southeastern United States. A distance-weighted interpolation model provided good, spatially explicit, predictions of minimum winter air temperatures ( a putative driver of beetle survival). A Newtonian heat transfer model with empirical cooling constants indicated that beetles within host trees are buffered from the lowest air temperatures by; [approximately]1-4[degree]C ( depending on tree diameter and duration of cold bout). The life stage structure of beetles in the most northerly outbreak in recent times ( New Jersey) were dominated by prepupae, which were more cold tolerant (by >3[degree]C) than other life stages. Analyses of beetle abundance data from 1987 to 2005 showed that minimum winter air temperature only explained 1.5% of the variance in interannual growth rates of beetle populations, indicating that it is but a weak driver of population dynamics in the southeastern United States as a whole. However, average population growth rate matched theoretical predictions of a process-based model of winter mortality from low temperatures; apparently our knowledge of population effects from winter temperatures is satisfactory, and may help to predict dynamics of northern populations, even while adding little to population predictions in southern forests. Recent episodes of D. frontalis outbreaks in northern forests may have been allowed by a warming trend from 1960 to 2004 of 3.3[degree]C in minimum winter air temperatures in the southeastern United States. Studies that combine climatic analyses, physiological experiments, and spatially replicated time series of population abundance can improve population predictions, contribute to a synthesis of population and physiological ecology, and aid in assessing the ecological consequences of climatic trends. VL - 17 SN - 1051-0761 ER - TY - JOUR T1 - Presence and Diversity of Streptomyces in Dendroctonus and Sympatric Bark Beetle Galleries Across North America JF - Microbial Ecology Y1 - 2011 A1 - Hulcr, Jiri A1 - Adams, Aaron S. A1 - Raffa, Kenneth A1 - Hofstetter, Richard W. A1 - Klepzig, Kier D. A1 - Currie, Cameron R. SP - 759 EP - 768 KW - Dendroctonus frontalis KW - Dendroctonus rufipennis AB - Recent studies have revealed several examples of intimate associations between insects and Actinobacteria, including the Southern Pine Beetle Dendroctonus frontalis and the Spruce Beetle Dendroctonus rufipennis. Here, we surveyed Streptomyces Actinobacteria co-occurring with 10 species of Dendroctonus bark beetles across the United States, using both phylogenetic and community ecology approaches. From these 10 species, and 19 other scolytine beetles that occur in the same trees, we obtained 154 Streptomyces-like isolates and generated 16S sequences from 134 of those. Confirmed 16S sequences of Streptomyces were binned into 36 distinct strains using a threshold of 0.2% sequence divergence. The 16S rDNA phylogeny of all isolates does not correlate with the distribution of strains among beetle species, localities, or parts of the beetles or their galleries. However, we identified three Streptomyces strains occurring repeatedly on Dendroctonus beetles and in their galleries. Identity of these isolates was corroborated using a house-keeping gene sequence (efTu). These strains are not confined to a certain species of beetle, locality, or part of the beetle or their galleries. However, their role as residents in the woodboring insect niche is supported by the repeated association of their 16S and efTu from across the continent, and also having been reported in studies of other subcortical insects. VL - 61 SN - 0095-3628 ER - TY - JOUR T1 - Temperature-dependent effects on mutualistic, antagonistic, and commensalistic interactions among insects, fungi and mites JF - Community Ecology Y1 - 2007 A1 - Hofstetter, R. W. A1 - Dempsey, T. D. A1 - Klepzig, K. D. A1 - Ayres, M. P. SP - 47 EP - 56 KW - Dendroctonus frontalis AB - The relative abundance and nature of associations between symbiotic species can be affected by abiotic conditions with consequences for population dynamics. We investigated the effects of temperature on the community of mites and fungi associated with the southern pine beetle, Dendroctonus frontalis, an important pest of pine forests in the southern United States. First, we determined whether the growth rates of mutualistic and antagonistic fungi associated with D. frontalis differed in their responses to temperature. Second, we tested the effects of temperature on the abundance of, and interactions among, fungi, mites and beetles within D. frontalis-infested trees. Fungi differed in their growth responses to temperature, resulting in changes in fungal-beetle associations. Mite species associated with D. frontalis also differed in their responses to temperature, resulting in different mite communities associated with bark beetle progeny. The effects of temperature on beetle reproduction could not be assessed because of high wood borer density, but inter-relations among surviving beetles, mites and fungi were altered by temperature. Results support the hypothesis that temperature can produce direct and indirect effects on the web of mutualistic and antagonistic relationships within the community of D. frontalis and their symbiotic mites and fungi. VL - 8 SN - 1585-8553 