@article {13313,
	title = {Attraction of the Redbay Ambrosia Beetle, Xyleborus glabratus, to Avocado, Lychee, and Essential Oil Lures},
	journal = {Journal of Chemical Ecology},
	volume = {37},
	number = {9},
	year = {2011},
	month = {Sep},
	pages = {932-942},
	abstract = {The redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is an exotic wood-boring insect that vectors the mycopathogen responsible for laurel wilt, a lethal vascular disease of trees in the Lauraceae. High mortality has occurred in native Persea species in the southeastern U. S., and the vector-pathogen complex poses an imminent threat to the production of commercial avocado, P. americana, in south Florida. There is a critical need for effective attractants to detect, monitor, and control this invasive pest. This study combined field tests and laboratory bioassays to evaluate the response of female X. glabratus to host-based volatiles from wood of avocado (cultivars of West Indian, Guatemalan, and Mexican races); from wood of lychee (Litchi chinensis, a presumed non-host that is high in the sesquiterpene [alpha]-copaene, a putative attractant); and to commercial lures containing manuka and phoebe oils, two reported attractive baits. Volatile collections and GC-MS analyses were performed to quantify the sesquiterpene content of test substrates. In the field, traps baited with lychee wood captured more beetles than those with wood from avocado cultivars; traps baited with phoebe oil lures captured more beetles than those with manuka oil lures (the current monitoring tool). In field and laboratory tests, X. glabratus did not show a preference among avocado races in either attraction or host acceptance ( initiation of boring). In choice tests, lychee was more attractive than avocado initially, but a higher percentage of beetles bored into avocado, suggesting that lychee emits more powerful olfactory/visual cues, but that avocado contains more of the secondary cues necessary for host recognition. Emissions of [alpha]-copaene, [beta]-caryophyllene, and [alpha]-humulene were correlated with field captures, and lychee wood may be a source of additional semiochemicals for X. glabratus.},
	keywords = {Xyleborus glabratus},
	isbn = {0098-0331},
	author = {Kendra, Paul E. and Montgomery, Wayne S. and Niogret, Jerome and Pena, Jorge E. and Capinera, John L. and Brar, Gurpreet and Epsky, Nancy D. and Heath, Robert R.}
}
@article {13066,
	title = {Iridoid glycoside variation in the invasive plant dalmatian toadflax, Linaria dalmatica (Plantaginaceae), and sequestration by the biological control agent, Calophasia lunula},
	journal = {Journal of Chemical Ecology},
	volume = {36},
	number = {1},
	year = {2010},
	month = {Jan},
	pages = {70-79},
	abstract = {Invasive plant species can have significant ecological and economic impacts. Although numerous hypotheses highlight the importance of the chemical defenses of invasive plant species, the chemical ecology of many invasive plants has not yet been investigated. In this study, we provide the first quantitative investigation of variation in iridoid glycoside concentrations of the invasive plant Dalmatian toadflax (Linaria dalmatica). We examined variation in chemical defenses at three levels: (1) variation within and among populations; (2) variation due to phenology and/or seasonal differences; and (3) variation among plant parts (leaves, flowers, and stems). Further, we examined two biological control agents introduced to control L. dalmatica for the ability to sequester iridoid glycosides from this invasive plant. Results indicate that L. dalmatica plants can contain high concentrations of iridoid glycosides (up to 17.4\% dry weight of leaves; mean = 6.28 [plus or minus] 0.5 SE). We found significant variation in iridoid glycoside concentrations both within and among plant populations, over the course of the growing season, and among plant parts. We also found that one biological control agent, Calophasia lunula (Lepidoptera: Noctuidae), was capable of sequestering antirrhinoside, an iridoid glycoside found in L. dalmatica, at levels ranging from 2.7 to 7.5\% dry weight. A second biological control agent, Mecinus janthinus (Coleoptera: Curculionidae), a stem-mining weevil, did not sequester iridoid glycosides. The demonstrated variation in L. dalmatica chemical defenses may have implications for understanding variation in the degree of invasiveness of different populations as well as variation in the efficacy of biological control efforts.},
	keywords = {Mecinus janthinus},
	isbn = {0098-0331},
	author = {Jamieson, Mary A. and Bowers, M. Deane}
}
@article {12660,
	title = {The Scent of a Partner: Ambrosia Beetles Are Attracted to Volatiles from Their Fungal Symbionts},
	journal = {Journal of Chemical Ecology},
	volume = {37},
	number = {12},
	year = {2011},
	month = {December},
	pages = {1374-1377},
	abstract = {Invasive fungus-growing ambrosia beetles are an emerging threat to forest ecosystems and fruit industries, but management tools are lacking. Here we explored the potential of beetle symbionts-ambrosia fungi-as a source of attractants. Our focus was the redbay ambrosia beetle, Xyleborus glabratus, and its symbiotic fungus, Raffaelea lauricola, which are devastating lauraceous hosts in the southeastern United States. We also tested three additional co-occurring beetle species and their symbionts. Each beetle species was consistently attracted to the odors of its symbiotic fungal species, occasionally also to symbionts of other species, but never to non-symbiotic Trichoderma. We further confirmed attraction to ethanol (positive control) in some species. Thus, ambrosia fungi produce volatiles attractive to their vector beetles, which may have potential as novel lures for ambrosia beetle management.},
	keywords = {Xyleborus glabratus},
	isbn = {0098-0331},
	author = {Huler, Jiri and Mann, Rajinder and Stelinski, Lukasz L.}
}
@article {11272,
	title = {Aggregation pheromones of two geographical isolates of the New Guinea sugarcane weevil, Rhabdoscelus obscurus},
	journal = {Journal of Chemical Ecology},
	volume = {26},
	number = {12},
	year = {2000},
	note = {Times Cited: 11},
	pages = {2763-2780},
