What insects does the carnivorous plant Sarracenia catch?

🌿 Biology & Behavior

What does a Sarracenia actually catch?
Prey in nature and in our gardens

From ants and blowflies to moths and wasps: the trumpet pitcher plant's trapping strategy under the microscope

Killian Dupont, Grower at carnivorousplantshop

Sarracenia is a genus of carnivorous plants native to the United States and Canada. Most species grow on the East Coast, in open bogs often surrounded by pine forests. In these nutrient-poor, wet soils, they can absorb extra nutrients such as nitrogen (N) and phosphorus (P) through their pitchers by catching and digesting small insects and other prey. But what exactly do these pitchers catch? And does it differ between nature and a garden in Belgium or the Netherlands?

Sarracenia leucophylla in haar natuurlijke habitat

Fig. 1. Sarracenia in its natural habitat: open peat bogs surrounded by pine forests on the East Coast of the US. The pitchers rise above the vegetation and function as passive traps. Photo: Sarracenia leucophylla

Prey in nature

The composition of the catch differs remarkably between species. Not every Sarracenia targets the same prey.

Species Main prey Special feature
S. rubra Ants, non-flying insects Low, narrow pitchers; efficient for ground insects
S. minor Ants, non-flying insects Has translucent spots ("false exits") that disorient insects
S. psittacina Ants, aquatic organisms Fish-trap shape: can actively catch organisms in water
S. flava Flies, beetles, wasps, ants Large pitchers; produces coniine (anesthetic) in the pitcher
S. leucophylla Flies, moths, butterflies, ants White hood specifically attracts moths
S. alata Flies, beetles, ants Similar to S. flava in trapping strategy
S. purpurea Ants, beetles, various insects Low, open pitcher; no hood, acts more as a rainwater basin
Moths and the white hood: The fact that S. leucophylla catches a remarkably large number of moths and butterflies seems to be related to the white color of its hood. White reflects UV light differently than green tissue, which can be an attractive signal for moths. This is a good example of how morphology and trapping success are directly related.
🐜
Ants

Present in the catch of almost all species. Attracted by nectar along the outside of the pitcher.

🐛
Flies

Dominant in larger species like S. flava and S. leucophylla. Attracted by scent.

🐞
Beetles

Regularly found in larger pitchers, especially ground beetles following the nectar.

🦋
Moths & Butterflies

Especially with S. leucophylla. Only a small proportion of the total catch, but remarkably species-specific.

🐝
Bees & Bumblebees

Rarely caught and in very small numbers. No measurable effect on bee populations demonstrated.

🦟
Mosquitoes

Hardly caught by Sarracenia. Mosquitoes are better caught by Drosera (sundews).

Prey in Belgium and the Netherlands

Doorgeknippe Sarracenia flava beker vol met gevangen vliegen
🔬 Fig. 2. A cross-section of an S. flava pitcher from our greenhouse, filled with captured blowflies. Own capture, August 2020

In our climate zone, Sarracenia mainly catch flies, ants, and wasps, depending on the species and location. A question I often get: how many flies can such a trumpet pitcher plant actually catch?

It's difficult to give an exact number, but these plants have evolved over thousands of years and are very efficient at what they do. If the plant is outdoors or in an unheated greenhouse, the pitchers are often full by the end of summer, with as many as 100 large blowflies per pitcher being no exception.

Remarkably: even if there are several thousand carnivorous plants together, as in our greenhouse, almost all plants still catch well. There is apparently no depletion of the local insect supply at normal plant densities.

Catch in practice

Rough indications for a mature plant outdoors or in an unheated greenhouse, late summer:

~100
blowflies per pitcher possible for large species like S. flava
≈0
effect on local bee populations, bees are rarely caught. The flowers are pollinated by bumblebees and bees.
🦟 ✗
mosquitoes are hardly caught by Sarracenia
⚠️ Mosquitoes and carnivorous plants: We often hear: "I bought a carnivorous plant to combat mosquitoes." Sarracenia is not the right choice for that. Mosquitoes are hardly caught here. For mosquitoes, you'd be better off looking at Drosera (sundews) on a sunny windowsill, though the numbers remain modest.

See for yourself: a full pitcher up close

Below is a video of a cross-section of a Sarracenia flava pitcher from our greenhouse. These aren't small mosquitoes — these are large blowflies.

🎬 Video 1. A cross-section of a Sarracenia flava pitcher from the carnivorous plant shop's greenhouse. The pitcher is filled with captured blowflies — an illustration of how efficiently these plants catch prey, even with many plants placed close together.
Pollinator-prey conflict: How does a plant attract pollinators for its flowers and prey for its pitchers, without accidentally eating its own pollinators? With Sarracenia, this is cleverly resolved: the flowers appear early in spring, before the pitchers are fully active. By the time the pitchers are functioning optimally, the pollen has already been dispersed.

Want a trumpet pitcher plant in your garden?

Hardy Sarracenia are surprisingly easy to grow outdoors in Belgium and the Netherlands, and catch prey throughout the season. View our cultivated assortment.

View our Sarracenia range

References

  • Fish, D. (1976). Insect-plant relationships of the insectivorous pitcher plant Sarracenia minor. Florida Entomologist, 199–203.
  • Harvard Forest. (2020). Sarraceniaceae captures. Retrieved from https://harvardforest.fas.harvard.edu/sarraceniaceae-captures.
  • Heard, S. B. (1998). Capture rates of invertebrate prey by the pitcher plant, Sarracenia purpurea L. The American Midland Naturalist, 139(1), 79–89.
  • Horner, J. D. (2014). Phenology and pollinator-prey conflict in the carnivorous plant, Sarracenia alata. The American Midland Naturalist, 171(1), 153–156.
  • Jürgens, A., Sciligo, A., Witt, T., El-Sayed, A. M., & Suckling, D. M. (2012). Pollinator-prey conflict in carnivorous plants. Biological Reviews, 87(3), 602–615.
  • McPherson, S., & Schnell, D. E. (2011). Sarraceniaceae of North America. Redfern Natural History Productions.
  • Wray, D. L., & Brimley, C. S. (1943). The insect inquilines and victims of pitcher plants in North Carolina. Annals of the Entomological Society of America, 36(1), 128–137.

📸 What's in your pitchers?

Curious what your Sarracenia has caught by the end of summer? Cut open a pitcher and send your photo to killian@dupontflora.com, who knows, your catch might be featured in a future article!

0 comments

Leave a comment

Please note, comments need to be approved before they are published.

Winkelen op collectie

Verzamelaarshoek
Collector's corner

Verzamelaarshoek

Venus flytrap
Venusvliegenvanger close-up foto van val

Venus flytrap

Indoor beginner plants
Vleesetende planten in huis op de vensterbank

Indoor beginner plants

More meat-eaters
Vleesetende planten in pot op tafel in een zomerse tuin

More meat-eaters