Our ambition is to contribute with new insect control techniques to secure a sustainable food supply. Our main research focus is to identify insect sex pheromones and semiochemicals of plant and microbial origin and investigate how these behaviour-modifying chemicals can be used for insect control in horticultural crops.
In the wake of a changing climate, finding new control methods for pest insects on socioeconomically important crops are urgently needed. Particularly in Europe, where very few insecticides are registered for the protection of food crops, as well as in regions where food security is an increasingly pressing issue.
We currently focus our research on animal-microbe-interactions. The identification of chemical signals mediating cross-kingdom communication is fundamental for understanding the ecology of horticultural production systems. In addition, convergent perception of microbial odorants in insects and humans informs us about the contribution of yeasts and other microorganisms to the sensorial quality of horticultural crops and products.
Please read more about our ongoing research projects in the section below.
The fruit fly Drosophila melanogaster has long been subject of fundamental research in biology, leading to the discovery of chromosomes and DNA, and more recently the genetic code of olfactory receptors, which is an essential source of inspiration of our work.
Identification of semiochemicals involves two steps - chemical analysis of volatiles released by the producer, followed by bioassays demonstrating their behavioural role in the receiver. Electrophysiological techniques facilitate the selection of candidate compounds for behavioral assays. A powerful approach is to express single insect odorant receptors (ORs) in Drosophila sensory neurons: a single sensillum on the antenna, expressing a specific OR, is used to screen volatile collections from animals, plants or microbes for active compounds.
Most, if not all insects feeding on fruit are associated with yeasts. In Drosophila, yeast alone is sufficient to elicit attraction, oviposition and to support larval development. Fruit is a yeast growth substrate. The overwhelming role of yeasts in host plant finding has consequences also for the development of control techniques
The Drosophila female-produced pheromone demonstrates a partially overlapping odorant perception in insects and higher animals.
We distinguish single Drosophila females from males, according to this female pheromone, which is released at a few nanogram per hour. This observation has stimulated our interest in convergent perception of yeast odorants, since yeast aroma is attractive to insects and higher animals alike. We expect that a comparative analysis of the receptive range of insect and animal ORs leads to the discovery of yet unknown key odorants.
Researchers on this project
Guillermo Rehermann (Phd student)
Selected publications
Becher PG, Bengtsson M, Hansson BS, Witzgall P. 2010. Flying the fly: long-range flight behavior of Drosophila melanogaster to attractive odors. J chem Ecol 36:599-607 (doi: 10.1007/s10886-010-9794-2)
Becher PG, Flick G, Rozpedowska E, Schmidt A, Hagman A, Lebreton S, Larsson MC, Hansson BS, Piskur J, Witzgall P, Bengtsson M. 2012. Yeast, not fruit volatiles mediate attraction and development of the fruit fly Drosophila melanogaster. Funct Ecol 26:822-828 (doi:10.1111/j.1365-2435.2012.02006.x)
Becher PG, Hagman A, Verschut V, Chakraborty A, Rozpedowska E, Lebreton S, Bengtsson M, Flick G, Witzgall P, Piskur J. 2018. Chemical signaling and insect attraction is a conserved trait in yeasts. Ecol Evol 8:2962-2974 (doi: 10.1002/ece3.3905)
Becher PG, Lebreton S, Wallin EA, Hedenstrom E, Borrero-Echeverry F, Bengtsson M, Jorger V, Witzgall P. 2018. The scent of the fly. J chem Ecol 44:431-435 (doi: 10.1007/s10886-018-0950-4)
Lebreton S, Grabe V, Omondi AB, Ignell R, Becher PG, Hansson BS, Sachse S, Witzgall P. 2014. Love makes smell blind: mating suppresses pheromone attraction in Drosophila females via OR65a olfactory neurons. Sci Rep 4:7119 (doi:10.1038/srep07119)
Lebreton S, Trona S, Borrero-Echeverry F, Bilz F, Grabe V, Becher PG, Carlsson MA, Nässel DR, Hansson BS, Sachse S, Witzgall P. 2015. Feeding regulates sex pheromone attraction and courtship in Drosophila females. Sci Rep 5:13132 (doi:10.1038/srep13132)
Lebreton S, Borrero-Echeverry F, Gonzalez F, Solum M, Wallin E, Hedenström E, Hansson BS, Gustavsson A-L, Bengtsson M, Birgersson G, Walker WB, Dweck H, Becher PG, Witzgall P. 2017. A Drosophila female pheromone elicits species-specific long-range attraction via an olfactory channel with dual specificity for sex and food. BMC Biology 15:88 (doi:10.1186/s12915-017-0427-x)
Drosophila suzukii has invaded the Americas and Europe during the past decade. It feeds on unripe fruit, in contrast to its close relative the common fruit fly D. melanogaster, and has thus become the single most important pest of fruit and berries.
In Sweden, wild berries are of cultural and economic importance, and they are a vital resource for the avian and mammalian fauna - these berries are not infested by native insects. A citizen-science project monitors the dispersal of D. suzukii and participates in the development of a yeast-based attractant.
