| 1. |
- Andersson, Martin, et al.
(författare)
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Identification of Sex Pheromone Components of the Hessian Fly, Mayetiola destructor
- 2009
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Ingår i: Journal of Chemical Ecology. - : Springer Science and Business Media LLC. - 0098-0331 .- 1573-1561. ; 35, s. 81-95
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Tidskriftsartikel (refereegranskat)abstract
- Coupled gas chromatographic (GC)-electroantennographic detection (EAD) analyses of ovipositor extract of calling Hessian fly, Mayetiola destructor, females revealed that seven compounds elicited responses from male antennae. Four of the compounds-(2S)-tridec-2-yl acetate, (2S,10Z)-10-tridecen-2-yl acetate, (2S,10E)-10-tridecen-2-yl acetate, and (2S,10E)-10-tridecen-2-ol-were identified previously in female extracts. Two new EAD-active compounds, (2S,8Z,10E)-8,10-tridecadien-2-yl acetate and (2S,8E,10E)-8,10-tridecadien-2-yl acetate, were identified by GC-mass spectroscopy (MS) and the use of synthetic reference samples. In a Y-tube bioassay, a five-component blend (1 ng (2S)-tridec-2-yl acetate, 10 ng (2S,10E)-10-tridecen-2-yl acetate, 1 ng (2S,10E)-10-tridecen-2-ol, 1 ng (2S,8Z,10E)-8,10-tridecadien-2-yl acetate, and 1 ng (2S,8E,10E)-8,10-tridecadien-2-yl acetate) was as attractive to male Hessian flies as a similar amount of female extract (with respect to the main compound, (2S,10E)-10-tridecen-2-yl acetate). The five-component blend was more attractive to male flies than a three-component blend lacking the two dienes. Furthermore, the five-component blend was more attractive than a blend with the same compounds but that contained one tenth the concentration of (2S,8E,10E)-8,10-tridecadien-2-yl acetate (more accurately mimicking the ratios found in female extract). This suggests that the ratios emitted by females might deviate from those in gland extracts. In a field-trapping experiment, the five-component blend applied to polyethylene cap dispensers in a 100:10 mu g ratio between the main component and each of the other blend components attracted a significant number of male Hessian flies. Also, a small-plot field test demonstrated the attractiveness of the five-component blend to male Hessian flies and suggests that this pheromone blend may be useful for monitoring and predicting Hessian fly outbreaks in agricultural systems.
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| 2. |
- Andersson, Martin N, et al.
(författare)
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A sex pheromone receptor in the Hessian fly Mayetiola destructor (Diptera, Cecidomyiidae)
- 2016
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Ingår i: Frontiers in Cellular Neuroscience. - : Frontiers Media SA. - 1662-5102. ; 10:SEP2016
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Tidskriftsartikel (refereegranskat)abstract
- The Hessian fly, Mayetiola destructor Say (Diptera, Cecidomyiidae), is a pest of wheat and belongs to a group of gall-inducing herbivores. This species has a unique life history and several ecological features that differentiate it from other Diptera such as Drosophila melanogaster and blood-feeding mosquitoes. These features include a short, non-feeding adult life stage (1–2 days) and the use of a long-range sex pheromone produced and released by adult females. Sex pheromones are detected by members of the odorant receptor (OR) family within the Lepidoptera, but no receptors for similar long-range sex pheromones have been characterized from the Diptera. Previously, 122 OR genes have been annotated from the Hessian fly genome, with many of them showing sex-biased expression in the antennae. Here we have expressed, in HEK293 cells, five MdesORs that display male-biased expression in antennae, and we have identified MdesOR115 as a Hessian fly sex pheromone receptor. MdesOR115 responds primarily to the sex pheromone component (2S,8E,10E)-8,10-tridecadien-2-yl acetate, and secondarily to the corresponding Z,E-isomer. Certain sensory neuron membrane proteins (i.e., SNMP1) are important for responses of pheromone receptors in flies and moths. The Hessian fly genome is unusual in that it encodes six SNMP1 paralogs, of which five are expressed in antennae. We co-expressed each of the five antennal SNMP1 paralogs together with each of the five candidate sex pheromone receptors from the Hessian fly and found that they do not influence the response of MdesOR115, nor do they confer responsiveness in any of the non-responsive ORs to any of the sex pheromone components identified to date in the Hessian fly. Using Western blots, we detected protein expression of MdesOrco, all MdesSNMPs, and all MdesORs except for MdesOR113, potentially explaining the lack of response from this OR. In conclusion, we report the first functional characterization of an OR from the Cecidomyiidae, extending the role of ORs as long-range sex pheromone detectors from the Lepidoptera into the Diptera.
