02203nas a2200193   4500008004100000020001400041245017100055210006900226260000800295300001400303490000800317520146200325653001701787653000801804100002001812700002301832700001901855856013501874       2010                        eng d  a0022-049300aImpacts of Silvicultural Thinning Treatments on Beetle Trap Captures and Tree Attacks During Low Bark Beetle Populations in Ponderosa Pine Forests of Northern Arizona0 aImpacts of Silvicultural Thinning Treatments on Beetle Trap Capt  cOct  a1693-17030 v1033 aOur research used a combination of passive traps, funnel traps with lures, baited trees, and surveys of long-term thinning plots to assess the impacts of different levels of stand basal area (BA) on bark beetle tree attack and on trap captures of Ips spp., Dendroctonus spp., and their predators. The study occurred at two sites in ponderosa pine, Pinus ponderosa Dough. ex Laws., forests, from 2004 to 2007 during low bark beetle populations. Residual stand BA ranged from 9.0 to 37.0 m2/ha. More predators and bark beetles were collected in passive traps in stands of lower BA than in stands of higher BA; however, significance varied by species and site, and total number of beetles collected was low. Height of the clear panel passive traps affected trap catches for some species at some sites and years. When pheromone lures were used with funnel traps (Ips pini (Say) lure: lanierone, +03/-97 ipsdienol), we found no significant difference in trap catches among basal area treatments for bark beetles and their predators. Similarly, when trees were baited (Dendroctonus brevicomis LeConte lure: myrcene, exo-brevicomin and frontalin), we found no significant difference for days to first bark beetle attack. Surveys of long-term thinning treatments found evidence of bark beetle attacks only in unthinned plots ([approximately equal]37 m2/ha basal area). We discuss our results in terms of management implications for bark beetle trapping and control.10aDendroctonus10aIps1 aGaylord, M., L.1 aHofstetter, R., W.1 aWagner, M., R.  uhttps://weevil.myspecies.info/impacts-silvicultural-thinning-treatments-beetle-trap-captures-and-tree-attacks-during-low-bark-beet03689nas a2200241   4500008004100000020001400041245004100055210004100096260000800137300001200145490000700157520304700164653000803211100002403219700002503243700001303268700001703281700002203298700002303320700001603343700002003359856006803379       2010                        eng d  a0965-174800aPheromone production in bark beetles0 aPheromone production in bark beetles  cOct  a699-7120 v403 aThe first aggregation Pheromone components from bark beetles were identified in 1966 as a mixture of ipsdienol, ipsenol and verbenol. Since then, a number of additional components have been identified as both aggregation and anti-aggregation pheromones, with many of them being monoterpenoids or derived from monoterpenoids. The structural similarity between the major pheromone components of bark beetles and the monoterpenes found in the host trees, along with the association of monoterpenoid production with plant tissue, led to the paradigm that most if not all bark beetle pheromone components were derived from host tree precursors, often with a simple hydroxylation producing the pheromone. In the 1990s there was a paradigm shift as evidence for de novo biosynthesis of pheromone components began to accumulate, and it is now recognized that most bark beetle monoterpenoid aggregation pheromone components are biosynthesized de novo. The bark beetle aggregation pheromones are released from the frass, which is consistent with the isoprenoid aggregation pheromones, including ipsdienol, ipsenol and frontalin, being produced in midgut tissue. It appears that exo-brevocomin is produced de novo in fat body tissue, and that verbenol, verbenone and verbenene are produced from dietary cc-pinene in fat body tissue. Combined biochemical, molecular and functional genomics studies in Ips pini yielded the discovery and characterization of the enzymes that convert mevalonate pathway intermediates to pheromone components, including a novel bifunctional geranyl diphosphate synthase/myrcene synthase, a cytochrome P450 that hydroxylates myrcene to ipsdienol, and an oxidoreductase that interconverts ipsdienol and ipsdienone to achieve the appropriate stereochemistry of ipsdienol for pheromonal activity. Furthermore, the regulation of these genes and their corresponding enzymes proved complex and diverse in different species. Mevalonate pathway genes in pheromone producing male I. pini have much higher basal levels than in females, and feeding induces their expression. In I. dupIicatus and I. pini, juvenile hormone III (JH III) induces pheromone production in the absence of feeding, whereas in I. paraconfusus and I. confusus, topically applied JH III does not induce pheromone production. In all four species, feeding induces pheromone production. While many of the details of pheromone production, including the site of synthesis, pathways and knowledge of the enzymes involved are known for Ips, less is known about pheromone production in Dendroctonus. Functional genomics studies are under way in D. ponderosae, which should rapidly increase our understanding of pheromone production in this genus. This chapter presents a historical development of what is known about pheromone production in bark beetles, emphasizes the genomic and post-genomic work in I. pini and points out areas where research is needed to obtain a more complete understanding of pheromone production. [copyright]2010 Elsevier Ltd. All rights reserved.10aIps1 aBlomquist, Gary, J.1 aFigueroa-Teran, Rubi1 aAw, Mory1 aSong, Minmin1 aGorzalski, Andrew1 aAbbott, Nicole, L.1 aChang, Eric1 aTittiger, Claus  uhttps://weevil.myspecies.info/pheromone-production-bark-beetles03533nas 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-gap