02354nas a2200193   4500008004100000020001400041245010900055210006900164260000800233300001200241490000700253520165500260100002701915700002201942700002101964700002301985700002602008856012602034       2010                        eng d  a1461-955500aPerformance of the invasive weevil Polydrusus sericeus is influenced by atmospheric CO2 and host species0 aPerformance of the invasive weevil Polydrusus sericeus is influe  cAug  a285-2920 v123 aNatural forest systems constitute a major portion of the world's land area, and are subject to the potentially negative effects of both global climate change and invasion by exotic insects. A suite of invasive weevils has become established in the northern hardwood forests of North America. How these insects will respond to increasing CO2 or O3 is unknown. The present study examined the effects of elevated atmospheric CO2 and O3 on the invasive weevil Polydrusus sericeus Schaller at the Aspen Free Air CO2 Enrichment (FACE) site near Rhinelander, Wisconsin. A performance assay was conducted in the laboratory during the summer of 2007 using mated pairs of P. sericeus fed a combination of aspen, birch and maple foliage. We recorded leaf area consumption, oviposition and adult longevity. We also conducted visual abundance surveys in the field from 2004 to 2007 on aspen and birch at Aspen FACE. Elevated CO2, but not O3, significantly affected P. sericeus performance. Female, but not male, longevity was reduced under elevated CO2. Polydrusus sericeus also produced fewer eggs under elevated CO2 conditions compared with ambient conditions. Adult P. sericeus strongly preferred birch over both aspen and maple, regardless of fumigation treatment. The effects of elevated CO2 on P. sericeus populations at Aspen FACE were minimal, and varied among years and host tree species. Polydrusus sericeus abundance was significantly greater on birch than aspen. Over the long term, elevated CO2 may reduce adult female longevity and fecundity of P. sericeus. Further studies are needed to evaluate how this information may scale to ecosystem impacts.1 aHillstrom, Michael, L.1 aVigue, Leanne, M.1 aCoyle, David, R.1 aRaffa, Kenneth, F.1 aLindroth, Richard, L.  uhttps://weevil.myspecies.info/performance-invasive-weevil-polydrusus-sericeus-influenced-atmospheric-co2-and-host-species02076nas a2200193   4500008004100000020001400041245013500055210006900190260000800259300001400267490000700281520134200288653002401630653002401654100002101678700002501699700002301724856013501747       2010                        eng d  a0046-225X00aLaboratory Performance of Two Polyphagous Invasive Weevils on the Predominant Woody Plant Species of a Northern Hardwood Community0 aLaboratory Performance of Two Polyphagous Invasive Weevils on th  cAug  a1242-12480 v393 aA complex of invasive weevils that consume roots as larvae and foliage as adults have become established in northern hardwood forests in North America. We evaluated adults of the two most prominent species, Phyllobius oblongus and Polydrusus sericeus, for longevity, foliage consumption, and egg production on several putative hosts commonly found in this ecosystem. Adult pairs were monitored in no-choice laboratory assays for the duration of their lifespans on basswood, Tilia americana, ironwood, Ostrya virgimana, sugar maple, Acer saccharum, raspberry, Rubus spp.. or leatherwood, Dirca palustrus Overall, P sericeus lived more than twice as long as P oblongus and lived longer on all hosts. P sericeus consumed more total leaf area than P oblongus on basswood, ironwood, and raspberry, but P oblongus had a higher leaf consumption rate on sugar maple Basswood was a very good host for P sericeus Leatherwood was not a suitable host for either weevil species. The higher longevity and fecundity of P sericeus than P oblongus did not agree with that expected from population data, in that the latter species is substantially more abundant This likely reflects P oblongus' superior performance on sugar maple, the dominant flora in the study area These data provide a basis for estimating the broader impacts of adult weevil feeding.10aPhyllobius oblongus10aPolydrusus sericeus1 aCoyle, David, R.1 aMattson, William, J.1 aRaffa, Kenneth, F.  uhttps://weevil.myspecies.info/laboratory-performance-two-polyphagous-invasive-weevils-predominant-woody-plant-species-northern-har02419nas a2200181   4500008004100000020001400041245014700055210006900202260000800271300001400279490000700293520170900300653002402009100002102033700002502054700002302079856013502102       2010                        eng d  a0046-225X00aHost Plant Phenology Affects Performance of an Invasive Weevil, Phyllobius oblongus (Coleoptera: Curculionidae), in a Northern Hardwood Forest0 aHost Plant Phenology Affects Performance of an Invasive Weevil P  cOct  a1539-15440 v393 aWe investigated how host plant phenology and plant species affected longevity, reproduction, and feeding behavior of an