Papers by Marie Bengtsson
Research Square (Research Square), Apr 19, 2024
The great diversity of specialist plant-feeding insects suggests that host plant shifts may initi... more The great diversity of specialist plant-feeding insects suggests that host plant shifts may initiate speciation, even without geographic barriers. Pheromones and kairomones mediate sexual communication and host choice, and the response to these behaviourmodifying chemicals is under sexual and natural selection, respectively. The idea that the interaction of mate signals and habitat cues facilitates reproductive isolation and ecological speciation is well-established, while the traits and the underlying sensory mechanisms remain unknown. The larva of codling moth feeds in the apple. We show for the first time that the response of male moths to female sex pheromone relies upon Erdei et al.p. 2 (23) presence of a kairomone released from apple. In a non-host tree, attraction to pheromone alone is very strongly reduced, but is fully rescued by blending pheromone with the apple kairomone. This affords a mechanism how host plant shifts shape new mate-finding signals that can give rise to assortative mating and reproductive isolation.
Behaviour-modifying chemicals mediate sexual communication and host choice in insect herbivores. ... more Behaviour-modifying chemicals mediate sexual communication and host choice in insect herbivores. Sex pheromones are believed to attract insects by themselves, even though they are released into an atmosphere of plant odorants. We show for the first time that, in codling moth, feeding on apple and pear, that female pheromone is efficient for male attraction only in the presence of host plant odour. In non-host vegetation, male attraction to sex pheromone was very strongly reduced. The role of host odour in sex attraction was then substantiated by blending synthetic pheromone, codlemone, and the kairomone pear ester, a strong host plant attractant. An admixture of pear ester entirely rescued pheromone attraction in non-host vegetation. This field behavioural assay substantiates that host plant olfactory cues are integral part of sexual communication and mate recognition, which provides a mechanism for how shifts to new host plants produce new mate recognition signals.
Acta horticulturae, Oct 1, 2005
Journal of Insect Physiology, Feb 1, 2022
Specific mate communication and recognition underlies reproduction and hence speciation. Our stud... more Specific mate communication and recognition underlies reproduction and hence speciation. Our study provides new insights in Drosophila melanogaster premating olfactory communication. Mate communication evolves during adaptation to ecological niches and makes use of social signals and habitat cues. Female-produced, species-specific volatile pheromone (Z)-4-undecenal (Z4-11Al) and male pheromone (Z)-11-octadecenyl acetate (cVA) interact with food odour in a sex-specific manner. Furthermore, Z4-11Al, which mediates upwind flight attraction in both sexes, also elicits courtship in experienced males. Two isoforms of the olfactory receptor Or69a are co-expressed in the same olfactory sensory neurons. Z4-11Al is perceived via Or69aB, while the food odorant (R)-linalool is a main ligand for the other variant, Or69aA. However, only Z4-11Al mediates courtship in experienced males, not (R)-linalool. Behavioural discrimination is reflected by calcium imaging of the antennal lobe, showing distinct glomerular activation patterns by these two compounds. Male sex pheromone cVA is known to affect male and female courtship at close range, but does not elicit upwind flight attraction as a single compound, in to contrast to Z4-11Al. A blend of the food odour vinegar and cVA attracted females, while a blend of vinegar and female pheromone Z4-11Al attracted males, instead. Sex-specific upwind flight attraction to blends of food volatiles and male and female pheromone, respectively, adds a new element to Drosophila olfactory premating communication and is an unambiguous paradigm for identifying the behaviourally active components, towards a more complete concept of food-pheromone odour objects.
Entomologia Experimentalis Et Applicata, Sep 1, 1991
The sex pheromones of Spilonota ocellana D. & S. and Spilonota laricana Hein. (Lepidopter... more The sex pheromones of Spilonota ocellana D. & S. and Spilonota laricana Hein. (Lepidoptera:Tortricidae) were identified by chemical analysis and field trapping. Female moths of the two species produce (Z)‐8‐tetradecenyl acetate, (Z)‐8‐tetradecen‐1‐ol and dodecyl acetate in almost the same proportions (98:1:1 and 97:3:1). Males of both species were best attracted to a blend of 10:1 to 1:1 Z8‐14Ac:Z8‐14OH. This indicates that mating barriers other than sex pheromones exist between sympatric populations.
