host preference and attack pattern of dendroctonus rhizophagus (coleoptera: curculionidae: scolytinae): a bark beetle specialist on pine regeneration.pine seedlings and saplings are seldom attacked by bark beetles of the genus dendroctonus. however, dendroctonus rhizophagus (coleoptera: curculionidae: scolytinae) thomas and bright specifically attacks pine seedlings and causes conspicuous mortality in naturally regenerated stands in the sierra madre occidental, northern mexico. we evaluated the host preference and attack of d. rhizophagus under field conditions. we tried to establish any relationship between tree growth or host size and the n ...200919689900
gut-associated bacteria throughout the life cycle of the bark beetle dendroctonus rhizophagus thomas and bright (curculionidae: scolytinae) and their cellulolytic activities.dendroctonus rhizophagus thomas and bright (curculionidae: scolytinae) is an endemic economically important insect of the sierra madre occidental in mexico. this bark beetle has an atypical behavior within the genus because just one beetle couple colonizes and kills seedlings and young trees of 11 pine species. in this work, the bacteria associated with the dendroctonus rhizophagus gut were analyzed by culture-dependent and culture-independent methods. analysis of 16s rrna sequences amplified di ...201222234511
degradation capacities of bacteria and yeasts isolated from the gut of dendroctonus rhizophagus (curculionidae: scolytinae).bark beetles (curculionidae: scolytinae) feed on the xylem and phloem of their host, which are composed of structural carbohydrates and organic compounds that are not easily degraded by the insects. some of these compounds might be hydrolyzed by digestive enzymes produced by microbes present in the gut of these insects. in this study, we evaluated the enzymatic capacity of bacteria (acinetobacter lwoffii, arthrobacter sp., pseudomonas putida, pseudomonas azotoformans, and rahnella sp.) and yeast ...201727544667
electrophysiological and behavioral responses of the bark beetle dendroctonus rhizophagus to volatiles from host pines and conspecifics.the bark beetle dendroctonus rhizophagus is endemic to northwestern mexico where it kills immature pines < 3 m tall. we report the first investigation of the chemical ecology of this pest of forest regeneration. we used gc-ead to assess olfactory sensitivity of this species to volatile compounds from: resin of a major host, pinus arizonica; mid/hindguts of single, gallery-initiating females; and mate-paired males within galleries of attacked host trees in the field. antennae of both sexes respon ...201222544334
comparison of orthologous cytochrome p450 genes relative expression patterns in the bark beetles dendroctonus rhizophagus and dendroctonus valens (curculionidae: scolytinae) during host colonization.bark beetles of the genus dendroctonus are important components of coniferous forests. during host colonization, they must overcome the chemical defences of their host trees, which are metabolized by cytochrome p450 (cyp or p450) enzymes to compounds that are readily excreted. in this study, we report the relative expression (quantitative real-time pcr) of four orthologous cytochrome p450 genes (cyp6bw5, cyp6dg1, cyp6dj2 and cyp9z20) in dendroctonus rhizophagus and dendroctonus valens forced to ...201526537737
cytochrome p450 complement (cypome) of candida oregonensis, a gut-associated yeast of bark beetle, dendroctonus rhizophagus.bark beetles (curculionidae: scolytinae) and associated microorganisms must overcome a complex tree's defence system, which includes toxic monoterpenes, to successfully complete their life cycle. a number of studies have suggested these microorganisms could have ecological roles related with the nutrition, detoxification, and semiochemical production. in particular, in filamentous fungi symbionts, cytochrome p450 (cyp) have been involved with terpenoid detoxification and biotransformation proces ...201627567714
isolation and expression of cytochrome p450 genes in the antennae and gut of pine beetle dendroctonus rhizophagus (curculionidae: scolytinae) following exposure to host monoterpenes.bark beetles oxidize the defensive monoterpenes of their host trees both to detoxify them and convert them into components of their pheromone system. this oxidation is catalyzed by cytochrome p450 enzymes and occurs in different tissues of the insect, including the gut (i.e., the site where the beetle's pheromones are produced and accumulated) and the antennae (i.e., the olfactory organs used for perception of airborne defensive monoterpenes as well as other host-associated compounds and pheromo ...201223262344
factors influencing the geographical distribution of dendroctonus rhizophagus (coleoptera: curculionidae: scolytinae) in the sierra madre occidental, méxico.the bark beetle, dendroctonus rhizophagus thomas & bright, is endemic to the sierra madre occidental (smoc) in méxico. this bark beetle is a major pest of the seedlings and young saplings of several pine species that are of prime importance to the nation's forest industry. despite the significance of this bark beetle as a pest, its biology, ecology, and distribution are poorly known. three predictive modeling approaches were used as a first approximation to identify bioclimatic variables related ...201122251632
nitrogen-fixing and uricolytic bacteria associated with the gut of dendroctonus rhizophagus and dendroctonus valens (curculionidae: scolytinae).the bark beetles of the genus dendroctonus feed on phloem that is a nitrogen-limited source. nitrogen fixation and nitrogen recycling may compensate or alleviate such a limitation, and beetle-associated bacteria capable of such processes were identified. raoultella terrigena, a diazotrophic bacteria present in the gut of dendroctonus rhizophagus and d. valens, exhibited high acetylene reduction activity in vitro with different carbon sources, and its nifh and nifd genes were sequenced. bacteria ...201323525792
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