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| 3. |
- Andersson, Martin N, et al.
(författare)
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Antennal transcriptome analysis of the chemosensory gene families in the tree killing bark beetles, Ips typographus and Dendroctonus ponderosae (Coleoptera: Curculionidae: Scolytinae)
- 2013
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Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: The European spruce bark beetle, Ips typographus, and the North American mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Curculionidae: Scolytinae), are severe pests of coniferous forests. Both bark beetle species utilize aggregation pheromones to coordinate mass-attacks on host trees, while odorants from host and non-host trees modulate the pheromone response. Thus, the bark beetle olfactory sense is of utmost importance for fitness. However, information on the genes underlying olfactory detection has been lacking in bark beetles and is limited in Coleoptera. We assembled antennal transcriptomes from next-generation sequencing of I. typographus and D. ponderosae to identify members of the major chemosensory multi-gene families. Results: Gene ontology (GO) annotation indicated that the relative abundance of transcripts associated with specific GO terms was highly similar in the two species. Transcripts with terms related to olfactory function were found in both species. Focusing on the chemosensory gene families, we identified 15 putative odorant binding proteins (OBP), 6 chemosensory proteins (CSP), 3 sensory neuron membrane proteins (SNMP), 43 odorant receptors (OR), 6 gustatory receptors (GR), and 7 ionotropic receptors (IR) in I. typographus; and 31 putative OBPs, 11 CSPs, 3 SNMPs, 49 ORs, 2 GRs, and 15 IRs in D. ponderosae. Predicted protein sequences were compared with counterparts in the flour beetle, Tribolium castaneum, the cerambycid beetle, Megacyllene caryae, and the fruit fly, Drosophila melanogaster. The most notable result was found among the ORs, for which large bark beetle-specific expansions were found. However, some clades contained receptors from all four beetle species, indicating a degree of conservation among some coleopteran OR lineages. Putative GRs for carbon dioxide and orthologues for the conserved antennal IRs were included in the identified receptor sets. Conclusions: The protein families important for chemoreception have now been identified in three coleopteran species (four species for the ORs). Thus, this study allows for improved evolutionary analyses of coleopteran olfaction. Identification of these proteins in two of the most destructive forest pests, sharing many semiochemicals, is especially important as they might represent novel targets for population control.
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| 4. |
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| 5. |
- Bengtsson, Jonas, et al.
(författare)
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Conserved, Highly Specialized Olfactory Receptor Neurons for Food Compounds in 2 Congeneric Scarab Beetles, Pachnoda interrupta and Pachnoda marginata
- 2011
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Ingår i: Chemical Senses. - : Oxford University Press (OUP). - 0379-864X .- 1464-3553. ; 36, s. 499-513
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Tidskriftsartikel (refereegranskat)abstract
- Few studies have systematically addressed evolutionary changes in olfactory neuron assemblies, either by genetic drift or as an adaptation to specific odor environments. We have studied the sense of olfaction in 2 congeneric scarab beetles, Pachnoda interrupta Olivier and Pachnoda marginata Drury (Coleoptera: Scarabaeidae: Cetoniinae), which are both opportunistic polyphages, feeding mainly on fruit and flowers. The 2 species occur in dissimilar habitats: P. interrupta is found in dry savannah, and P. marginata in tropical parts of equatorial Africa. To study how these species may have adapted their sense of olfaction to their odor environments, we utilized single-unit electrophysiology on olfactory sensilla with a wide selection of food-related compounds. Despite the differences in habitat, we found that the species shared most of the physiological types of olfactory receptor neurons (ORNs) encountered, although their proportions frequently varied between the species. The high degree of conservation in olfaction between the species implies that a similar sensory strategy is efficient for food search in both habitats. However, shifts in proportions of receptor neuron classes, and slight shifts in response profiles and/or presence of some ORN classes unique to either species, may reflect adaptation to a different set of hosts.