	abstract = {The aggregation pheromones were studied from two geographical isolates (Hakalau, Hawaii, and Silkwood, Queensland, Australia) of the New Guinea sugarcane weevil, Rhabdoscelus obscurus. Coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric (MS) analyses of Porapak Q volatile extract from male and from female Hawaiian R. obscurus revealed a single EAD-active, male-specific candidate pheromone, which was identified as 2-methyl-4-octanol (1). Corresponding volatile analyses from male and from female Australian R. obscurus consistently revealed three EAD-active, male-specific candidate pheromone components that were identified as 1, (E2)-6-methyl-2-hepten-4-ol (rhynchophorol) (2), and 2-methyl-4-heptanol (3). In field experiment 1 in Hakalau, Hawaii, traps baited with a stereoisomeric mixture of synthetic 1 (3 mg/day) plus sugarcane captured more weevils than did traps baited with 1 or sugarcane alone or no bait, indicating that 1 is the pheromone of the Hawaiian R. obscurus population. In field experiment 2, conducted in Silkwood, Australia. traps baited with stereoisomeric mixtures of synthetic 1, 2. and 3 (3 mg/day each) plus sugarcane caught more weevils than did unbaited traps or traps baited with 1, 2, and 3 or sugarcane. Testing candidate pheromone components 1, 2, and 3 in experiments 2-5 in all possible binary, ternary, and quaternary combinations with sugarcane. indicated that 1 and 2 in combination, but not singly, are pheromone components of the Australian R. obscurus population. Weevils from several locations in Australia and Hawaii could not be differentiated using traditional morphological characters or ultrastructural comparisons with scanning electron microscopy (SEM). However, comparisons of mtDNA sequences (cytochrome oxidase I: regions 11 to M4; 201 base pairs) revealed 5.5\% variation between the Hawaiian (N = 2) and the Australian (N = 4) samples. There was no intrapopulation variation in sequence data from the weevils from Hawaii versus Australia, suggesting that they are sibling species.},
	isbn = {0098-0331},
	author = {Giblin-Davis, R. M. and Gries, R. and Crespi, B. and Robertson, L. N. and Hara, A. H. and Gries, G. and Charles W. O{\textquoteright}Brien and Pierce, H. D.}
}
@article {11257,
	title = {Behavioral responses of adult Sitophilus granarius to individual cereal volatiles},
	journal = {Journal of Chemical Ecology},
	volume = {34},
	number = {4},
	year = {2008},
	month = {April},
	pages = {523-529},
	type = {Article},
	abstract = {The antennae of Sitophilus granarius (L.) (Coleoptera: Curculionidae) adults detect a wide variety of compounds in the odor blend of various cereal grains (Germinara et al., Tec. Molit., 53:27-34, 2002). In the present study, we looked at the behavioral responses of the granary weevil to 20 of these individual volatiles (aliphatic alcohols, aldehydes, ketones, and aromatics) in a two-choice pitfall olfactometer, using the aggregation pheromone and propionic acid as the attractant and repellent controls, respectively. Five doses, ranging from 1 [mu]g to 1 mg, of each compound were tested. At least one concentration of eight compounds attracted beetles but required doses 1,000- to 5,000-fold higher than the concentration of aggregation pheromone to elicit a response. Three compounds, while attractive at lower concentrations, acted as repellents at higher doses. Twelve compounds were repellent at concentrations similar to the quantity of propionic acid that significantly repelled beetles. The data show that granary weevil adults have the ability to respond behaviorally to a wide range of cereal volatiles and that responses may change as a function of concentration. The results suggest that host finding behavior of weevils will depend on the balance of positive and negative volatile stimuli from grain as the relative concentrations of volatiles may change during storage. An understanding of how the weevils respond to such changes could be useful for the development of effective integrated pest management strategies.},
	keywords = {Sitophilus granarius},
	isbn = {0098-0331},
	author = {Germinara, Giacinto S. and De Cristofaro, Antonio and Rotundo, Giuseppe}
}
@article {11131,
	title = {3-pentanol: a new attractant present in volatile emissions from the ambrosia beetle, Megaplatypus mutatus},
	journal = {Journal of Chemical Ecology},
	volume = {34},
	number = {11},
	year = {2008},
	month = {November},
	pages = {1446-1451},
	type = {Article},
	abstract = {Megaplatypus mutatus (=Platypus mutatus) (Coleoptera: Platypodidae) is an ambrosia beetle that is native to South America. It attacks only standing live trees and causes severe stem breakage and death in commercial poplar (Populus) plantations. Previous work showed that male M. mutatus emits a sex pheromone composed mainly of (+)-sulcatol and sulcatone. We collected male volatile emissions during the hours of maximum emergence by using a specific polar microextraction phase; analyzed the extract by GC-MS; and tested the biological activity of selected compounds in the extract with a walking behavioral assay. Female M. mutatus emerged primarily between 7 and 11 h. In the chemical analyses of volatiles, a third compound, 3-pentanol, was identified in a small percentage of samples. Walking behavioral bioassays with video image analysis showed that at the doses tested, 3-pentanol elicited an attractive response from females.},
	keywords = {Megaplatypus mutatus},
	isbn = {0098-0331},
	author = {Gatti Liguori, Pablo and Zerba, Eduardo and Alzogaray, Raul A. and Gonzalez Audino, Paola}
}
@article {11089,
	title = {Application of semiochemicals to assess the biodiversity of subcortical insects following an ecosystem disturbance in a sub-boreal forest},
	journal = {Journal of Chemical Ecology},
	volume = {35},
	number = {12},
	year = {2009},
	month = {December},
	pages = {1384-1410},
	abstract = {From 2000 through 2003 we used semiochemical-baited traps in northeastern Minnesota, USA, to assess changes in assemblages of subcortical forest insects after a catastrophic wind storm in 1999 and subsequent (1999-2000) fuel-reduction activities (salvage-logging and prescribed-burning). We determined the regional efficacy of fifteen semiochemical blends (pheromones and kairomones) as attractants for target and non-target subcortical insect species (Coleoptera: Anthribidae, Buprestidae, Cerambycidae, Cleridae, Cucujidae, Curculionidae, Histeridae, Nemonychidae, Salpingidae, Scolytidae, Tenebrionidae, and Hymenoptera: Siricidae). During the four summers, we trapped 86,471 subcortical insects (143 species) in baited and unbaited Lindgren funnel traps, and 500 beetles (44 species) in baited and unbaited pitfall traps. We report 23 new state collection records of subcortical insects from Minnesota. Trap catches of subcortical insects were greatest in the wind-disturbed areas 2 years after the event, and declined thereafter. Similar trends were observed for subcortical insects in the burned areas. Both wind-disturbance