Scientists often visit remote forests, mountains, and islands in search of undiscovered species. But in a surprising development, researchers at Kyushu University have discovered that a previously unknown ladybug lives in pine trees right near the university’s campus.
The name of the newly identified species is Parastesolus pinicolawas discovered by the Kyushu University Hakozaki satellite. This finding was reported in Entomology Journal of the National Museum of Prague The study grew out of a three-year project investigating the taxonomy of stesolini, a group of small ladybugs that feed on spider mites. This study is the first large-scale investigation of this group in Japan in more than 50 years.
New species of beetle discovered on campus
“I knew that this ladybug family often lives in pine trees. Black pine trees grow in Hakozaki Satellite, so I decided to go there and find a new species,” explains Ryota Seki, lead author of the study and a doctoral student in the Entomology Laboratory at the Graduate School of Biological Resources and Environmental Sciences. “Usually insect collectors don’t pay much attention to pine trees, which is probably why scientists have overlooked this species for so long.”
The newly discovered insect is a small black beetle, just over a millimeter long. Its scientific name is Parastesolus pinicolameaning “pine inhabitant”, reflecting the habitat in which it is found.
Why these tiny ladybugs are difficult to identify
According to Seki, these insects are poorly studied because it is very difficult to distinguish one species from another.
“These little black ladybugs are very difficult to identify, so they haven’t been studied much,” says Professor Seki. “They are barely larger than a grain of sand and all look the same. You can’t tell the species apart unless you dissect them and examine their reproductive organs under a microscope. Because of this difficulty, there have been many misidentifications in past records.”
To clear up years of confusion, the research team carefully examined about 1,700 specimens. Their research revealed that it is common in Japan. japonicus It’s actually the same species Stethorus siphonulusfound in a wide geographical range from China to Southeast Asia.
Second new species discovered
This review brought another surprise. The researchers also identified and named a second previously unknown species in Hokkaido. Stesolus Gay.
Mr. Seki chose this name in honor of his grandmother, Takako Otsuki, who had been interested in entomology since childhood.
“Standardizing these names is important so we can share data and research with other countries in Asia,” Seki points out. “This reveals that this is a species that is widely distributed from tropical to temperate regions of Japan.”
Biodiversity hidden in everyday places
For Associate Professor Munetoshi Maruyama of the Kyushu University Museum, who oversaw the project, this discovery served as a reminder that much of nature in our immediate environment remains unnoticed.
“People rarely notice these tiny insects. But as our study showed, unknown species live right next to us, even in cities and university campuses,” says Maruyama. “These ‘tiny’ insects support our ecosystem, and we hope this discovery will spark an interest in the diverse and fascinating world that exists beneath our feet.”