invasive weevil. Phyllobius oblongus L. (Coleoptera: Curculionidae) is common in northern hardwood forests of the Great Lakes Region. Adults emerge in spring, feed on foliage of woody understory plants, and oviposit in the soil. Preliminary data indicate that adults often feed on sugar maple, Acer saccharum Marshall, foliage early in the season, then feed on other species such as raspberry, Rams spp. Whether this behavior reflects temporal changes in the quality of A. saccharum tissue or merely subsequent availability of later-season plants is unknown. We tested adult P. oblongus in laboratory assays using young (newly flushed) sugar maple foliage, old (2-3 wk postflush) sugar maple foliage, and raspberry foliage. Raspberry has indeterminate growth, thus always has young foliage available for herbivores. Survival, oviposition, and leaf consumption were recorded. In performance assays under no-choice conditions, mated pairs were provided one type of host foliage for the duration of their lives. In behavioral choice tests, all three host plants were provided simultaneously and leaf area consumption was compared. Adults survived longer on and consumed greater amounts of young maple and raspberry foliage than old maple foliage. P. oblongus preferred young maple foliage to old maple foliage early in the season, however, later in the growing season weevils showed less pronounced feeding preferences. These results suggest how leaf phenology, plant species composition, and feeding plasticity in host utilization may interact to affect P. oblongus population dynamics.10aPhyllobius oblongus1 aCoyle, David, R.1 aJordan, Michelle, S.1 aRaffa, Kenneth, F.  uhttps://weevil.myspecies.info/host-plant-phenology-affects-performance-invasive-weevil-phyllobius-oblongus-coleoptera-curculionida03533nas a2200205   4500008004100000020001400041245017700055210006900232260001500301300001200316490000800328520274700336653000803083100002203091700001303113700001903126700002503145700002303170856013403193       2010                        eng d  a0378-112700aPredisposition to bark beetle attack by root herbivores and associated pathogens: roles in forest decline, gap formation, and persistence of endemic bark beetle populations0 aPredisposition to bark beetle attack by root herbivores and asso  cJanuary 25  a374-3820 v2593 aBark beetles are largely known for their ability to undergo intermittent population eruptions that transform entire landscapes and pose significant economic hardships. However, most species do not undergo outbreaks, and eruptive species usually exert only minor disturbances. Understanding the dynamics of tree-killing noneruptive species can provide insights into how beetles persist at low densities, and how some spatiotemporal patterns of host predisposition may more likely favor breaching eruptive thresholds than others. Elucidating mechanisms behind low-density populations is challenging, however, due to the requirement of long-term monitoring and high degrees of spatial and temporal covariance. We censused more than 2700 trees annually over 7 years, and at the end of 17 years, in a mature red pine plantation. Trees were measured for the presence of bark beetles and wood borers that breed within the primary stem, root weevils that breed in root collars, and bark beetles that breed in basal stems. We quantify the sequence of events that drive this decline syndrome, with the primary emergent pattern being an interaction between below- and above-ground herbivores and their fungal symbionts. This interaction results in an expanding forest gap, with subsequent colonization by early-successional vegetation. Spatial position strongly affects the likelihood of tree mortality. A red pine is initially very likely to avoid attack by tree-killing Ips beetles, but attack becomes increasingly likely as the belowground complex spreads to neighboring trees and eventually make trees susceptible. This system is largely internally driven, as there are strong gap edge, but not stand-edge, effects. Additional stressors, such as drought, can provide an intermittent source of susceptible trees to Ips beetles, and elevated temperature slightly accentuates this effect. New gaps can arise from such trees as they subsequently become epicenters for the full complex of organisms associated with this decline, but this is not common. As Ips populations rise, there is some element of positive feedback, in that the proportion of killed trees that were not first colonized by root organisms increases. This positive feedback is very weak, however, and we propose the slope between beetle population density and reliance on host stress as a quantitative distinction along a gradient from noneruptive through eruptive species. Almost all trees colonized by Ips were subsequently colonized by wood borers, likely a source of negative feedback. We discuss implications to our overall understanding of cross-scale interactions, between-guild