and burning increased the subcortical insect species richness and diversity on the landscape. The subcortical insect species compositions of the salvaged and burned forest areas differed from those of the undisturbed and wind-disturbed areas. Trap catches of subcortical insects in response to semiochemical treatments also varied with year of sampling and land-area treatment. The greatest diversity of subcortical beetle species was in traps baited with attractants for the scolytids, Dendroctonus valens ((+)-[alpha]-pinene and (-)-[beta]-pinene) and Dryocoetes spp. (exo-brevicomin and (-)-[alpha]-pinene), perhaps reflecting the generic nature of the baits. The most distinct species compositions were collected in response to the woodborer and Dendroctonus simplex baits, whereas the species compositions in traps with the D. valens and Dryocoetes spp. baits, and the unbaited funnel trap were the most similar. The variation in trap catch with time and across landscapes suggests that the responses of subcortical insects to semiochemicals are more complex than previously appreciated.},
	isbn = {0098-0331},
	author = {Gandhi, Kamal J. K. and Gilmore, Daniel W. and Haack, Robert A. and Katovich, Steven A. and Krauth, Steven J. and Mattson, William J. and Zasada, John C. and Seybold, Steven J.}
}
@article {10908,
	title = {Responses of the Mediterranean pine shoot beetle Tomicus destruens (Wollaston) to pine shoot and bark volatiles},
	journal = {Journal of Chemical Ecology},
	volume = {34},
	number = {9},
	year = {2008},
	month = {September},
	pages = {1162-1169},
	type = {Article},
	abstract = {The pine shoot beetle Tomicus destruens has two dispersal phases per generation. In the first, mature adults move toward trunks of dying pines to lay eggs; in the second, callow adults move toward the shoots of healthy pines for maturation feeding. However, there is no information on the chemical stimuli that govern host selection by T. destruens adults. The aims of this study were: (1) to identify the volatiles released by shoots and bark of stone pine that are behaviorally and electrophysiologically active on T. destruens; (2) to verify which blends and concentrations of such volatiles are differently active on males and females, as well as on callow and mature adults, during the two host search phases (breeding and feeding). A four-arm olfactometer was used to test the behavior of walking T. destruens adults toward various sources of volatiles including fresh shoots and bark, their collected volatiles, and two synthetic blends. For each odor, the behavior of both callow and mature males and females was recorded individually. Shoot and bark extracts were analyzed by coupled gas chromatography and mass spectrometry (GC-MS), and tested by gas chromatography coupled with electroantennography (GC-EAD) on T. destruens males and females. Two blends of two ([alpha]-pinene and [beta]-myrcene; blend A) and three ([alpha]-pinene, [beta]- myrcene, and [alpha]-terpinolene; blend B) synthetic compounds, chosen among those that induce EAD responses and known to be attractive for other bark beetle species, were tested in the olfactometer at five concentrations. Insect behavior was affected by the degree of sexual maturation but not by sex. Callow insects were attracted by shoots and their extracts, while mature individuals by bark and its extracts. Six extracted compounds were active on T. destruens antennae: limonene, (Z)-3-hexen-1-ol and [beta]-caryophyllene, [alpha]-pinene, [beta]-myrcene, and [alpha]-terpinolene. [alpha]-Terpinolene, released only by bark, was active only on mature insects, whereas (Z)-3-hexen-1-ol, released only by shoots, was active only on callows. Males and females showed similar EAD responses. Of the six extracted volatiles, two were attractive for callow adults (blend A) and three for matures (blend B). In both cases, responses were positively correlated with blend concentration, although a repellent effect was noted at the highest concentrations.},
	keywords = {Tomicus destruens},
	isbn = {0098-0331},
	author = {Faccoli, Massimo and Anfora, Gianfranco and Tasin, Marco}
}
@article {10883,
	title = {Antifeedants and feeding stimulants in bark extracts of ten woody non-host species of the pine weevil, Hylobius abietis},
	journal = {Journal of Chemical Ecology},
	volume = {34},
	number = {10},
	year = {2008},
	month = {October},
	pages = {1290-1297},
	type = {Article},
	abstract = {Bark of ten woody species, known to be rejected as a food source by the pine weevil, Hylobius abietis, were sequentially extracted by a Soxhlet apparatus with pentane followed by methanol. Species were alder (Alnus glutinosa), aspen (Populus tremula), beech (Fagus sylvatica), guelder rose (Viburnum opulus), holly (Ilex aquifolium), horse chestnut (Aesculus hippocastanum), lilac (Syringa vulgaris), spindle tree (Evonymus europaeus), walnut (Juglans regia), and yew (Taxus baccata). Bark of each species was collected in southern Scandinavia during the summer. Resulting extracts were tested for antifeedant activity against the pine weevil by a micro-feeding choice assay. At a dose corresponding to that in the bark, methanol extracts from Aesculus, Taxus, Ilex, and Populus were antifeedant active, while pentane extracts of Aesculus, Fagus, Syringa, and Viburnum were stimulatory. Four known antifeedants against H. abietis, the straight-chained carboxylic acids, hexanoic and nonanoic acid (C6 and C9), carvone, and carvacrol were identified by gas chromatography (GC)-mass spectrometry (MS) in several extracts. The major constituents were identified and tested for feeding deterrence. The aromatic compounds benzyl alcohol and 2-phenylethanol are new non-host plant-derived feeding deterrents for the pine weevil. Additionally, two feeding stimulants, [beta]-sitosterol and 5-(hydroxymethyl)-2-furaldehyde, were identified. One active methanol extract of Aesculus bark was sequentially fractionated by liquid chromatography, and major compounds were tentatively identified as branched alcohols and esters of hexanoic acid. Five commercially available hexanoate esters and two commercially available branched alcohols were identified as new active antifeedants. Both stimulatory and inhibiting compounds were found in the same extracts and co-eluted in the same or adjacent fractions. The mix of semiochemicals of opposite activity in each extract or fraction could explain the stimulatory-, inhibitory-, or sometimes neutral activity. Generally, such co-occurrence confounds the isolation of antifeedants.},
	keywords = {Hylobius abietis},
	isbn = {0098-0331},