ER - TY - JOUR T1 - Influence of temperature on spring flight initiation for southwestern ponderosa pine bark beetles (Coleoptera: Curculionidae, Scolytinae) JF - Environmental Entomology Y1 - 2008 A1 - Gaylord, M. L. A1 - Williams, K. K. A1 - Hofstetter, R. W. A1 - McMillin, J. D. A1 - Degomez, T. E. A1 - Wagner, M. R. SP - 57 EP - 69 KW - Dendroctonus brevicornis KW - Dendroctonus frontalis KW - Dendroctonus ponderosae KW - Dendroctonus valens KW - Enoclerus KW - Ips lecontei KW - Ips pini AB - Determination of temperature requirements for many economically important insects is a cornerstone of pest management. For bark beetles (Coleoptera: Curculionidae, Scolytinae), this information can facilitate timing of management strategies. Our goals were to determine temperature predictors for flight initiation of three species of Ips bark beetles, five species of Dendroctonus bark beetles, and two genera of bark beetle predators, Enoclerus spp. (Coleoptera: Cleridae) and Temnochila chlorodia (Mannerheim) (Coleoptera: Ostomidae), in ponderosa pine forests of northcentral Arizona. We quantified beetle flight activity using data loggers and pheromone-baited funnel traps at 18 sites over 4 yr. Ambient air temperature was monitored using temperature data loggers located in close proximity to funnel traps. We analyzed degree-day accumulation and differences between minimum, average, and maximum ambient temperature for the week before and week of first beetle capture to calculate flight temperature thresholds. Degree-day accumulation was not a good predictor for initiation of beetle flight. For all species analyzed other than D. adjunctus Blandford, beetles were captured in traps only when springtime temperatures exceeded 15.0[degree]C. D. adjunctus was collected when maximum temperatures reached only 14.5[degree]C. Once initial flights had begun, beetles were often captured when maximum ambient air temperatures were below initial threshold temperatures. Maximum and average air temperatures were a better predictor for beetle flight initiation than minimum temperature. We establish a temperature range for effective monitoring of bark beetles and their predators, and we discuss the implications of our results under climate change scenarios VL - 37 SN - 0046-225X ER - TY - JOUR T1 - Differential impacts of the southern pine beetle, Dendroctonus frontalis, on Pinus palustris and Pinus taeda JF - Canadian Journal of Forest Research Y1 - 2007 A1 - Friedenberg, Nicholas A. A1 - Whited, Brenda M. A1 - Slone, Daniel H. A1 - Martinson, Sharon J. A1 - Ayres, Matthew P. SP - 1427 EP - 1437 KW - Dendroctonus frontalis AB - Patterns of host use by herbivore pests can have serious consequences for natural and managed ecosystems but are often poorly understood. Here, we provide the first quantification of large differential impacts of the southern pine beetle, Dendroctonus frontalis Zimmermann, on loblolly pine, Pinus taeda L., and longleaf pine, Pinus palustris P. Mill., and evaluate putative mechanisms for the disparity. Spatially extensive survey data from recent epidemics indicate that, per square kilometre, stands of loblolly versus longleaf pine in four forests (380[long dash]1273 km2) sustained 3[long dash]18 times more local infestations and 3[long dash]116 times more tree mortality. Differences were not attributable to size or age structure of pine stands. Using pheromone-baited traps, we found no differences in the abundance of dispersing D. frontalis or its predator Thanasimus dubius Fabricius between loblolly and longleaf stands. Trapping triggered numerous attacks on trees, but the pine species did not differ in the probability of attack initiation or in the surface area of bark attacked by growing aggregations. We found no evidence for postaggregation mechanisms of discrimination or differential success on the two hosts, suggesting that early colonizers discriminate between host species before a pheromone plume is present. VL - 37 SN - 0045-5067 ER - TY - JOUR T1 - Temperature extremes, density dependence, and southern pine beetle (Coleoptera: Curculionidae) population dynamics in east Texas JF - Environmental Entomology Y1 - 2008 A1 - Friedenberg, Nicholas A. A1 - Sarkar, Sudipta A1 - Kouchoukos, Nicholas A1 - Billings, Ronald F. A1 - Ayres, Matthew P. SP - 650 EP - 659 KW - Dendroctonus frontalis AB - Previous studies of the southern pine beetle, Dendroctonus frontalis Zimm., established that its population in east Texas responds to a delayed density-dependent process, whereas no clear role of climate has been determined. We tested two biological hypotheses for the influence of extreme temperatures on annual southern pine beetle population growth in the context of four alternative hypotheses for density-dependent population regulation. The significance of climate variables and their interaction with population regulation depended on the model of density dependence. The best model included both direct and delayed density dependence of a cubic rather than linear form. Population growth declined with the number of days exceeding 32[degree]C, temperatures previously reported to reduce brood survival. Density dependence also changed with the number of hot days. Growth was highest in years with average minimum winter temperatures. Severely