Colour and nectar help pitcher plants lure more insects
A field experiment shows that several signals together can attract different prey.
Pitcher plants do not use a single lure, but combine colour and nectar, among other things, to attract insects. This emerges from a peer-reviewed study of the North American species Sarracenia purpurea.
The researchers tested why plants sometimes use several signals that appear broadly to serve the same function. In animals, such a combination might consist of colour, scent and sound. In pitcher plants, examples include conspicuous veins in the leaf, nectar and volatile compounds.
For the study, the scientists made artificial models of the pitcher-shaped leaves. The models were given different combinations of red colour, nectar and volatile organic compounds. The researchers then placed them in the natural habitat of Sarracenia purpurea, a species found in nutrient-poor peatlands in North America.
The study first appeared in Functional Ecology on 27 December 2025. The researchers found support for two explanations. Different signals attracted different groups of insects, while some signals simultaneously increased the likelihood that relevant prey would notice the plant.
Colour and nectar together particularly increased the variety of prey caught. The bog specialist Myrmica lobifrons was also found more often on models with those signals. The researchers concluded that multiple signals may provide benefits for the plant that outweigh the energy and construction costs of producing them.
The volatile compounds produced a more nuanced picture. At artificially high concentrations, some insect groups responded to them, but at adjusted, biologically realistic concentrations there was no clear attraction to any one specific group. Nor did the combination of red colour and nectar attract more unique species than other treatments.
The research concerns the luring of prey, not the plant's complete food intake or reproductive success. The models were also artificial and cannot fully replicate the behaviour of real leaves. The study is therefore a controlled experiment on possible mechanisms, not evidence that all pitcher plants use the same strategy.
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 research status, method and main results were checked directly against the scientific article. The limitations of artificial models and the limited scope of the conclusion are explicitly included.
- confirmed The study appeared in Functional Ecology and is peer-reviewed. — The article is published in Functional Ecology and is available as a journal publication. source
- confirmed The researchers used artificial models with colour, nectar and volatile compounds. — This is stated in the article's methods description and summary. source
- confirmed Colour and nectar increased the variety of prey caught. — The authors report that both signals additively increased prey diversity. source
- confirmed At realistic concentrations, the volatile compounds were not clearly attractive to any one insect group. — This is explained in the article's supplementary results. source
Editor's note
This concerns peer-reviewed research using artificial plant models in the species' natural habitat. The results support two explanations for multiple signals, but do not constitute a general breakthrough for all carnivorous plants.Sources
- Multiple signalling increases both prey response and diversity in a carnivorous pitcher plant — Functional Ecology / Wiley
- It’s a trap — Nature Ecology & Evolution
More on this in Dutch media
- Het Parool — „bekerplant sarracenia purpurea”
- Trouw — „bekerplant sarracenia purpurea”
- NRC — „bekerplant sarracenia purpurea”