	author = {Eriksson, Carina and Mansson, Per E. and Sjodin, Kristina and Schlyter, Fredrik}
}
@article {10878,
	title = {Response to host volatiles by native and introduced populations of Dendroctonus valens (Coleoptera: Curculionidae, Scolytinae) in North America and China},
	journal = {Journal of Chemical Ecology},
	volume = {33},
	number = {1},
	year = {2007},
	month = {January},
	pages = {131-146},
	abstract = {Bark beetles (Coleoptera: Curculionidae, Scolytinae) have specialized feeding habits, and commonly colonize only one or a few closely related host genera in their geographical ranges. The red turpentine beetle, Dendroctonus valens LeConte, has a broad geographic distribution in North America and exploits volatile cues from a wide variety of pines in selecting hosts. Semiochemicals have been investigated for D. valens in North America and in its introduced range in China, yielding apparent regional differences in response to various host volatiles. Testing volatiles as attractants for D. valens in its native and introduced ranges provides an opportunity to determine whether geographic separation promotes local adaptation to host compounds and to explore potential behavioral divergence in native and introduced regions. Furthermore, understanding the chemical ecology of host selection facilitates development of semiochemicals for monitoring and controlling bark beetles, especially during the process of expansion into new geographic ranges. We investigated the responses of D. valens to various monoterpenes across a wide range of sites across North America and one site in China, and used the resulting information to develop an optimal lure for monitoring populations of D. valens throughout its Holarctic range. Semiochemicals were selected based on previous work with D. valens: (R)-(+)-[alpha]-pinene, (S)-(-)-[alpha]-pinene, (S)-(-)-[beta]-pinene, (S)-(+)-3-carene, a commercially available lure (1:1:1 ratio of (R)-(+)-[alpha]-pinene:(S)-(-)-[beta]-pinene:(S)-(+)-3-carene), and a blank control. At the release rates used, (+)-3-carene was the most attractive monoterpene tested throughout the native range in North America and introduced range in China, confirming results from Chinese studies. In addition to reporting a more effective lure for D. valens, we present a straightforward statistical procedure for analysis of insect trap count data yielding cells with zero counts, an outcome that is common but makes the estimation of the variance with a Generalized Linear Model unreliable because of the variability/mean count dependency.},
	keywords = {Dendroctonus valens},
	isbn = {0098-0331},
	author = {Erbilgin, N. and Mori, S. R. and Sun, J. H. and Stein, J. D. and Owen, D. R. and Merrill, L. D. and Campos Bolanos, R. and Raffa, K. F. and Mendez Montiel, T. and Wood, D. L. and Gillette, N. E.}
}
@article {10872,
	title = {Acetophenone as an anti-attractant for the western pine beetle, Dendroctonus brevicomis LeConte (Coleoptera: Scolytidae)},
	journal = {Journal of Chemical Ecology},
	volume = {33},
	number = {4},
	year = {2007},
	month = {April},
	pages = {817-823},
	abstract = {Host location and colonization by bark beetles is dependent upon the relative and absolute amounts of attractant and antiattractant compounds available. Many investigations have lead to use of antiattractants for the management of these pests and have been especially focused on verbenone. However, recent studies have identified new antiattractants for several species of bark beetles. We report results of recent investigations of the response of western pine beetle, Dendroctonus brevicomis LeConte, to two recently identified antiattractants, acetophenone, and fenchyl alcohol, with verbenone as a standard of comparison, in northern California. Release of both acetophenone and verbenone resulted in significantly lower trap catches of D. brevicomis in aggregation pheromone-baited traps, while fenchyl alcohol was inactive. Acetophenone was the only antiattractant that did not reduce numbers of the most abundant predator of D. brevicomis, Temnochila chlorodia (Mannerheim), responding to the attractant pheromone of its prey. Aggregation pheromone-baited traps with acetophenone also had the highest predator/prey ratio. Our results suggest that acetophenone may be part of the intra- and interspecific interactions among sympatric species of bark beetles and may have application in their control.},
	keywords = {Dendroctonus brevicomis},
	isbn = {0098-0331},
	author = {Erbilgin, N. and Gillette, N. E. and Mori, S. R. and Stein, J. D. and Owen, D. R. and Wood, D. L.}
}
@article {10611,
	title = {Oleoresin Chemistry Mediates Oviposition Behavior and Fecundity of a Tree-Killing Bark Beetle},
	journal = {Journal of Chemical Ecology},
	volume = {37},
	number = {11},
	year = {2011},
	month = {Nov},
	pages = {1177-1183},
	abstract = {Many herbivores are sensitive to the secondary chemistry of their host plants. However, the influence of pine secondary chemicals (monoterpenes) on bark beetle fitness is poorly understood. We tested the hypothesis that the monoterpene composition of the phloem oleoresin of ponderosa pine, Pinus ponderosa var scopulorum, mediates rates of host acceptance, oviposition behavior, and fecundity of the western pine beetle, Dendroctonus brevicomis. We performed reciprocal rearing experiments, controlling for the monoterpene composition (chemotype) of host material. We tested the effects of two geographically interspersed host chemotypes on beetles with unknown (wild) and known (reared F1) chemical histories. Host chemotype and insect chemical history did not affect rates of acceptance of host material by female beetles. Insect chemical history affected egg gallery construction, and beetles constructed egg galleries that were on average 24.3\% longer when reared in host material that was chemically similar to their natal host material. However, mean egg gallery lengths did not differ between host chemotypes. Insect chemical history also influenced fecundity: F1 beetles produced 52.7\% more offspring on average when reared in host material that was chemically similar to their natal host. Our experiments demonstrate that the chemical history of bark beetles mediates egg gallery construction and fecundity, but not host acceptance. This implicates chemical history as a more important factor than host chemotype in the oviposition behavior and fecundity of D. brevicomis.},
	keywords = {Dendroctonus brevicomis},
	isbn = {0098-0331},
	author = {Davis, Thomas S. and Hofstetter, Richard W.}
}
@article {9847,