cold winters may reduce Survival, whereas warm winters may reduce the efficiency of spring infestation formation. Whereas most previous studies have incorporated climate as an additive effect on growth, we found that the form of delayed density dependence changed with the number of days >32[degree]C. The interaction between temperature and regulation, a potentially common phenomenon in ecology, may explain why southern pine beetle outbreaks do not occur at perfectly regular intervals. Factors other than climate, such as forest management and direct suppression, may have contributed significantly to the timing, severity, and eventual cessation of outbreaks since the mid-1950s. VL - 37 SN - 0046-225X ER - TY - JOUR T1 - Restoration of shortleaf pine (Pinus echinata)-hardwood ecosystems severely impacted by the southern pine beetle (Dendroctonus frontalis) JF - Forest Ecology and Management Y1 - 2012 A1 - Elliott, Katherine J. A1 - Vose, James M. A1 - Knoepp, Jennifer D. A1 - Clinton, Barton D. SP - 181 EP - 200 KW - Dendroctonus frontalis AB - In the Southern Appalachian Mountains of eastern USA, pine-hardwood ecosystems have been severely impacted by the interactions of past land use, fire exclusion, drought, and southern pine beetle (SPB, Dendroctonus frontalis). We examined the effects of restoration treatments: burn only (BURN); cut + burn on dry sites (DC + B); cut + burn on sub-mesic sites (MC + B); and reference sites (REF; no cutting or burning) on shortleaf pine-hardwood forests. We also evaluated the effectiveness of seeding native bluestem grasses. Structural (down wood, live and dead standing trees, shrubs, herbaceous layer) and functional (forest floor mass, C, and N; soil C, N, P. and cations; and soil solution N and P) attributes were measured before and the first and second growing seasons after treatment. We used path analysis to test our conceptual model that restoration treatments will have direct and indirect effects on these ecosystems. Total aboveground mass loss ranged from 24.33 Mg ha-1 on the BURN to 74.44 Mg ha-1 on the DC + B treatment; whereas, REF gained 13.68 Mg ha-1 between pre-burn and post-burn. Only DC + B sites had increased soil NO3-N, NH4-N Ca, Mg, and PO4-P and soil solution NO3-N, NH4-N, O-PO4 for several months. We found a significant increase in the density of oak species (Quercus alba, Q. coccinea, Q. montana, Q. rubra, and Q. velutina) on all burn treatments. However, oaks accounted for a smaller proportion of the total stem density than red maple, other tree species, and shrubs. The high densities of woody species other than oaks, coupled with the fast growth rates of some of these species, suggests that oaks will continue to be at a competitive disadvantage in these pine-hardwood communities through time, without further intervention. Pine regeneration was not improved on any of our burned sites with little to no recruitment of pines into the understory after two years and the pine saplings that were present before the burns were killed by fire on all sites. We found an increase in herbaceous layer cover and richness on all fire treatments. DC + B had higher bluestem grass cover than the other treatments, and it was the only treatment with increased bluestem grass cover between the first (2.96%, SE = 0.29) and second (6.88%, SE = 0.70) growing seasons. Our path model showed that fire severity explained a large proportion of the variation in overstory response; and fire severity and overstory response partially explained soil NO3-N. These variables, directly and indirectly, explained 64% of the variation in soil solution NO3-N at 30 cm soil depth (within the rooting zone for most plants). We found a good-fit path model for herbaceous layer response in the second growing season, where fire severity had direct effects on overstory and herbaceous layer responses and indirect effects on herbaceous layer response mediated through overstory response. Our path model explained 46% and 42% of the variation in herbaceous layer cover and species richness, respectively. Published by Elsevier B.V. VL - 274 SN - 0378-1127 ER - TY - JOUR T1 - Predicting County-Level Southern Pine Beetle Outbreaks From Neighborhood Patterns JF - Environmental Entomology Y1 - 2011 A1 - Duehl, Adrian A1 - Bishir, John A1 - Hain, Fred P. SP - 273 EP - 280 KW - Dendroctonus frontalis AB - The southern pine beetle (Dendroctonus frontalis Zimmermann, Coleoptera: Curculionidae) is the most destructive insect in southern forests. States have kept county-level records on the locations of beetle outbreaks for the past 50 yr. This study determined how accurately patterns of county-level infestations in preceding years could predict infestation occurrence in the current year and if there were emergent patterns that correlated strongly with beetle outbreaks. A variety of methods were tested as infestation predictors, including quantification of either the exact locations of infested grid cells during one or two preceding years, or the neighborhood infestation intensity (number of infested cells in a neighborhood) in these years. The methods had similar predictive abilities, but the simpler methods performed somewhat better than the more complex ones. The factors most correlated with infestations in future years were