Researchers on this project
Isabella Kleman
Guillermo Rehermann (Phd student)
Karolina Sahle
Selected publications
Mori BA, Whitener AB, Leinweber Y, Revadi S, Beers EH, Witzgall P, Becher PG. 2017. Enhanced yeast feeding following mating facilitates control of the invasive fruit pest Drosophila suzukii. J appl Ecol 54:170–177 (doi:10.1111/1365-2664.12688)
Tephritid fruit flies are of great economic importance in many vegetable and fruit crops worldwide. We apply our basic knowledge of fly chemical ecology to identify fly semiochemicals for development of monitoring and population control.
Researchers on this project
William B. Walker (Researcher)
Selected publications
Biasazin TD, Larsson Herrera S, Kimbokota F, Dekker T. 2019. Translating olfactomes into attractants: shared volatiles provide attractive bridges for polyphagy in fruit flies. Ecology Letters 22:108-118. (doi:10.1111/ele.13172)
Candia IF, Bautista V, Larsson Herrera S, Walter A, Ortuño Castro N, Tasin M, Dekker T. 2019. Potential of locally sustainable food baits and traps against the Mediterranean fruit fly Ceratitis capitata in Bolivia. Pest Manag Sc 75:1671-1680. (doi:10.1002/ps.5286)
We have investigated the chemical ecology and behavioural physiology of codling moth, Cydia pomonella. The larvae are feeding on apple pear and walnut. This knowledge has been brought to practical application, for population monitoring and control. We have, through an off-spin company, registered pheromone-mediated mating disruption
Researchers on project
William B. Walker (Researcher)
Selected publications
Bengtsson JM, Trona F, Montagne N, Anfora G, Ignell R, Witzgall P, Jacquin-Joly E. 2012. Putative chemosensory receptors of the codling moth, Cydia pomonella, identified by antennal transcriptome analysis. PLoS One 7(2):e31620 (doi: 10.1371/journal.pone.0031620)
Bengtsson JM, Gonzalez F, Cattaneo AM, Montagné N, Walker WB, Bengtsson M, Anfora G, Ignell R, Jacquin-Joly E, Witzgall P. 2014. A predicted sex pheromone receptor of codling moth Cydia pomonella detects the plant volatile pear ester. Front Ecol Evol 2:33 (doi:10.3389/fevo.2014.00033)
Knight AL, Witzgall P. 2013. Combining mutualistic yeast and pathogenic virus - a novel method for codling moth control. J chem Ecol 39:1019-1026 (doi:10.1007/s10886-013-0322-z)
Trona F, Anfora G, Bengtsson M, Witzgall P, Ignell R. 2010. Coding and interaction of sex pheromone and plant volatile signals in the antennal lobe of the codling moth Cydia pomonella. J exp Biol 213:4291-4303 (doi:10.1242/ jeb.047365)
Trona F, Anfora G, Balkenius A, Bengtsson M, Tasin M, Knight A, Janz N, Witzgall P, Ignell R. 2013. Neural coding merges sex and habitat chemosensory signals in an insect herbivore. Proc R Soc B 280:20130267 (doi:10.1098/rspb.2013.0267)
Walker WB, Gonzalez F, Garczynski SF, Witzgall P. 2016. The chemosensory receptors of codling moth Cydia pomonella - expression in larvae and adults. Sci Rep 6:23518 (doi:10.1038/srep23518)
Witzgall P, Stelinski L, Gut L, Thomson D. 2008. Codling moth management and chemical ecology.
Pilot studies show that a rich microbiome, composed of endophytic bacteria and yeasts, essentially contributes to the flavour of fruit and berries. These microorganisms might even confer a healthful effect. A surprising finding is that isolated yeasts and bacteria, by themselves, produce rich and fruit-like bouquets.
We investigate the microbiomes of apple, blueberry and raspberry for the occurrence of odour-active microorganisms, using flavourists, a taste panel and chemical analysis. Our hypothesis is that select microorganisms have the potential to contribute to food processing, facilitate preparation of natural flavours with minimal environmental footprint, and even enable crop improvement via pollinating insects.
Innovative natural food flavouring, especially when derived from the raw materials used for processing, is valuable for food industries and the horticultural sector alike. Comparing fruit microbiomes over growing regions will show a possibly contribution to the terroir, regionally characteristic differences in fruit flavour.
Researchers on project
Guillermo Rehermann (Phd student)
Collaboration
Einar Willumsen, Brøndby, Denmark
Selected publications
Ljunggren J, Borrero-Echeverry F, Chakraborty A, Lindblom TU, Hedenström E, Karlsson M, Witzgall P, Bengtsson M. 2019. Yeast volatomes differentially effect larval feeding in an insect herbivore. Appl Environm Microbiol 85: e01761-19 (doi:10.1128/AEM.01761-19)
Unit Leader: Peter Witzgall (Prof)
Guillermo Rehermann (Phd student)
William B. Walker (Researcher)
Alumni
Stefanos Andreadis
Anna-Carin Bäckman
Felipe Borrero
Miryan Coracini
Francisco Gonzalez
Sebastien Lebreton
Boyd Mori