Functional Ecology, May 18, 2012
Summary1.In nature, the fruit fly Drosophila melanogaster is attracted to fermenting fruit. Micro... more Summary1.In nature, the fruit fly Drosophila melanogaster is attracted to fermenting fruit. Micro‐organisms like Saccharomyces yeasts growing on fruit occupy a commonly overlooked trophic level between fruit and insects. Although the dietary quality of yeast is well established for D. melanogaster, the individual contribution of fruit and yeast on host finding and reproductive success has not been established.2.Here, we show that baker's yeast Saccharomyces cerevisiae on its own is sufficient for fruit fly attraction, oviposition and larval development. In contrast, attraction and oviposition were significantly lower if non‐fermented grape juice or growth media were used, and yeast‐free grapes did not support larval development either.3.Despite a strong preference for fermented substrates, moderate attraction to and oviposition on unfermented fruit might be adaptive in view of the fly's capacity to vector yeast.4.Signals emitted by fruit were only of secondary importance because fermenting yeast without fruit induced the same fly behaviour as yeast fermenting on fruit. We identified a synthetic mimic of yeast odour, comprising ethanol, acetic acid, acetoin, 2‐phenyl ethanol and 3‐methyl‐1‐butanol, which was as attractive for the fly as fermenting grape juice or fermenting yeast minimal medium.5.Yeast odours represent the critical signal to establish the fly–fruit–yeast relationship. The traditional plant–herbivore niche concept needs to be updated, to accommodate for the role of micro‐organisms in insect–plant interactions.
Food Control, Apr 1, 2023
Agricultural and Forest Entomology, Aug 1, 2005
1 Two codling moth Cydia pomonella kairomonal attractants, ethyl (E,Z)‐2,4‐decadienoate (pear e... more 1 Two codling moth Cydia pomonella kairomonal attractants, ethyl (E,Z)‐2,4‐decadienoate (pear ester) and (E)‐β‐farnesene, were tested in an insecticide‐sprayed apple orchard and an orchard treated for mating disruption with synthetic pheromone (E,E)‐8,10‐dodecadienol (codlemone). Male captures with pear ester were higher in the pheromone‐treated than in the insecticide‐treated orchard, whereas captures with (E)‐β‐farnesene were not different. Subsequent wind tunnel experiments confirmed that pre‐exposure to sex pheromone codlemone increased the behavioural response of codling moth males to pear ester. This supports the idea that male attraction to the plant volatile pear ester and sex pheromone codlemone is mediated through the same sensory channels.2 Pear ester is a bisexual codling moth attractant and even captures of female moths were significantly increased in the pheromone‐treated orchard. In the laboratory wind tunnel, pheromone pre‐exposure had no effect on female response to pear ester, but significantly more mated than unmated codling moth females flew upwind towards a pear ester source. Differences in mating status in insecticide‐treated vs. pheromone‐treated orchards may thus account for the differences in female trap captures with pear ester.3 These findings are important with respect to monitoring of codling moth with pear ester in mating disruption orchards. They also emphasize the importance of host plant volatiles in pheromone‐mediated mating disruption, which has been neglected to date.
Environmental Entomology, Jun 1, 2000
Pheromone gland extracts of grape berry moth females, Endopiza viteana Clemens, contain the main ... more Pheromone gland extracts of grape berry moth females, Endopiza viteana Clemens, contain the main pheromone component, Z9 Ð12Ac, at Ϸ1.2 ng per female, together with both geometric isomers of 11Ð14Ac, and a number of saturated acetates and alcohols of the chain length 12Ð16. The analogous alcohol, Z9 Ð12OH, was found in some gland extracts. Trap capture of males was signiÞcantly increased by adding 0.5 or 2 g of Z11Ð14Ac to 10 g of the main compound, Z9 Ð12Ac; whereas, adding 0.5 or 2 g of E11Ð14Ac had no signiÞcant effect. In contrast, the addition of 5% Z9 Ð12OH to the main compound resulted in a strong reduction in trap capture. Traps baited with a blend of Z9 Ð12Ac and its geomeric isomer, E9 Ð12Ac, which was not detected in gland extracts, were signiÞcantly less attractive than traps baited with blends of Z9 Ð12Ac and Z11Ð14Ac. Knowledge of pheromone components and antagonists is essential for development of the mating disruption technique. The compounds identiÞed in E. viteana are behaviorally active in the three most important tortricid pests of grape, Vitis vinifera (L.), in Europe. It may thus be possible to use a single blend of synthetic pheromone for control of several species.