infestation in the current year and the number of surrounding counties that were infested. Infestation history helped to predict the probability of future infestations in a region, but county-level patterns alone left much of the year-to-year variability unexplained. VL - 40 SN - 0046-225X ER - TY - JOUR T1 - Southern pine beetle regional outbreaks modeled on landscape, climate and infestation history JF - Forest Ecology and Management Y1 - 2011 A1 - Duehl, Adrian J. A1 - Koch, Frank H. A1 - Hain, Fred P. SP - 473 EP - 479 KW - Dendroctonus frontalis AB - The southern pine beetle (Dendroctonus frontalis, SPB) is the major insect pest of pine species in the southeastern United States. It attains outbreak population levels sufficient to mass attack host pines across the landscape at scales ranging from a single forest stand to interstate epidemics. This county level analysis selected and examined the best climatic and landscape variables for predicting infestations at regional scales. The analysis showed that, for a given county, the most important factor in predicting outbreaks was that the county was classified as in outbreak status in the previous year. Other important factors included minimum winter temperature and the greatest difference between the average of daily minimums and a subsequent low temperature point, precipitation history either seasonally in the previous year or difference from average over the previous 2 years, the synchronizing effect of seasonal temperatures on beetle populations and the relative percentage of total forest area composed of host species. The statistical models showed that climatic variables are stronger indicators of outbreak likelihood than landscape structure and cover variables. Average climatic conditions were more likely to lead to outbreaks than extreme conditions, supporting the notion of coupling between a native insect and its native host. Still, some extreme events (i.e., periods of very low temperature or very high precipitation) did precede beetle infestation. This analysis suggested that there are predisposing and inciting factors at the large scale but the driving factors leading to individual infestations operate at smaller scales. VL - 261 SN - 0378-1127 ER - TY - JOUR T1 - Kairomonal response of coleopterans associated with Dendroctonus frontalis and two Ips species (Coleoptera: Curculionidae) in forest of Chiapas, Mexico JF - Revista Mexicana De Biodiversidad Y1 - 2008 A1 - Dominguez-Sanchez, Bernando A1 - Macias-Samano, Jorge E. A1 - Ramirez-Marcial, Neptali A1 - Leon-Cortes, Jorger L. SP - 175 EP - 183 KW - Dendroctonus frontalis KW - Ips AB - We assessed the bark beetle diversity and the response of associated predators to aggregation pheromones in pine forests in Chiapas, Mexico. From June to October 2006, 40 Lindgren funnel traps were established with different baits that included frontalin, ipsenol and ipsdienol pheromones and a control (without pheromone). We registered the attractiveness of frontalin to the bark beetle Dendroctonus frontalis (Zimmermann), and ipsenol and ipsdienol to Ips spp. Kairomonal specific response of the predators Temnochila chlorodia (Mannerheim), Enoclerus ablusus (Ban) and Elacatis sp. was detected. We registered an important increase in abundance of bark beetles and predators during the summer to the beginning of fall. T. chlorodia exhibited differential attraction to the three pheromones evaluated, whereas E. ablusus, Elacatis sp. and Leptostylus sp. were significantly attracted to ipsenol and ipsdienol. This is the first report of kairomonal response of the phytophagous Leptostylus sp. (Cerambycidae) for Mexico. Our results showed that inter-and intra-specific communication between different bark beetles and associated species may occur, which promotes competitive and predator interaction between them. VL - 79 ER - TY - JOUR T1 - The effect of larval predators Thanasimus dubius (Coleoptera: Cleridae), produced by an improved system of rearing, against the southern pine beetle Dendroctonus frontalis (Coleoptera: Curculionidae) JF - Biological Control Y1 - 2012 A1 - Costa, Arnaud A1 - Reeve, John D. SP - 1 EP - 6 KW - Dendroctonus frontalis AB - The southern pine beetle, Dendroctonus frontalis (Coleoptera: Curculionidae) (SPB), is known to be a major bark beetle pest of pines throughout the southeastern United States. A common predator of bark beetles, Thanasimus dubius (Coleoptera: Cleridae), has been suggested to play a prevalent role on SPB dynamics. Evaluations of T. dubius have been limited by rearing methods; an artificial diet for larval T. dubius exists, and preservatives such as sorbic acid could help to maximize diet shelf-life and enhance the efficiency of the rearing system. The effects of sorbic acid at different concentrations (0%, 0.1% and 0.2%) in the larval diet for T. dubius were measured, and the effects of increased feeding time intervals (2-3 vs. 5 days) on predator performance evaluated. In addition, an experimental bioassay was conducted where newly hatched T. dubius larvae were released at four densities (0, 50, 100, and 200 per log) on pine logs infested by SPB. Sorbic acid in the diet reduced female fecundity (by 20-40%), but did not affect adult T. dubius size or longevity. However, using this preservative