	title = {Electrophysiological and Behavioral Responses of the Bark Beetle to Volatiles from Host Pines and Conspecifics},
	journal = {Journal of Chemical Ecology},
	volume = {38},
	number = {5},
	year = {2012},
	month = {May},
	pages = {512-524},
	abstract = {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 responded to monoterpenes [alpha]-pinene, [beta]-pinene and 3-carene as well as to the beetle-derived oxygenated monoterpenes fenchyl alcohol, myrtenal, cis-verbenol, trans-verbenol, verbenone, and myrtenol. These monoterpenes were quantified from pre-emerged D. rhizophagus adults forced to attack host tissue in the laboratory, and from individuals dissected from naturally-attacked hosts at different stages of colonization. In both bioassays, myrtenol and trans-verbenol were the most abundant volatiles, and trans-verbenol was the only one produced in significantly greater quantities by females than males in a naturally-colonized host. Two field experiments were performed to evaluate behavioral responses of D. rhizophagus to antennally-active monoterpenes. Results show that 3-carene was significantly attractive either alone or in a ternary (1:1:1) combination with [alpha]-pinene and [beta]-pinene, whereas neither [alpha]-pinene nor [beta]-pinene alone were attractive. None of the beetle-associated oxygenated monoterpenes enhanced the attractiveness of the ternary mixture of monoterpenes, while verbenone either alone or combined with the other five oxygenated terpenes reduced D. rhizophagus attraction to the ternary mixture. The results suggest that attraction of D. rhizophagus to the host tree P. arizonica is mediated especially by 3-carene. There was no conclusive evidence for an aggregation or sex attractant pheromone.},
	keywords = {Dendroctonus rhizophagus},
	isbn = {0098-0331},
	author = {Cano-Ramirez, Claudia and Armendariz-Toledano, Francisco and Macias-Samano, Jorge E. and Sullivan, Brian T. and Zuniga, Gerardo}
}
@article {9427,
	title = {Structure-activity relationships of phenylpropanoids as antifeedants for the pine weevil Hylobius abietis},
	journal = {Journal of Chemical Ecology},
	volume = {34},
	number = {3},
	year = {2008},
	month = {March},
	pages = {339-352},
	type = {Article},
	abstract = {Ethyl cinnamate has been isolated from the bark of Pinus contorta in the search for antifeedants for the pine weevil, Hylobius abietis. Based on this lead compound, a number of structurally related compounds were synthesized and tested. The usability of the Topliss scheme, a flow diagram previously used in numerous structure-activity relationship (SAR) studies, was evaluated in an attempt to find the most potent antifeedants. The scheme was initially followed stepwise; subsequently, all compounds found in the scheme were compared. In total, 51 phenylpropanoids were tested and analyzed for SARs by using arguments from the field of medicinal chemistry (rational drug design). Individual Hansch parameters based on hydrophobicity, steric, and electronic properties were examined. The effects of position and numbers of substituents on the aromatic ring, the effects of conjugation in the molecules, and the effects of the properties of the parent alcohol part of the esters were also evaluated. It proved difficult to find strong SARs derived from single physicochemical descriptors, but our study led to numerous new, potent, phenylpropanoid antifeedants for the pine weevil. Among the most potent were methyl 3-phenylpropanoates monosubstituted with chloro, fluoro, or methyl groups and the 3,4-dichlorinated methyl 3-phenylpropanoate.},
	keywords = {Hylobius abietis},
	isbn = {0098-0331},
	author = {Bohman, B. and Nordlander, G. and Nordenhem, H. and Sunnerheim, K. and Borg-Karlson, A. K. and Unelius, C. R.}
}
@article {9241,
	title = {Two regulatory mechanisms of monoterpenoid pheromone production in Ips spp. of bark beetles},
	journal = {Journal of Chemical Ecology},
	volume = {35},
	number = {6},
	year = {2009},
	month = {June},
	pages = {689-697},
	abstract = {Bark beetles use aggregation pheromones to coordinate host colonization and mating. These monoterpenoid chemical signals are produced de novo in midgut cells via the mevalonate pathway, and pheromone production is induced when an adult beetle feeds on phloem of a host tree. In Ips pini, juvenile hormone (JH) III influences key regulatory enzymes along the mevalonate pathway that leads to pheromone production. In fact, topically applied JH III is sufficient to stimulate pheromone production in unfed males. In this study, we explore the influence of feeding and JH III treatment on pheromone production in male Ips confusus, the pinyon Ips. We also characterize the influence of feeding and JH III treatment on transcript levels and activity of three key enzymes involved in pheromone biosynthesis: 3-hydroxy-3-methylglutaryl-CoA (HMG) synthase (HMGS), HMG-CoA reductase (HMGR) and geranyl diphosphate synthase (GPPS). We also extend the current understanding of the regulation of pheromone biosynthesis in I. pini, by measuring the influence of feeding and JHIII treatment on enzymatic activity of HMGS and GPPS. Feeding on host phloem alone strongly induces pheromone production in male I. confusus, while JH III treatment has no effect. However, feeding and JH III both significantly up-regulate mRNA levels of key mevalonate pathway genes. Feeding up-regulates these genes to a maximum at 32 h, whereas with JH III-treatment, they are up-regulated at 4, 8, and 16 h, but return near to non-treatment levels at 32 h. Feeding, but not JH III treatment, also increases the activity of all three enzymes in I. confusus, while both feeding or treatment with JH III increase HMGS and GPPS activity in I. pini. Our data suggest that pheromone production in Ips is not uniformly controlled by JH III and feeding may stimulate the release of some other regulatory factor, perhaps a brain hormone, required for pheromone production.},
	keywords = {Ips, Ips pini},
	isbn = {0098-0331},
	author = {Bearfield, Jeremy C. and Henry, Anastasia G. and Tittiger, Claus and Blomquist, Gary J. and Ginzel, Matthew D.}
}
@article {9016,
	title = {Attraction Modulated by Spacing of Pheromone Components and Anti-attractants in a Bark Beetle and a Moth},
	journal = {Journal of Chemical Ecology},
	volume = {37},
	number = {8},
	year = {2011},
	month = {Aug},
	pages = {899-911},
