The next time you post a nature photo online, you might be contributing to a major scientific breakthrough – just as several citizen scientists did when they helped discover the wasp Eupelmus curvator in Japan.
When a series of photos appeared on Twitter (now X) showing an iridescent wasp laying eggs on a praying mantis egg case, researchers from the
Kyushu University Museum realised they weren't looking at a common garden insect. Instead, they were witnessing a species never before seen in Japan:
Eupelmus curvator.
“The discovery was made possible through social media,” said Taisuke Kawano, the lead researcher and a specialist in eupelmid wasps at the Kyushu University Museum. “It all started with a post by a general user who shared a photo capturing a wasp emerging from a mantis egg case. A colleague of mine noticed the post and forwarded it to me via direct message.”
The wasp is the first record of Eupelmus curvator in Japan, a species previously known only to inhabit China. Perhaps more significantly, the recent study provided the first formal scientific description of the male of the species, which had remained a mystery until now.
A Rare Egg Hunter
“Eupelmus curvator is particularly interesting because it parasitises the egg cases of praying mantises,” Kawano explained. “While some other genera in Eupelmidae are specialised egg parasitoids, most species of Eupelmus attack larvae or pupae of other insects, and only very few are known to develop inside mantis oothecae. This makes Eupelmus curvator a rather unusual and biologically intriguing species.”
The researchers confirmed that the wasp targets the Narrow-winged Mantis (Tenodera angustipennis), turning the mantis’ future offspring into a nursery for its own young. In one case, a single mantis egg case collected in Fukuoka yielded 77 wasps and only a few surviving mantis nymphs.
Digital Collecting: The Future of Citizen Science
In the spring of 2018 and again in 2021, citizen scientists and nature enthusiasts posted images and videos of the wasps' behaviour on Twitter. Through direct communication on the platform, these users sent specimens to Kawano for identification.
“Social media is becoming an increasingly important tool in citizen science,” Kawano said. “One of its greatest strengths is that it effectively increases the number of ‘eyes in the field.’ These observations often come from places and times that researchers would not normally be able to cover. When particularly interesting records appear, we can contact observers directly via social media, and in some cases obtain specimens for further study.”
To document the tiny find - females measure only about 2.2 to 3.2 mm excluding the ovipositor - the team used advanced macro photography and focus stacking technology to create hyper-detailed images of the wasp's anatomy.
Science in Your Backyard
The discovery suggests that even in well-studied regions like Japan, there is a wealth of biodiversity to be uncovered. The key, according to Kawano, is that scientists are now finding it in new ways.
“One of the most exciting aspects is how social media is changing the way we conduct research,” Kawano noted. “The social media platforms allow researchers to encounter observations that would otherwise remain unnoticed, effectively transforming everyday posts into valuable scientific data.”
As for his own social media habits? Kawano admits the line between work and leisure has blurred. “Personally, I sometimes joke that even when I am browsing social media, I am actually working,” he said. “And it is sometimes true... though not always.”