may not be necessary because it had no effect on the overall efficiency of the rearing system, while refreshing the larval diet every 5 days (compared with 2-3 days) did improve its efficiency, even without sorbic acid. The release of larval T. dubius resulted in a highly significant effect on the SPB ratio of increase (RI). This experiment was facilitated by the improvements in our rearing methods. Published by Elsevier Inc. VL - 60 SN - 1049-9644 ER - TY - JOUR T1 - Development of a satellite-based hazard rating system for Dendroctonus frontallis frontalis (Coleoptera: Scolytidae) in the Ouachita Mountains of Arkansas JF - Journal of Economic Entomology Y1 - 2007 A1 - Cook, Stephen A1 - Cherry, Shane A1 - Humes, Karen A1 - Guldin, James A1 - Williams, Christopher SP - 381 EP - 388 KW - Dendroctonus frontalis AB - The southern pine beetle, Dendroctonus frontalis Zimmermann (Coleoptera: Scolytidae), is the most damaging forest insect pest of pines (Pinus spp.) throughout the southeastern United States. Hazard rating schemes have been developed for D. frontalis, but for these schemes to be accurate and effective, they require extensive on-site measurements of stand attributes such as host density, age, and basal area. We developed a stand bazard-rating scheme for several watersheds in the Ouachita Highlands of Arkansas based upon remotely sensed data and a geographic information system. A hazard model was developed using stand attributes (tree species, stand age and density, pine basal area, and landform information) and was used to establish baseline hazard maps for the watersheds. Landsat 7 ETM+ data were used for developing new hazard maps. Two dates of Landsat imagery were used in the analyses (August 1999 and October 1999). The highest correlations between hazard rating scores and remotely sensed variables from either of the dates included individual Landsat 7 ETM+ bands in the near- and mid-infrared regions as well as variables derived from various bands (i.e., Tasseled cap parameters, principal component parameters, and vegetation indices such as the calculated simple ratio and normalized difference vegetation index). Best subset regression analyses produced models to predict stand hazard to southern pine beetle that consisted of similar variables that resembled but were more detailed than maps produced using inverse distance weighted techniques. Although the models are specific for the study area, with modifications, they should be transferable to geographically similar areas. VL - 100 SN - 0022-0493 ER - TY - JOUR T1 - Forest composition following overstory mortality from southern pine beetle and associated treatments JF - Canadian Journal of Forest Research Y1 - 2008 A1 - Coleman, T. W. A1 - Clarke, Stephen R. A1 - Meeker, James R. A1 - Rieske, L. K. SP - 1406 EP - 1418 KW - Dendroctonus frontalis AB - Bark beetle caused mortality continues to play a critical role in determining the composition and structure of forests in North America, and revegetation dynamics following these disturbances are poorly understood. We assessed forest composition following southern pine beetle, Dendroctonus frontalis Zimmermann, mortality and associated cut and leave suppression, and compared them with undisturbed loblolly pine, Pinus taeda L., stands in Texas. Abundant hardwood regeneration dominated the understory, with little loblolly pine regeneration following either mortality event. Disturbances eliminated loblolly pine dominance in these even-aged stands, thus stratifying forest structure and apparently increasing stem density (stems[center dot]ha[long dash]1), richness (species[center dot]ha[long dash]1), and diversity (ha) in the lower strata. Aspect and elevation, presumably through influences on site moisture, were the primary gradients associated with vegetation variation in the canonical correspondence analyses for new regeneration. Mortality from Dendroctonus and cut and leave practices shifted loblolly pine communities to mixed upland hardwoods in model predictions generated by the southern variant of the Forest Vegetation Simulator. In addition to being an effective bark beetle control, cut and leave suppression did not alter predicted forest composition 50 years hence when compared with unsuppressed bark beetle-caused mortality. Because of the predicted shift to hardwood domination and a low pine basal area, it is expected that mortality from D. frontalis and cut and leave will substantially reduce future hazards from D. frontalis outbreaks. VL - 38 SN - 0045-5067 ER - TY - JOUR T1 - Description of Parasitorhabditis frontali n. sp (Nemata: Rhabditida) from Dendroctonus frontalis Zimmermann (Coleoptera: Scolytidae) JF - Journal of Nematology Y1 - 2010 A1 - Carta, L. K. A1 - Bauchan, G. A1 - Hsu, C. Y. A1 - Yuceer, C. SP - 46 EP - 54 KW - Dendroctonus frontalis AB - A new Parasitorhabditis species with males and females was discovered from the southern pine beetle Dendroctonus frontalis and its galleries in loblolly pine. Pinus taeda, growing in Mississippi. Females of the new species have a cupola-shaped tail with a small spike; males possess a 2 + (3+2) + 3 ray pattern on the tail fan with ray 10 reaching the margin, and a distinctive stomatal tooth. Parasitorhabditis frontali n. sp. has some similarities