Spiders Enjoy the Occasional Vegetarian Meal

A jumping spider covered in pollen from a hibiscus. Image credit: © Nick Hobgood, University of South Pacific

Spiders eat more than the flies they snare in their webs. While we often imagine spiders as carnivorous predators, their diets are more diverse. Sometimes they eat fish. And, according to a new report in Journal of Arachnology, some arachnids are also more than willing to partake in vegetarian meals.

For the study, the team, led by biologist Martin Nyffeler at the University of Basel in Switzerland, collected 95 pre-existing reports in scientific literature of spiders eating plants. At least 10 families of spiders, from every continent but Antarctica, have been observed eating some kind of plant matter.

The jumping spider Bagheera kiplingi in Mexico eating a Beltian body, a leaf tip found on acacia plants. Image Credit: © Robert L. Curry, Villanova University

A concurrent study by Nyffeler in the journal PECKHAMIA focuses just on jumping spiders, the most prominent spider group that engages in this behavior. A total of 60 percent of the plant-eating events documented in the Arachnology study came from jumping spiders. And most of the reports of spiders eating plants came from warmer areas of the globe.

While the Central American jumping spider Bagheera kiplingi subsists on an almost entirely vegetarian diet, most spiders enjoy plant meals more sparingly. Some feed on nectar, some eat honeydew, while others collect pollen (like the jumping spider covered in pollen from a hibiscus, pictured in the first image above) in addition to eating insects. This could be an adaptation to allow spiders to survive when insects are scarce, or be a nutritional supplement. It’s possible that a larger number of spider species supplement their diets with the occasional vegetarian meal, but further research is necessary.