Sequences of OR69a variants used to produce transgenic “empty neuron” flies (Figure 2B). These ar... more Sequences of OR69a variants used to produce transgenic “empty neuron” flies (Figure 2B). These are 99-100% identical to sequences in the NCBI database. Text file
input file for statistical analysis (see also file "borrero R script - legend"
Food Control, 2021
Leafy vegetables undergo abiotic and biotic stresses, and a series of processing steps that cause... more Leafy vegetables undergo abiotic and biotic stresses, and a series of processing steps that cause mechanical injury. Breaching the epidermis alters phyllosphere structural and nutrient conditions, resulting in successional shifts in leaf microbiota and entry of human pathogens. This study examined damage during processing of baby leaves (Swiss chard, spinach) and concomitant microbial successional events. Machine-harvesting, washing, and packaging caused major phyllosphere perturbations, with increasing levels of leaf damage. Older leaves showed most damage, but plant species was influential. Diversity estimates of bacterial and fungal communities revealed shifts in microbiota post-harvest, particularly after the washing step. Relative abundance of Pseudomonadaceae and Enterobacteriaceae increased from field to bag. Bacterial species specific to different harvesting and processing steps replaced core microbiota species. While processing is unavoidable, procedures that mitigate leaf damage can enhance shelf-life and food safety.
Journal of Chemical Ecology, Apr 3, 2018
Z)-4-undecenal (Z4-11Al) is the volatile pheromone produced by females of the vinegar fly Drosoph... more Z)-4-undecenal (Z4-11Al) is the volatile pheromone produced by females of the vinegar fly Drosophila melanogaster. Female flies emit Z4-11Al for species-specific communication and mate-finding. A sensory panel finds that synthetic Z4-11Al has a characteristic flavour, which can be perceived even at the small amounts produced by a single female fly. Since only females produce Z4-11Al, and not males, we can reliably distinguish between single D. melanogaster males and females, according to their scent. Females release Z4-11Al at 2.4 ng/h and we readily sense 1 ng synthetic Z4-11Al in a glass of wine (0.03 nmol/L), while a tenfold concentration is perceived as a loud off-flavour. This corroborates the observation that a glass of wine is spoilt by a single D. melanogaster fly falling into it, which we here show is caused by Z4-11Al. The biological role of Z4-11Al or structurally related aldehydes in humans and the basis for this semiochemical convergence remains yet unclear.
Zeitschrift für Naturforschung C, Apr 1, 2001
The antennal responses o f codling moth females, Cydia pom onella, to volatiles from apple branch... more The antennal responses o f codling moth females, Cydia pom onella, to volatiles from apple branches with green fruits were recorded by electroantennography coupled to gas chroma tography. The antennae strongly responded to 4,8-dimethyl-l,3(£'),7-nonatriene, linalool, ß- )-a -fa rn esen e and methyl salicylate. These compounds were all present in volatile collections on Porapak Q from both living and cut branches. Analysis by the solid phase microextraction technique (SPM E) showed that the emission of some electrophysiologically active compounds increased after branches had been cut, especially 4,8-dim ethyl-l,3(£'),7-nonatriene, linalool and (E .E )a-farnesene. The identification o f apple volatiles eliciting antennal responses is the first step towards the identification of compounds mediating host-finding and oviposition in codling moth females.
bioRxiv (Cold Spring Harbor Laboratory), Apr 2, 2018
Specific mate recognition strongly relies on the chemical senses in many animals, and especially ... more Specific mate recognition strongly relies on the chemical senses in many animals, and especially in nocturnal insects. Two signal types lend to premating olfactory communication in terrestrial habitats: sex signals blend into an atmosphere of habitat odorants, where plant volatiles prevail. We show for the first time that males of the African cotton leafworm Spodoptera littoralis perceive female sex pheromone and volatiles of its plant host cotton as a unit, rather than as independent messages. In clean air, S. littoralis males are attracted to flawed pheromone signals, such as single synthetic pheromone components or even the pheromone of a sibling species, Oriental leafworm S. litura. Presence of host plant volatiles, however, strongly reduces the male response to deficient or heterospecific pheromone signals. That plant cues enhance discrimination of
Insect Biochemistry and Molecular Biology, Apr 1, 1994
