Wasps Tamper with Plant Chemistry to Woo Mates

Join Our Community of Science Lovers!

On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.

A tiny wasp no bigger than a flea can change the chemistry of plants to help it land a mate, according to a new study. Results published online this week by the Proceedings of the National Academy of Sciences suggest that the gall wasp (Antistrophus rufus) alters the ratio of compounds within a plant's stem to attract members of the opposite sex.

Gall wasp larvae spend nine to 10 months developing within live plant stems that protect and nourish them. The presence of the wasps gives the plants a signature scent. John F. Tooker of the University of Illinois at Urbana-Champaign and his colleagues found that adult males, which emerge first, rely on olfaction to locate potential partners still encased in plant stems. Specifically, the males sniff out telltale differences in the ratio of two forms of so-called alpha pinenes and beta pinenes emanating from the plant. "If males find a stem with a 50-50 ratio they will move on," Tooker says. "If they find a stem with a 70-30 or a 100-0 ratio, they likely will stay and find females emerging from it." The wasps also demonstrated a preference for the same species of plant in which they matured. According to study co-author Lawrence Hanks, the findings show "that insects can influence plants for their own needs, using a substitute for sex pheromones."

Subscribe to Support Independent Journalism

Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.

When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.

Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber

Thank you,

Jeanna Bryner, Editor in Chief, Scientific American