to P. hylurgi Massey, 1974 from Hylurgops pinifex in New York, USA, P. terebranus Massey, 1974 from D. terebrans (Olivier, 1795) in Texas USA, P. ligniperdae Fuchs, 1915 from Hylergops ligniperda (Fabricius, 1787) and P dendroctoni Ruhm, 1956 from D. micans (Kugelann, 1794) in Europe, P alert Fuchs, 1915 isolated from the beetle Hylastes ater (Paykull, 1800) in Germany and P. malii Devdariani and Kakulia, 1970 from Scolytus mali (Bechstein, 1805) within the republic of Georgia. Morphometrics for 44 species of Parasitorhabditis are provided to update older keys. Parasitorhabditis frontali n. sp. was initially grown on Malt Extract (ME) agar with its own microbial contaminants that included a bacterium and fungus. The nematode also grew and reproduced after slices of ME agar with nematodes and microbial contaminants were transferred to water agar. It was killed by E. coil on NGM agar plates commonly used to raise other Rhabditida. Drawings of diagnostic anatomy and low-temperature SEM images of bodies, heads, and tails are provided for cultured specimens from pine beetle frass. VL - 42 SN - 0022-300X ER - TY - JOUR T1 - Simulating the reciprocal interaction of forest landscape structure and southern pine beetle herbivory using LANDIS JF - Landscape Ecology Y1 - 2008 A1 - Cairns, David M. A1 - Lafon, Charles W. A1 - Waldron, John D. A1 - Tchakerian, Maria A1 - Coulson, Robert N. A1 - Klepzig, Kier D. A1 - Birt, Andrew G. A1 - Xi, Weimin SP - 403 EP - 415 KW - Dendroctonus frontalis AB - The reciprocal interaction of landscape structure and ecological processes is a cornerstone of modern landscape ecology. We use a simulation model to show how landscape structure and herbivory interact to influence outbreaks of southern pine beetle (Dendroctonus frontalis Zimmermann) in a landscape representative of the southern Appalachian Mountains, USA. We use LANDIS and its biological disturbance agent module to simulate the effects of landscape composition (proportion of landscape in host area) and host aggregation on the size and severity of insect outbreaks and the persistence of the host species, Table Mountain Pine (Pinus pungens Lamb.). We find that landscape composition is less important in the modeled landscapes than host aggregation in structuring the severity of insect outbreaks. Also, simulated southern pine beetle outbreaks over time tend to decrease the aggregation of host species on the landscape by fragmenting large patches into smaller ones, thereby reducing the severity of future outbreaks. Persistence of Table Mountain pine decreases throughout all simulations regardless of landscape structure. The results of this study indicate that when considering alternative restoration strategies for insect-affected landscapes, it is necessary to consider the patterns of hosts on the landscape as well as the landscape composition. VL - 23 SN - 0921-2973 ER - TY - JOUR T1 - Documentation and user guides for SPBLOB: a computer simulation model of the joint population dynamics for loblolly pine and the southern pine beetle JF - U S Forest Service General Technical Report SRS Y1 - 2009 A1 - Bishir, John A1 - Roberds, James A1 - Strom, Brian A1 - Wan, Xiaohai SP - i EP - vii, 1, 3 KW - Dendroctonus frontalis AB - SPBLOB is a computer simulation model for the interaction between loblolly pine (Pinus taeda L.), the economically most important forest crop in the United States, and the southern pine beetle (SPB: Dendroctonus frontalis Zimm.), the major insect pest for this species. The model simulates loblolly pine stands from time of planting until harvest. It mimics day-to-day changes in SPB populations, and the associated tree mortality caused by these bark beetles. In addition, it provides yearly updates of tree mortality due to competition and of growth for the surviving trees. Chiely, the model and its simulation codes are designed to function as research tools for investigating the inluence of stand properties on SPB activities, and of the reciprocal impact of beetles on tree mortality. Model output relates to both trees and beetles. Simulations provide daily and yearly luctuations in the size, composition, and spread of beetle populations within a stand. Stand types (e.g., plantations derived from seedlings or from clonally generated materials) can be compared in terms of average total merchantable volume of timber per acre at time of harvest and/or by average proportions of surviving trees. Average stand yields in the presence of beetles can also be compared with those when beetles are absent, thus providing a basis for estimating the real cost of beetle damage in loblolly stands. In this Documentation we briely describe the model, then outline the concepts and structure upon which the SPBLOB simulation source code is based. The included User Guides specify the input information regarding a loblolly stand and its environment required to run two executable Simulation Codes - a single-stand Interactive Simulation code, in which a user can specify features they wish the simulated stand to possess, and a Multiple-Simulation code that can be used to run large numbers of independent replicates of various stand designs. These Guides also describe the extensive variety of information about simulated tree and beetle populations that can be