	abstract = {Orientation for insects in olfactory landscapes with high semiochemical diversity may be a challenging task. The partitioning of odor plumes into filaments that are interspersed with pockets of {\textquoteright}clean air{\textquoteright} may help filament discrimination and upwind flight to attractive sources in the face of inhibitory signals. We studied the effect of distance between odor sources on trap catches of the beetle, Ips typographus, and the moth, Spodoptera littoralis. Insects were tested both to spatially separated pheromone components (cis-verbenol and 2-methyl-3-buten-2-ol for Ips; (Z,E)-9,11-tetradecadienyl acetate and (Z,E)-9,12-tetradecadienyl acetate for Spodoptera), and to separated pheromone and anti-attractant sources (non-host volatile (NHV) blend for Ips; (Z)-9-tetradecenyl acetate for Spodoptera). Trap catch data were complemented with simulations of plume structure and plume overlap from two separated sources using a photo ionization detector and soap bubble generators. Trap catches of the beetle and the moth were both affected when odor sources in the respective traps were increasingly separated. However, this effect on trap catch occurred at smaller (roughly by an order of magnitude) odor source separation distances for the moth than for the beetle. This may reflect differences between the respective olfactory systems and central processing. For both species, the changes in trap catches in response to separation of pheromone components occurred at similar spacing distances as for separation of pheromone and anti-attractant sources. Overlap between two simulated plumes depended on distance between the two sources. In addition, the number of detected filaments and their concentration decreased with downwind distance. This implies that the response to separated odor sources in the two species might take place under different olfactory conditions. Deploying multiple sources of anti-attractant around a pheromone trap indicated long-distance (meter scale) effects of NHV on the beetle and a potential use for NHV in forest protection.},
	isbn = {0098-0331},
	author = {Andersson, Martin N. and Binyameen, Muhammad and Sadek, Medhat M. and Schlyter, Fredrik}
}
@article {8958,
	title = {Subterranean Herbivore-induced Volatiles Released by Citrus Roots upon Feeding by Diaprepes abbreviatus Recruit Entomopathogenic Nematodes},
	journal = {Journal of Chemical Ecology},
	volume = {36},
	number = {4},
	year = {2010},
	month = {Apr},
	pages = {361-368},
	abstract = {Herbivore-induced volatile emissions benefit plant hosts by recruiting natural enemies of herbivorous insects. Such tritrophic interactions have been examined thoroughly in the above-ground terrestrial environment. Recently, similar signals have also been described in the subterranean environment, which may be of equal importance for indirect plant defense. The larvae of the root weevil, Diaprepes abbreviates, are a serious pest of citrus. Infestations can be controlled by the use of entomopathogenic nematodes, yet the interactions between the plant, insect and nematode are poorly understood and remain unpredictable. In bioassays that used a root zone six-arm olfactometer, citrus roots ({\textquoteright}Swingle citrumelo{\textquoteright} rootstock) recruited significantly more entomopathogenic nematodes (Steinernema diaprepesi) when infested with root weevil larvae than non-infested roots. Infested plants were more attractive to nematodes than larvae alone. Roots damaged by weevil larvae attracted more nematodes than mechanically damaged roots and sand controls. By dynamic in situ collection and GC-MS analysis of volatiles from soil, we determined that four major terpene compounds were produced by infested plant roots that were not found in samples from non-infested roots or soil that contained only larvae. Solvent extracts of weevil-infested roots attracted more nematodes than extracts of non-infested roots in a two choice sand-column bioassay. These findings suggest that Swingle citrus roots release induced volatiles as an indirect defense in response to herbivore feeding, and that some of these induced volatiles function as attractants for entomopathogenic nematodes.},
	isbn = {0098-0331},
	author = {Ali, Jared G. and Alborn, Hans T. and Stelinski, Lukasz L.}
}
@article {8899,
	title = {Responses of Bark Beetle-Associated Bacteria to Host Monoterpenes and Their Relationship to Insect Life Histories},
	journal = {Journal of Chemical Ecology},
	volume = {37},
	number = {8},
	year = {2011},
	month = {Aug},
	pages = {808-817},
	abstract = {Bark beetles that colonize living conifers and their microbial associates encounter constitutive and induced chemical defenses of their host. Monoterpene hydrocarbons comprise a major component of these allelochemicals, and many are antibiotic to insects, fungi, and bacteria. Some bark beetle species exhaust these defenses by killing their host through mass attacks mediated by aggregation pheromones. Others lack adult aggregation pheromones and do not engage in pheromone-mediated mass attacks, but rather have the ability to complete development within live hosts. In the former species, the larvae develop in tissue largely depleted of host terpenes, whereas in the latter exposure to these compounds persists throughout development. A substantial literature exists on how monoterpenes affect bark beetles and their associated fungi, but little is known of how they affect bacteria, which in turn can influence beetle performance in various manners. We tested several bacteria from two bark beetle species for their ability to grow in the presence of a diversity of host monoterpenes. Bacteria were isolated from the mountain pine beetle, Dendroctonus ponderosae Hopkins, which typically kills trees during colonization, and the red turpentine beetle, Dendroctonus valens LeConte, which often lives in their host without causing mortality. Bacteria from D. ponderosae were gram-positive Actinobacteria and Bacilli; one yeast also was tested. Bacteria from D. valens were Actinobacteria, Bacilli, and [gamma]-Proteobacteria. Bacteria from D. valens were more tolerant of monoterpenes than were those from D. ponderosae. Bacteria from D. ponderosae did not grow in the presence of [alpha]-pinene and 3-carene, and grew in, but were inhibited by, [beta]-pinene and [beta]-phellandrene. Limonene and myrcene had little inhibitory effect on bacteria from either beetle species. Tolerance to these antibiotic compounds appears to have resulted from adaptation to living in a terpene-rich environment.},
	keywords = {Dendroctonus},
	isbn = {0098-0331},
	author = {Adams, Aaron S. and Boone, Celia K. and Bohlmann, Jorg and Raffa, Kenneth F.}
}
@article {6017,
	title = {Electrophysiological and behavioral responses of Ips subelongatus to semiochemicals from its hosts, non-hosts, and conspecifics in China},