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| 6. |
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| 7. |
- Bengtsson, Jonas, et al.
(författare)
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Field Attractants for Pachnoda interrupta Selected by Means of GC-EAD and Single Sensillum Screening
- 2009
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Ingår i: Journal of Chemical Ecology. - : Springer Science and Business Media LLC. - 0098-0331 .- 1573-1561. ; 35, s. 1063-1076
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Tidskriftsartikel (refereegranskat)abstract
- The sorghum chafer, Pachnoda interrupta Olivier (Coleoptera: Scarabaeidae: Cetoniinae), is a key pest on sorghum, Sorghum bicolor (L.) Moench (Poaceae), in Ethiopia. At present there is a lack of efficient control methods. Trapping shows promise for reduction of the pest population, but would benefit from the development of attractive lures. To find attractants that could be used for control of P. interrupta, either by mass trapping or by monitoring as part of integrated pest management, we screened headspace collections of sorghum and the highly attractive weed Abutilon figarianum Webb (Malvaceae) for antennal activity using gas chromatograph-coupled electroantennographic detection (GC-EAD). Compounds active in GC-EAD were identified by combined gas chromatography and mass spectrometry (GC-MS). Field trapping suggested that attraction is governed by a few influential compounds, rather than specific odor blends. Synthetic sorghum and abutilon odor blends were attractive, but neither blend outperformed the previously tested attractants eugenol and methyl salicylate, of which the latter also was part of the abutilon blend. The strong influence of single compounds led us to search for novel attractive compounds, and to investigate the role of individual olfactory receptor neurons (ORNs) in the perception of kairomones. We screened the response characteristics of ORNs to 82 putative kairomones in single sensillum recordings (SSR), and found a number of key ligand candidates for specific classes of ORNs. Out of these key ligand candidates, six previously untested compounds were selected for field trapping trials: anethole, benzaldehyde, racemic 2,3-butanediol, isoamyl alcohol, methyl benzoate and methyl octanoate. The compounds were selected on the basis that they activated different classes of ORNs, thus allowing us to test potential kairomones that activate large non-overlapping populations of the peripheral olfactory system, while avoiding redundant multiple activations of the same ORN type. Field trapping results revealed that racemic 2,3-butanediol is a powerful novel attractant for P. interrupta.
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| 8. |
- Bengtsson, Jonas, et al.
(författare)
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Pheromone-based Mating and Aggregation in the Sorghum Chafer, Pachnoda interrupta
- 2010
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Ingår i: Journal of Chemical Ecology. - : Springer Science and Business Media LLC. - 0098-0331 .- 1573-1561. ; 36, s. 768-777
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Tidskriftsartikel (refereegranskat)abstract
- Adults of the sorghum chafer, Pachnoda interrupta Olivier (Coleoptera: Scarabaeidae: Cetoniinae), form aggregations during the mating period in July, but also in October. The beetles aggregate on food sources, e.g., Acacia spp. trees or sorghum with ripe seeds, to feed and mate. During the mating season, field trapping experiments with live beetles as bait demonstrated attraction of males to unmated females, but not to mated females or males, indicating the presence of a female-emitted sex pheromone. Unmated females combined with banana (food source) attracted significantly more males and females than did unmated females alone. Other combinations of beetles with banana were not more attractive than banana alone. Thus, aggregation behavior appears to be guided by a combination of pheromone and host volatiles. Females and males were extracted with hexane during the mating period, and the extracts were compared by using GC-MS. In a field trapping experiment, 19 compounds found only in females were tested, both singly and in a mixture. Traps baited with one of the female-associated compounds, phenylacetaldehyde, caught significantly more beetles than any other treatment. However, the sex ratio of beetles caught in these traps did not differ from that of control traps, and it is possible that other components may be involved in the sex pheromone signal. Furthermore, traps baited with a mixture of all 19 compounds attracted significantly fewer beetles than did phenylacetaldehyde alone.
