idw – Informationsdienst Wissenschaft
Nachrichten, Termine, Experten
Nachrichten, Termine, Experten
Parasitic wasps respond to extremely small scent quantities
Parasitic wasps of the genus Trichogramma are among the smallest insects in the world—yet they play an important role in natural ecosystems and agricultural landscapes as natural antagonists of pest species. Research teams from the Universities of Regensburg, Wageningen and Groningen have now identified for the first time the sex pheromone of a Trichogramma wasp. The study shows that unimaginably small amounts of the female pheromone are sufficient to attract males and trigger their courtship behaviour.
The females of Trichogramma turkestanica, measuring only about 0.4 millimetres in length, parasitize the eggs of various moths species. Their larvae develop inside the eggs, ultimately killing the host. Because of this lifestyle, the wasps are mass-reared worldwide and used as beneficial insects for the biological control of insect pests.
It has long been known that Trichgramma wasps rely on sex pheromones to locate mates. However, chemically identifying these signals has proven extremely challenging, as the insects produce only minute quantities of these pheromones. Nevertheless, the team in Wageningen from the Laboratories of Organic Chemistry and Entomology succeeded in isolating two compounds produced exclusively by females. “Only a few nanograms of each compound were available for structural elucidation, and their complex stereochemistry posed an additional challenge”, explains Teris van Beek, principal investigator of the Wageningen research team.
After many years of research, the two molecules were finally synthesized by the team of Adriaan Minnaard in Groningen. Whether they were indeed biologically active, initially remained unclear—until the recent behavioural experiments conducted by the researchers from Regensburg. “Seeing for the first time under the microscope how males of the size of a sandgrain move targetedly toward the pheromone and perform a kind of courtship dance was a real goosebumps moment,” says Joachim Ruther, head of the Regensburg research team.
What is particularly remarkable is the extraordinary potency of the attractant: as little as about 600 attograms (6 × 10⁻¹⁶ grams) were sufficient to trigger the males’ behavioural response—an almost inconceivably small amount.
For comparison: If a single sugar cube were dissolved in all the water of Lake Geneva, the amount of sugar contained in about a tablespoon of that water would roughly correspond to the pheromone dose to which the Trichogramma males still respond.
In the long term, the sex pheromone could be used in biological pest control to monitor the presence of these beneficial insects in agricultural landscapes. First, however, it must be demonstrated that the pheromone reliably attracts males under natural field conditions.
Prof. Dr. Joachim Ruther
Institut für Zoologie, Universität Regensburg
Phone.: +49 176 43973351
Mail: Joachim.Ruther@ur.de
van Beek, T, Kaniraj, J.P., Dornbusch, A., Smid, H.M., Houtman, M., Czak, K., Beijleveld, H., Silva, I.M.M.S., Posthumus, M.A.1, van Loon, J.J.A. Fatouros, N.E., Francke, W. Minnaard, A.J. & Ruther, J. (2026) Absolute configuration, improved synthesis and femtogram-level behavioral activity of the sex pheromone of the minute parasitoid wasp Trichogramma turkestanica. Scientific Reports
https://doi.org/10.1038/s41598-026-46414-z
Stubby-winged male of the parasitic wasp Trichogramma turkestanica. The inset shows a size compariso ...
Source: Joachim Ruther
Copyright: Joachim Ruther
Criteria of this press release:
Journalists, Scientists and scholars, Students
Biology
transregional, national
Research results, Scientific Publications
English
Stubby-winged male of the parasitic wasp Trichogramma turkestanica. The inset shows a size compariso ...
Source: Joachim Ruther
Copyright: Joachim Ruther
You can combine search terms with and, or and/or not, e.g. Philo not logy.
You can use brackets to separate combinations from each other, e.g. (Philo not logy) or (Psycho and logy).
Coherent groups of words will be located as complete phrases if you put them into quotation marks, e.g. “Federal Republic of Germany”.
You can also use the advanced search without entering search terms. It will then follow the criteria you have selected (e.g. country or subject area).
If you have not selected any criteria in a given category, the entire category will be searched (e.g. all subject areas or all countries).