	journal = {Journal of Chemical Ecology},
	volume = {33},
	number = {2},
	year = {2007},
	month = {February},
	pages = {391-404},
	abstract = {Volatiles from hosts, non-hosts, interspecifics, and conspecifics of the Asian larch bark beetle, Ips subelongatus Motsch., were analyzed using both gas chromatographic-electroantennographic detection (GC-EAD) and gas chromatography/mass spectrometry (GC-MS) techniques, and field trapping bioassays in Inner Mongolia, China. GC-EAD experiments indicated that I. subelongatus antennae (both sexes) strongly responded not only to the major male-produced conspecific components, ipsenol, and ipsdienol, but also to other bark beetle compounds (cis-verbenol and verbenone), host monoterpenes (a-pinene, [beta]-pinene, and para-cymene) from Larix sp. logs, and non-host leaf (green leaf volatiles and geranyl acetone) and bark (C8-alcohols and trans-conophthorin) volatiles. Repeatable EAD responses were also found to two compounds from hindgut extracts that are undetectable by GC. One of these minor compounds was identified as amitinol. Field trapping experiments showed that the EAD-active, major male-hindgut component, racemic ipsenol, is the only individual compound that significantly attracted both sexes of I. subelongatus, whereas all other compounds, including previously reported pheromone components of European Ips cembrae, ipsdienol and 3-methyl-3-buten-1-ol, were unattractive. Ipsdienol, 3-methyl-3-buten-1-ol, or their binary blend had no synergistic or antagonistic effects on I. subelongatus attraction when combined with ipsenol, whereas cis-verbenol (a synomone) and verbenone (the antiaggregation semiochemical) inhibited its attraction to the ipsenol-containing attractive blend. A mixture of three EAD-active host monoterpenes, a-pinene, [beta]-pinene, and para-cymene, was unattractive, but interrupted the pheromone response of I. subelongatus. Geranyl acetone, one of the strong EAD-active non-host volatiles also significantly reduced the number of I. subelongatus captured in traps baited with ipsenol-containing attractive blend. Our results add support to the recent phylogenetic finding that European and Asian larch bark beetles should be regarded as two distinct species: I. cembrae infecting larch in Europe and I. subelongatus infesting larch in Asia},
	keywords = {Ips subelongatus},
	isbn = {0098-0331},
	author = {Zhang, Qing-He and Schlyter, Fredrik and Chen, Guofa and Wang, Yanjun}
}
@article {6020,
	title = {Aggregation pheromone of the Qinghai spruce bark beetle, Ips nitidus eggers},
	journal = {Journal of Chemical Ecology},
	volume = {35},
	number = {5},
	year = {2009},
	month = {May},
	pages = {610-617},
	abstract = {Volatiles from hindgut extracts of males of the Qinghai spruce bark beetle, Ips nitidus, from different attack phases (phase 1: unpaired males and phases 2-4: males joined with one to three females) and hindgut extracts of mated females were analyzed by gas chromatography-mass spectrometry (GC-MS)/flame ionization detection (FID) with both polar and enantioselective columns. The GC-MS/FID analyses demonstrated that unpaired males from attack phase 1 (nuptial chamber constructed) produced 2-methyl-3-buten-2-ol, approx. 74\%-(-)-ipsdienol, and (-)-cis-verbenol as major hindgut components, and (-)-trans-verbenol, (-)-ipsenol, (-)-verbenone, myrtenol, and 2-phenylethanol as minor or trace components. The quantities of 2-methyl-3-buten-2-ol and especially ipsdienol decreased after mating during phases 2-4, whereas the quantities of (-)-cis- and (-)-trans-verbenol did not change. In contrast, the quantity of (-)-ipsenol seemed to increase as mating activity progressed. After mating with three females (harem size = 3; phase 4), only trace to small amounts of male-specific compounds were detected from I. nitidus male hindguts. Chemical analysis of the hindgut extracts of mated females showed only trace amounts of semiochemicals. A field-trapping bioassay in Qinghai, China showed that the four-component "full blend" containing the three major components, 2-methyl-3-buten-2-ol, ([plus or minus])-ipsdienol, and (-)-cis-verbenol, plus a minor component, (-)-trans-verbenol, caught significantly more I. nitidus ([male]/[female]= 1:2.2) than did the unbaited control and two binary blends. The replacement of ([plus or minus])-ipsdienol with nearly enantiomerically pure (-)-ipsdienol in the "full blend" significantly reduced trap catches, which suggests that both enantiomers are needed for attraction. On the other hand, removal of (-)-trans-verbenol from the active "full blend" had no significant effect on trap catches. Our results suggest that the three major components, 2-methyl-3-buten-2-ol, 74\%-(-)-ipsdienol, and (-)-cis-verbenol (at 7:2:1), produced by unpaired fed males, are likely the aggregation pheromone components of I. nitidus, thus representing the first characterization of an aggregation pheromone system of a bark beetle native solely to China.},
	keywords = {Ips nitidus},
	isbn = {0098-0331},
	author = {Zhang, Qing-He and Ma, Jian-Hai and Zhao, Feng-Yu and Song, Li-Wen and Sun, Jiang-Hua}
}
@article {6015,
	title = {Electrophysiological and behavioral responses of Ips duplicatus aggregation pheromone in Inner Mongolia, China: amitinol as a potential pheromone component},
	journal = {Journal of Chemical Ecology},
	volume = {33},
	number = {7},
	year = {2007},
	month = {July},
	pages = {1303-1315},
	abstract = {Volatiles from Ips duplicatus male hindgut extracts and aeration samples of spruce logs colonized by the virgin males were analyzed by coupled gas chromatography-mass spectrometry (GC-MS), coupled gas chromatography-electroantennographic detection (GC-EAD), and field trapping bioassays in Inner Mongolia, China. GC-MS analyses showed that males from nuptial chambers (for reproduction) produced hindgut volatile profiles similar to those of maturation feeding males from the nonreproductive galleries. The known aggregation pheromone components, ipsdienol (Id) and E-myrcenol (EM) are the major constituents of this blend, followed by several minor bark beetle-related compounds: 2-methyl-3-buten-2-ol, ipsenol, cis-verbenol, verbenone, 2-phenylethanol, myrtenol, and trans-myrtanol. The enantiomeric composition of the Id from the male hindgut extracts was determined to be a racemic mixture (50/50) by enantioselective GC. GC-EAD experiments indicated that I. duplicatus antennae from both sexes responded strongly not only to the known aggregation pheromone components, Id and EM, but also to the other minor conspecific-produced compounds. The