03156nas a2200205   4500008004100000020001400041245009500055210006900150260001000219300001200229490000700241520246000248653002702708100001502735700001802750700002502768700002202793700002302815856011202838       2007                        eng d  a1051-076100aImpact of minimum winter temperatures on the population dynamics of Dendroctonus frontalis0 aImpact of minimum winter temperatures on the population dynamics  cApril  a882-8990 v173 aPredicting 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.10aDendroctonus frontalis1 aTran, Khai1 aYlioja, Tiina1 aBillings, Ronald, F.1 aRegniere, Jacques1 aAyres, Matthew, P.  uhttps://weevil.myspecies.info/impact-minimum-winter-temperatures-population-dynamics-dendroctonus-frontalis02098nas a2200205   4500008004100000020001400041245011300055210006900168260001100237300001400248490000700262520134100269653002701610100003001637700002301667700002201690700002601712700002301738856013101761       2007                        eng d  a0045-506700aDifferential impacts of the southern pine beetle, Dendroctonus frontalis, on Pinus palustris and Pinus taeda0 aDifferential impacts of the southern pine beetle Dendroctonus fr  cAugust  a1427-14370 v373 aPatterns 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.10aDendroctonus frontalis1 aFriedenberg, Nicholas, A.1 aWhited, Brenda, M.1 aSlone, Daniel, H.1 aMartinson, Sharon, J.1 aAyres, Matthew, P.  uhttps://weevil.myspecies.info/differential-impacts-southern-pine-beetle-dendroctonus-frontalis-pinus-palustris-and-pinus-taeda01712nas a2200169   4500008004100000020001400041245010100055210006900156260000900225300001200234490000700246520109200253100003001345700002201375700002301397856012201420       2007                        eng d  a1461-023X00aSynchrony's double edge: transient dynamics and the Allee effect in stage structured populations0 aSynchronys double edge transient dynamics and the Allee effect i  cJuly  a564-5730 v103 aIn populations subject to positive density dependence, individuals can increase their fitness by synchronizing the timing of key life history events. However, phenological synchrony represents a perturbation from a population's stable stage structure and the ensuing transient dynamics create troughs of low abundance that can promote extinction. Using an ecophysiological model of a mass-attacking pest insect, we show that the effect of synchrony on local population persistence depends on population size and adult lifespan. Results are consistent with a strong empirical pattern of increased extinction risk with decreasing initial population size. Mortality factors such as predation on adults can also affect transient dynamics. Throughout the species range, the seasonal niche for persistence increases with the asynchrony of oviposition. Exposure to the Allee effect after establishment may be most likely at northern range limits, where cold winters tend to synchronize spring colonization, suggesting a role for transient dynamics in the determination of species distributions.1 aFriedenberg, Nicholas, A.1 aPowell, James, A.1 aAyres, Matthew, P.  uhttps://weevil.myspecies.info/synchronys-double-edge-transient-dynamics-and-allee-effect-stage-structured-populations02420nas a2200205   4500008004500000020001400045245013300059210006900192260000900261300001200270490000700282520164000289653002701929100003001956700002001986700002502006700002502031700002302056856013502079       2008                        Engldsh    a0046-225X00aTemperature extremes, density dependence, and southern pine beetle (Coleoptera: Curculionidae) population dynamics in east Texas0 aTemperature extremes density dependence and southern pine beetle  cJune  a650-6590 v373 aPrevious 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.10aDendroctonus frontalis1 aFriedenberg, Nicholas, A.1 aSarkar, Sudipta1 aKouchoukos, Nicholas1 aBillings, Ronald, F.1 aAyres, Matthew, P.  uhttps://weevil.myspecies.info/temperature-extremes-density-dependence-and-southern-pine-beetle-coleoptera-curculionidae-population01804nas a2200157   4500008004100000245006000041210005900101260000900160300001000169490000800179520129100187100002301478700002601501700003001527856008901557       2011                        eng d00aSouthern Pine Beetle Ecology: Populations within Stands0 aSouthern Pine Beetle Ecology Populations within Stands  c2011  a75-890 v1403 aPopulations of southern pine beetle (SPB) are typically substructured into local aggregations, each with tens of thousands of individual beetles. These aggregations, known as "spots" because of their appearance during aerial surveys, are the basic unit for the monitoring and management of SPB populations in forested regions. They typically have a maximum lifespan of I year, being born in the spring when dispersing SPB aggregate at points in the forest. Spots that survive to the following spring produce the dispersing beetles that form a new population of spots. SPB epidemics rise and fall with interannual variation in the number of spots within a region. Many spots, especially those that begin small, die an early death by midsummer. Others may grow throughout the summer and into the winter via a self-propagating progression of tree attacks that is critically structured by semiochemicals. Forces that influence the growth of populations within spots strongly influence the dynamic fluctuations in SPB impacts on regional forests. These forces include pine species composition, habitat edges, age and basal area of pine stands, tree defenses, the predator Thanasirnus dubins, interactions with phoretic mites and fungi, climate, and movement of beetles into and out of spots.1 aAyres, Matthew, P.1 aMartinson, Sharon, J.1 aFriedenberg, Nicholas, A.  uhttps://weevil.myspecies.info/southern-pine-beetle-ecology-populations-within-stands01987nas a2200181   4500008004100000020001400041245007600055210006900131260001200200300001400212490000700226520137000233653002701603100002201630700002801652700002301680856010201703       2007                        eng d  a0045-506700aWhy does longleaf pine have low susceptibility to southern pine beetle?0 aWhy does longleaf pine have low susceptibility to southern pine   cOctober  a1966-19770 v373 aPine 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.10aDendroctonus frontalis1 aMartinson, Sharon1 aHofstetter, Richard, W.1 aAyres, Matthew, P.  uhttps://weevil.myspecies.info/why-does-longleaf-pine-have-low-susceptibility-southern-pine-beetle