interactions, forest declines, and eruptive thresholds. (C) 2009 Elsevier B.V. All rights reserved.10aIps1 aAukema, Brian, H.1 aZhu, Jun1 aMoller, Jesper1 aRasmussen, Jakob, G.1 aRaffa, Kenneth, F.  uhttps://weevil.myspecies.info/predisposition-bark-beetle-attack-root-herbivores-and-associated-pathogens-roles-forest-decline-gap02401nas a2200181   4500008004100000020001400041245008400055210006900139260000800208300001200216490000700228520178600235100002202021700002302043700002402066700002302090856010602113       2010                        eng d  a0046-225X00aVariation in Complex Semiochemical Signals Arising From Insects and Host Plants0 aVariation in Complex Semiochemical Signals Arising From Insects   cJun  a874-8820 v393 aChemical communication by many insect species involves complex signals of both insect and plant origin. Much attention has been focused on the behavioral activities of these components but less on their sources of variation, despite implications for evolutionary theory and pest management. We studied variation in chemical signaling at host, tree-within-host, and beetle-on-tree scales using tunneling male pine engravers (Ips pini (Say)) on jack, Pinus banksiana Lamb, red, P. resinosa Aiton, and white, P. strobus L. pines. Pine engravers are distributed transcontinentally, and stereoisomeric ratios of their principal pheromone component ipsdienol varies regionally. Linear mixed-effects models were used to examine variation in monoterpene and pheromone volatile profiles, determined by gas chromatography. Phloem from white pine had the greatest concentration of monoterpenes, although insects tunneling in white pine produced the smallest ratios of monoterpenes to pheromones (1:2) in their volatile plumes relative to jack and red pine (1:1). Beetle-to-beetle variation in plume composition was [approximately equal]2-9 times greater than the inter-tree variation within a tree species. The stereoisomeric ratio of ipsdienol was highly consistent within the pheromone component of the plume. The little variation present existed almost entirely at the level of the insects. Within the pheromone component of the plume in a given host species, there was up to 13 times more beetle-to-beetle than tree-to-tree variation. This magnitude was almost double the magnitudes of the ratios among components within the entire plumes. Implications to the behavioral ecology of bark beetle communication, such as potential strategies of cheating and predator avoidance, are discussed.1 aAukema, Brian, H.1 aPowell, Jaimie, S.1 aClayton, Murray, K.1 aRaffa, Kenneth, F.  uhttps://weevil.myspecies.info/variation-complex-semiochemical-signals-arising-insects-and-host-plants02286nas a2200205   4500008004100000020001400041245012000055210006900175260001000244300001200254490000700266520153400273653002401807100002101831700002201852700002401874700002401898700002301922856013501945       2010                        eng d  a0046-225X00aGeographic Variation in Bacterial Communities Associated With the Red Turpentine Beetle (Coleoptera: Curculionidae)0 aGeographic Variation in Bacterial Communities Associated With th  cApril  a406-4140 v393 aBacterial communities are known to play important roles in insect life histories, yet their consistency or variation across populations is poorly understood. Bacteria associated with the bark beetle Dendroctonus valens Le Conte from eight populations, ranging from Wisconsin to Oregon, were evaluated and compared. We used the culture-independent technique of denaturing gradient gel electrophoresis to visualize bacterial diversity, or individual operational taxonomic units (Os), from individual beetles. One-way analysis of similarities was used to test for differences of bacterial communities between sites. Analysis of community profiles showed that individual beetles on average contained 10 OTUs, with frequency of association from 2 to 100% of beetles. OTU sequences most closely matched [beta]- and [gamma]-proteobacteria, and one each matched Bacilli and Actinobacteria. Several OTUs were particularly abundant, most notably an Actinobacterium from 100% and two Proteobacteria from 60% of beetles sampled. Some OTUs were similar to previously described bacteria with known biochemical capabilities and ecological functions, suggesting that some bacterial associates of D. valens may contribute to its ability to exploit a resource low in nutrients and high in defensive compounds. There were significant differences of bacterial communities between sites. The strength of these differences was positively correlated with distance between sites, although additional unexplained factors also contribute to the variation.10aDendroctonus valens1 aAdams, Aaron, S.1 aAdams, Sandye, M.1 aCurrie, Cameron, R.1 aGillette, Nancy, E.1 aRaffa, Kenneth, F.  uhttps://weevil.myspecies.info/geographic-variation-bacterial-communities-associated-red-turpentine-beetle-coleoptera-curculionidae