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| 9. |
- Boddum, Tina, et al.
(författare)
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Gall midge olfaction: Pheromone sensitive olfactory neurons in Contarinia nasturtii and Mayetiola destructor
- 2010
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Ingår i: Journal of Insect Physiology. - : Elsevier BV. - 0022-1910 .- 1879-1611. ; 56, s. 1306-1314
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Tidskriftsartikel (refereegranskat)abstract
- This study describes the morphology and function of the antennal sensilla in two gall midge species, Contarinia nasturtii and Mayetiola destructor, where multi-component sex pheromones have been identified. Both species possess sensilla trichodea, s. coeloconica, s. chaetica and s. circumfila. Sensilla circumfila, which consist of several sensilla that bifurcate and fuse into one structure, are unique for the gall midges. In C. nasturtii s. circumfila are sexually dimorphic. In males, they form elongated loops suspended on cuticular spines, whereas in females they run like worm-like structures directly on the antennal surface. Single sensillum recordings demonstrated that olfactory sensory neurons housed in male s. circumfila in C. nasturtii responded to the female sex pheromone. In M. destructor, S. circumfila were attached to the antennal surface in both sexes, and displayed no response to sex pheromone components.A sexual dimorphism was also found in the number of s. trichodea per antennal segment in both C. nasturtii (male 1 vs. female 7) and M. destructor (male 13 vs. female 10). OSNs located in male M. destructor s. trichodea responded to the sex pheromone. This is the first gall midge single sensillum study, and the first demonstration of the functional significance of s. circumfila. (C) 2010 Elsevier Ltd. All rights reserved.
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| 10. |
- Boddum, Tina, et al.
(författare)
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Host Attraction and Selection in the Swede Midge (Contarinia nasturtii)
- 2018
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Ingår i: Frontiers in Ecology and Evolution. - : Frontiers Media SA. - 2296-701X. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Gall midges (Diptera: Cecidomyiidae) are a speciose family that, as adults, are short lived (lasting only a few days), they use olfactory cues for host and mate localization, and their host plant specificity is a key characteristic of the family. These traits make them good models with which to study the role of olfaction in speciation. The overall objective of this study was to analyze the host selection behavior of the gall midge, Contarinia nasturtii, a crucifer specialist that also is a crucifer pest. Here, we demonstrate that the host specificity of gravid C. nasturtii females was initiated by the olfactory-driven host plant choice during oviposition. Olfactory preference of the female, while narrow, encompassed more plants than were accepted for egg-laying, indicating that other factors following the initial olfactory attraction are involved in ultimate host choice. Similarly, C. nasturtii showed flexibility in host plant choice depending on which plants were available for oviposition. Larvae developed on host plants selected by females for oviposition. This slightly broader range of olfactory preference over acceptance, and the flexibility in host choice, might be the basis for the rapid speciation reported in the gall midge family. Furthermore, we assessed whether ubiquitous and/or family-specific plant odors are involved in the attraction of gravid C. nasturtii to their hosts. For that, we used the crucifer Arabidopsis thaliana, which has a broad range of defined ecotypes and large number of mutants. The attraction of C. nasturtii to two A. thaliana-types were tested; one that does not produce the ubiquitous green leaf volatiles (Columbia, Col-0), and a knock-out mutant which does not produce the crucifer-specific glucosinolates. Surprisingly, C. nasturtii was attracted to both types, indicating that neither of these compounds, nor their breakdown products (e.g., isothiocyanates), are essential for C. nasturtii host attraction.
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