Comparisons in the sex pheromone biosynthetic pathway were made between a normal (wild type) and ... more Comparisons in the sex pheromone biosynthetic pathway were made between a normal (wild type) and mutant strains of the cabbage looper moth, Trichoplusia hi, maintained in laboratory colonies. The sex pheromone of normal cabbage loopers consists of the major component, (Z-7-dodecenyl acetate) and five minor compounds (all acetate esters) that are biosynthesized from fatty acid precursors by a combination of All desaturation, chain shortening, reduction and acetylation. The mutant strain is characterized by higher amounts of Z-9-tetradecenyl acetate and lower amounts of Z-7-dodecenyl acetate. Amounts of fatty acid precursor found in pheromone glands were determined and indicated that some precursors were not chain shortened in the mutant strain. Amounts of all 12 carbon fatty acids were lower in the mutant strain compared to the normal strain. Incorporation studies using radiolabeled precursors indicated that the All desaturase, reductase and acetyl-CoA:fatty alcohol acetyltransferase were not affected by the mutation. However, it appeared that chain-shortening steps in the biosynthetic pathway were affected in the mutant strain. An in vitro chain-shortening assay was developed using several different deuterium-labeled fatty acyI-CoAs as suhstrates to determine how the chain shortening reactions were affected in the mutant strain. The amount of labeled product was determined by gas chromatography-mass spectrometry. The normal strain preferentially chain shortened Z-11-hexadecenoyl CoA by two rounds of #-oxidation to Z-7-dodecenoyl CoA. The mutant strain showed lower levels of chain shortening and only one round of #-oxidation occurred. Pheromone biosynthesis Chain shortening //-oxidation Trichoplusia ni
Insect Biochemistry and Molecular Biology, 1994
Comparisons in the sex pheromone biosynthetic pathway were made between a normal (wild type) and ... more Comparisons in the sex pheromone biosynthetic pathway were made between a normal (wild type) and mutant strains of the cabbage looper moth, Trichoplusia hi, maintained in laboratory colonies. The sex pheromone of normal cabbage loopers consists of the major component, (Z-7-dodecenyl acetate) and five minor compounds (all acetate esters) that are biosynthesized from fatty acid precursors by a combination of All desaturation, chain shortening, reduction and acetylation. The mutant strain is characterized by higher amounts of Z-9-tetradecenyl acetate and lower amounts of Z-7-dodecenyl acetate. Amounts of fatty acid precursor found in pheromone glands were determined and indicated that some precursors were not chain shortened in the mutant strain. Amounts of all 12 carbon fatty acids were lower in the mutant strain compared to the normal strain. Incorporation studies using radiolabeled precursors indicated that the All desaturase, reductase and acetyl-CoA:fatty alcohol acetyltransferase were not affected by the mutation. However, it appeared that chain-shortening steps in the biosynthetic pathway were affected in the mutant strain. An in vitro chain-shortening assay was developed using several different deuterium-labeled fatty acyI-CoAs as suhstrates to determine how the chain shortening reactions were affected in the mutant strain. The amount of labeled product was determined by gas chromatography-mass spectrometry. The normal strain preferentially chain shortened Z-11-hexadecenoyl CoA by two rounds of #-oxidation to Z-7-dodecenoyl CoA. The mutant strain showed lower levels of chain shortening and only one round of #-oxidation occurred. Pheromone biosynthesis Chain shortening //-oxidation Trichoplusia ni
Environmental Entomology, Oct 1, 1999
Attraction of codling moth males, Cydia pomonella (L.), to calling conspeciÞc females, female gla... more Attraction of codling moth males, Cydia pomonella (L.), to calling conspeciÞc females, female gland extracts, and synthetic pheromone was studied in a wind tunnel. A doseÐresponse test using a single source showed that female gland extracts attracted more males than codlemone, (E,E)-8,10-dodecadienol, alone. In choice tests, males preferred both calling females and gland extracts over synthetic codlemone. Calling females were as attractive as pheromone gland extracts, at a release rate of 100 pg codlemone/min. A 5-component blend of codlemone, its E,Z-isomer, (E)-9-dodecenol, dodecanol and tetradecanol was more attractive than codlemone in the wind tunnel. This study shows that other compounds, in addition to codlemone, are involved in sex attraction of codling moth males. Control of codling moth by mating disruption with synthetic pheromone is close to a breakthrough, although the method is not efÞcient at high population densities. The Þnding that codling moth uses a multicomponent pheromone offers the opportunity to enhance the behavioral activity of current dispenser formulations.
Ett feromon är en kemisk substans-eller oftast en blandning av substanser-som avges av en individ... more Ett feromon är en kemisk substans-eller oftast en blandning av substanser-som avges av en individ och som utlöser en beteendereaktion hos en annan individ av samma art. Det finns feromoner med olika funktioner, t.ex. aggregations-, alarm-, sexual-och äggläggningshämmande feromoner. Den substansblandning som en fjärilshona avger för att lockar till sig hanar inför parningen kallas för sexualferomon. sexualferomoner visar individernas r eproduktiva status och utgör en effektiv kommunikation mellan könen. "Semiochemicals", signal-eller budskapsdofter, är ett överordnat begrepp som även omfattar beteendeaktiva substanser mellan olika arter.
Uploads
Papers by Marie Bengtsson