retrieved during simulations. VL - 114 ER - TY - JOUR T1 - A Methodology for Assessing Annual Risk of Southern Pine Beetle Outbreaks Across the Southern Region Using Pheromone Traps JF - U S Forest Service General Technical Report PNW Y1 - 2010 A1 - Billings, Ronald F. A1 - Upton, William W. SP - 73 EP - 85 KW - Dendroctonus frontalis AB - An operational system to forecast infestation trends (increasing, static, declining) and relative population levels (high, moderate, low) of the southern pine beetle (SPB), Dendroctonus frontalis, has been implemented in the Southern and Eastern United States. Numbers of dispersing SPB and those of a major predator (the clerid beetle, Thanasimus dubius) are monitored with multiple-funnel traps baited with the SPB aggregation pheromone frontalin and host volatiles. One to three traps are placed in each county or national forest ranger district to be surveyed for 4 consecutive weeks during the spring, to coincide with the long-range dispersal of SPB. The average number of SPB per trap per day and the ratio of SPB to total catch of SPB and clerids in the current and previous year for the same trapping location are the variables used for predicting infestation trends and population levels for the remainder of the year. An analysis of predicted and actual SPB infestation trends and population levels for 16 States and up to 19 consecutive years (1987-2005) documents the accuracy of the annual prediction system. From 1987 to 1998, predictions at the State level, validated by subsequent infestation detection records for the specific year, proved accurate 68 percent of the time (range 42 to 83 percent) for SPB infestation trend and 69 percent of the time (range 42 to 92 percent) for population level. From 1999 to 2005, the mean accuracy of predictions of SPB infestation trend improved to 82 percent for all States combined (range 71 to 100 percent); mean predictions for population level for States increased in accuracy to 74 percent (range 43 to 100 percent). Despite system limitations, forest managers have come to depend on this early warning system to predict pending outbreaks or collapses of SPB populations. This represents the first effective and validated prediction system for outbreaks of a bark beetle species. VL - 802 1 SN - 0363-6224 ER - TY - JOUR T1 - Population Dynamics of Southern Pine Beetle in Forest Landscapes JF - U S Forest Service General Technical Report SRS Y1 - 2011 A1 - Birt, Andrew SP - 91 EP - 108 KW - Dendroctonus frontalis AB - Southern pine beetle (SPB) is an important pest of Southeastern United States pine forests. Periodic regional outbreaks are characterized by localized areas of tree mortality (infestations) surrounded by areas with little or no damage. Ultimately, this spatiotemporal pattern of tree mortality is driven by the dynamics of SPB populations[long dash]more specifically, by rates of survival, reproduction, development, and dispersal. In turn these rates are driven by the interaction between SPB and its hosts, predators, and climate. In this chapter, the relationship between these factors and SPB population ecology are discussed. Particular emphasis is placed on mechanisms that could explain the temporal changes of the population from outbreak to nonoutbreak phases, the dispersal of SPB across a complex forest landscape, and the importance of interpreting the environment using current knowledge of SPB ecology. VL - 140 ER - TY - JOUR T1 - Regional Population Dynamics JF - U S Forest Service General Technical Report SRS Y1 - 2011 A1 - Birt, Andrew SP - 109 EP - 128 KW - Dendroctonus frontalis AB - The population dynamics of the southern pine beetle (SPB) exhibit characteristic fluctuations between relatively long endemic and shorter outbreak periods. Populations exhibit complex and hierarchical spatial structure with beetles and larvae aggregating within individual trees, infestations with multiple infested trees, and regional outbreaks that comprise a large number of spatially distinct infestations. Every year at least some part of the Southern United States experiences outbreaks, and the large and unpredictable timber losses associated with these make the SPB the most important pest of southern tbrests. This chapter reviews the mechanisms that may drive SPB populations at a regional scale. More specifically, it focuses on the initiation and decline of' outbreaks, the patterns of damage within them, and the utility of this knowledge for managing the SPB. VL - 140 ER - TY - JOUR T1 - Lack of genetic differentiation in aggressive and secondary bark beetles (Coleoptera: Curculionidae, Scolytinae) from Arizona JF - Environmental Entomology Y1 - 2008 A1 - Allender, Christopher J. A1 - Clancy, Karen M. A1 - DeGomez, Tom E. A1 - McMillin, Joel D. A1 - Woolbright, Scott A. A1 - Keim, Paul A1 - Wagner, David M. SP - 817 EP - 824 KW - Dendroctonus brevicomis KW - Dendroctonus frontalis KW - Ips pini AB - Bark beetles (Coleoptera: Curculionidae, Scolytinae) play an important role as disturbance agents in ponderosa pine (Pinus ponderosa Douglas ex Lawson) forests of Arizona. However, from 2001 to 2003, elevated bark beetle activity caused unprecedented levels of ponderosa pine mortality. A better understanding of the population structure of these species will