strongest antennal response was elicited by the major pheromone component, Id, which was ca. 2-3 times higher than that elicited by the second component, EM. Electroantennogram dose-responses indicated that antennal response threshold to Id was approximately 100 times lower than that of EM. No synergistic effects between these occurred at peripheral level. A strong and repeatable EAD response was found to a trace compound (flame ionization detection undetectable) from both hindgut and aeration samples. The compound was identified as amitinol (At) based on the retention time and a further EAD analysis of a synthetic mixture. In the field trapping experiments, At increased the attraction of I. duplicatus to the traps baited with a binary blend of EM/Id (1:1) in a synergistic manner when tested at a low release rate (1:1:0.1) but had no effect on catches at the high release rate (1:1:1). This result suggests that At might be a part of the Chinese I. duplicatus aggregation pheromone system. The production ratios of EM/Id from the Inner Mongolian population (EM/Id[approximately equal]1:2.0-4) were twice as high as those reported from Europe (EM/Id[approximately equal]1:9), corresponding well with the differences in the optimal response ratios},
	keywords = {Ips duplicatus},
	isbn = {0098-0331},
	author = {Zhang, Qing-He and Schlyter, Fredrik and Liu, Guang-Tian and Sheng, Mao-Ling and Birgersson, Goran}
}
@article {4880,
	title = {Aggregation Pheromones of Two Geographical Isolates of the New Guinea Sugarcane Weevil, Rhabdoscelus obscurus},
	journal = {Journal of Chemical Ecology},
	volume = {26},
	number = {12},
	year = {2000},
	pages = {2763-2780},
	abstract = {The aggregation pheromones were studied from two geographical isolates (Hakalau, Hawaii, and Silkwood, Queensland, Australia) of the New Guinea sugarcane weevil, Rhabdoscelus obscurus. Coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric (MS) analyses of Porapak Q volatile extract from male and from female Hawaiian R. obscurus revealed a single EAD-active, male-specific candidate pheromone, which was identified as 2-methyl-4-octanol (1). Corresponding volatile analyses from male and from female Australian R. obscurus consistently revealed three EAD-active, male-specific candidate pheromone components that were identified as 1, (E2)-6-methyl-2-hepten-4-ol (rhynchophorol) (2), and 2-methyl-4-heptanol (3). In field experiment 1 in Hakalau, Hawaii, traps baited with a stereoisomeric mixture of synthetic 1 (3 mg/day) plus sugarcane captured more weevils than did traps baited with 1 or sugarcane alone or no bait, indicating that 1 is the pheromone of the Hawaiian R. obscurus population. In field experiment 2, conducted in Silkwood, Australia, traps baited with stereoisomeric mixtures of synthetic 1, 2, and 3 (3 mg/day each) plus sugarcane caught more weevils than did unbaited traps or traps baited with 1, 2, and 3 or sugarcane. Testing candidate pheromone components 1, 2, and 3 in experiments 2-5 in all possible binary, ternary, and quaternary combinations with sugarcane, indicated that 1 and 2 in combination, but no singly, are pheromone components of the Australian R. obscurus population. Weevils from several locations in Australia and Hawaii could not be differentiated using traditional morphological characters or ultrastructural comparisons with scanning electron microscopy (SEM). However, comparisons of mtDNA sequences (cytochrome oxidase I; regions I1 to M4; 201 base pairs) revealed 5.5\% variation between the Hawaiian (N = 2) and the Australian (N = 4) samples. There was no intrapopulation variation in sequence data from the weevils from Hawaii versus Australia, suggesting that they are sibling species.<br />},
	keywords = {Rhabdoscelus obscurus},
	url = {http://www.springerlink.com/content/q7r8j3v10m001777/},
	author = {Giblin-Davis, R. M. and Gries, B. and Robertson, L. N. and Hara, A. H. and Gries, G. and Charles W. O{\textquoteright}Brien and Pierce, H. D.}
}
@article {1882,
	title = {Aggregation Pheromones of Two Geographical Isolates of the New Guinea Sugarcane Weevil, Rhabdoscelus obscurus },
	journal = {Journal of Chemical Ecology},
	volume = {26},
	year = {2000},
	pages = {2763-2780},
	chapter = {2763},
	abstract = {The aggregation pheromones were studied from two geographical isolates (Hakalau, Hawaii, and Silkwood, Queensland, Australia) of the New Guinea sugarcane weevil, Rhabdoscelus obscurus. Coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric (MS) analyses of Porapak Q volatile extract from male and from female Hawaiian R. obscurus revealed a single EAD-active, male-specific candidate pheromone, which was identified as 2-methyl-4-octanol (1). Corresponding volatile analyses from male and from female Australian R. obscurus consistently revealed three EAD-active, male-specific candidate pheromone components that were identified as 1, (E2)-6-methyl-2-hepten-4-ol (rhynchophorol) (2), and 2-methyl-4-heptanol (3). In field experiment 1 in Hakalau, Hawaii, traps baited with a stereoisomeric mixture of synthetic 1 (3 mg/day) plus sugarcane captured more weevils than did traps baited with 1 or sugarcane alone or no bait, indicating that 1 is the pheromone of the Hawaiian R. obscurus population. In field experiment 2, conducted in Silkwood, Australia, traps baited with stereoisomeric mixtures of synthetic 1, 2, and 3 (3 mg/day each) plus sugarcane caught more weevils than did unbaited traps or traps baited with 1, 2, and 3 or sugarcane. Testing candidate pheromone components 1, 2, and 3 in experiments 2-5 in all possible binary, ternary, and quaternary combinations with sugarcane, indicated that 1 and 2 in combination, but no singly, are pheromone components of the Australian R. obscurus population. Weevils from several locations in Australia and Hawaii could not be differentiated using traditional morphological characters or ultrastructural comparisons with scanning electron microscopy (SEM). However, comparisons of mtDNA sequences (cytochrome oxidase I; regions I1 to M4; 201 base pairs) revealed 5.5\% variation between the Hawaiian (N = 2) and the Australian (N = 4) samples. There was no intrapopulation variation in sequence data from the weevils from Hawaii versus Australia, suggesting that they are sibling species.<br />
},
	keywords = {Rhabdoscelus obscurus},
	issn = {0098-0331 },
	doi = {10.1023/A:1026437809875},
	url = {http://www.springerlink.com/content/q7r8j3v10m001777/},
	author = {Giblin-Davis, R. M. and Gries, B. and Robertson, L. N. and Hara, A. H. and Gries, G. and Charles W. O{\textquoteright}Brien and Pierce, H. D.}
}
