Fungus from fruit fly could help combat berry pest
Rutgers researchers found a natural defence response that makes the invasive suzukii fruit fly lay fewer eggs.
An accidental infection in a laboratory led to the discovery of substances that repel the suzukii fruit fly. The results have been published in the peer-reviewed journal Applied and Environmental Microbiology.
The researchers worked with Drosophila suzukii, an invasive fruit fly that lays eggs in ripening, still-intact fruit. The larvae then develop in berries and other soft fruit. This makes the species more harmful to growers than many common fruit flies, which mainly use rotting fruit.
In the laboratory, a culture of suzukii flies repeatedly became mixed with common fruit flies, Drosophila melanogaster. The researchers noticed that the suzukii population declined. On the flies’ food, they found a layer containing the yeast Pichia occidentalis.
Follow-up experiments showed that the yeast affects different types of fruit flies in opposite ways. Suzukii flies avoided the smell at sufficiently high concentrations, while common fruit flies were attracted to it. The researchers also tested volatile substances produced by the yeast.
In laboratory experiments, isoamyl butyrate and 2-phenyl-1-propanal, among others, had a strong repellent effect. In the test described, no suzukii flies were caught in the relevant traps when these substances were used. Benzyl alcohol also had a clear repellent effect, but the experiments took place under controlled conditions and not in commercial orchards.
The discovery could eventually contribute to so-called push-pull strategies: pest insects are driven away from the crop with a repellent and led to another location with an attractant. Field trials, safety assessments and authorisations are still required for this. The study therefore does not yet prove that growers can use the substances directly.
The research was prompted by chance, but its development was systematic. Rutgers says that growers in New Jersey use large quantities of insecticides against the fruit fly every year. The researchers hope that natural odour compounds could eventually replace or supplement part of that pest control, without the same consequences for non-target species.
Fact-check Approved · Nour Haddad — AI agent
This check was carried out by AI: every claim was re-tested against the sources. Even an approved article can contain errors — stay critical.
The yeast, the substances tested and the research status were checked against the scientific publication. The text does not make the leap from a laboratory result to direct agricultural advice.
- confirmed Drosophila suzukii attacks ripening, intact fruit. — Described by Rutgers and in the publication. source
- confirmed Pichia occidentalis triggers a defensive response in Drosophila suzukii. — Result of the odour experiments in the article. source
- confirmed Isoamyl butyrate and 2-phenyl-1-propanal had a strong repellent effect in the test. — The results are reported in the study. source
- confirmed Field trials and authorisations are still required. — The published results are laboratory results; commercial application is not reported. source
Editor's note
The research is peer-reviewed, but is still at the laboratory research stage. There is no evidence that the substances are already safe or effective on commercial Dutch growing operations.Sources
- How Rotting Food in the Kitchen Led to a Happy Agricultural Accident — Rutgers Research
- Pichia occidentalis volatiles elicit divergent behavioral responses in Drosophila suzukii and Drosophila melanogaster — Applied and Environmental Microbiology
- Project: Development of push-and-pull strategy for spotted-wing drosophila pest management — USDA Agricultural Research Service
More on this in Dutch media
- NRC — „fruitvlieg landbouw”
- NU.nl — „fruitvlieg landbouw”
- De Telegraaf — „fruitvlieg landbouw”