facilitate analysis of their dispersal patterns and improve management strategies. Here, we use fluorescently labeled amplified fragment length polymorphism (fAFLP) analysis to resolve genetic variation among and within sampling locations in northcentral Arizona of Ips pini (Say), Dendroctonus brevicomis LeConte, and D. frontalis Zimmermann. We generated genetic fingerprints for >500 beetle specimens and analyzed genetic diversity. For all species, gene flow estimates among sampling locations were high, and significant population subdivision was not discernible across a large portion of ponderosa pine forests in Arizona. However, a weak relationship was detected with L pini population structure and elevation. Because of the lack of genetic differentiation detected throughout the large study area, our findings suggest these insects are capable of long distance dispersal and exhibit a high degree of gene flow across abroad region. We conclude that our results are consistent with strong dispersal patterns and large population sizes of all three species. VL - 37 SN - 0046-225X ER - TY - JOUR T1 - Why does longleaf pine have low susceptibility to southern pine beetle? JF - Canadian Journal of Forest Research Y1 - 2007 A1 - Martinson, Sharon A1 - Hofstetter, Richard W. A1 - Ayres, Matthew P. SP - 1966 EP - 1977 KW - Dendroctonus frontalis AB - Pine forests throughout the world are subject to disturbance from tree-killing bark beetles, but pine species differ in their susceptibilities. In the southeastern United States, Pinus palustris Mill. suffers far less mortality from the southern pine beetle, Dendroctonus frontalis Zimmermann, than do its sympatric congeners. We tested the commonly invoked hypothesis that P. palustris has relatively low susceptibility because it has higher oleoresin flow than other pines, especially Pinus taeda L. However, seven studies in three states over 6 years refuted the hypothesis that P. palustris and P. taeda differ in their constitutive resin flow or in their capacity to replace resin depleted by either experimental wounding or natural beetle attacks. Additionally, surveys of natural beetle attacks revealed that P. taeda and P. palustris were equally likely to be attacked and killed when they cooccurred in front of growing infestations. Thus, the relative susceptibility of these two species changes with the spatial scale at which they are mixed, and the strong landscape-scale pattern of low mortality in P. palustris is not because individual trees are physiologically less susceptible. Ultimately, the conspicuous differential impact of D. frontalis on P. taeda and P. palustris may be the product of coevolution between tree defenses and beetle behavior. VL - 37 SN - 0045-5067 ER - TY - JOUR T1 - Chromosome numbers of Dendroctonus parallelocollis and D. rhizophagus (Coleoptera: Scolytidae) and new reports of Dendroctonus populations from Mexico and Guatemala JF - Annals of the Entomological Society of America Y1 - 1998 A1 - Zuniga, Gerardo A1 - Cisneros, Ramon A1 - Salinas-Moreno, Yolanda SP - 392 EP - 394 KW - Dendroctonus KW - Dendroctonus adjunctus KW - Dendroctonus approximatus KW - Dendroctonus frontalis KW - Dendroctonus mexicanus KW - Dendroctonus parallelocoris KW - Dendroctonus rhizophagus KW - Dendroctonus valens AB - The male meiotic karyotypic formulae of Dendroctonus parallelocollis Chapuis and D. rhizophagus Thomas & Bright are 13 AA + Xyp. These karyotypes are similar to those from D. valens LeConte (13 AA + Xyp) and D. terebrans Olivier (12 AA + Xyp), a situation that confirms the taxonomic grouping of these species by morphological characteristics and their status as closely related species. The chromosome numbers and the sexual systems of populations of Dendroctonus adjunctus LeConte, D. approximatus Dietz, D. frontalis Zimmermann, D. mexicanus Hopkins, and D. valens agree with what has been published for these species. No geographic variation in the karyotypes, supernumerary chromosomes, or irregular associations were observed in the species examined. VL - 91 SN - 0013-8746 ER - TY - JOUR T1 - Comparative anatomical and histological study of the alimentary canal if the Dendroctonus fontalis (Coleoptera: Scotylidae) complex JF - Annals of the Entomological Society of America Y1 - 2000 A1 - Cisneros, Elba Diaz Ramon A1 - Zuniga, Gerardo SP - 303 EP - 311 KW - Dendroctonus approximatus KW - Dendroctonus brevicomis KW - Dendroctonus frontalis KW - Dendroctonus mexicanus AB - In this study we compared the anatomy and histology of the alimentary canal of Dentroctonus approximatus Dietz, D. mexicanus Hopkins, D. frontalis Zimmermann, and D. brevicomis LeConte. The results show that these species share similar characteristics, and their structural pattern is comparable to that observed in other Dendroctonus species. These 4 species have characteristics not found in other bark beetle genera in the esophagus, crop, proventriculus, and hindgut. The close relationship of the Malpighian tubules to posterior foregut, anterior midgut, and distal hindgut is also different. Additionally, the midgut of the D. frontalis complex species shows a great cellular diversity, which suggests that this region may be involved in pheromone production. VL - 93 SN - 0013-8746 N1 - Zoor13600072553 U1 - 23 ER -