Six new species of insects have been discovered in the Fujian province side of Wuyishan National Park, according to the park's management bureau.

The park stretches across Fujian and Jiangxi provinces.

The discovery is part of efforts of a three-year background survey of biological resources within the park, which began in April 2021 and has yet to be completed.

The result, made by three research teams invited to the survey, has uncovered new species of mountain midge and caddisfly.

Some of the results have been published in the Journal of Insects.

Researchers from the School of Life Sciences at Nanjing Normal University and Jiangsu University of Science and Technology discovered two species — Deuterophlebia wuyiensis and Deuterophlebia acutirhina — in the park.

Zheng Xuhongyi, a researcher from NNU, said the discovery means that the park still maintains extremely valuable, pristine, non-disturbing and pollution-free stream habitats that contain a large number of animal and plant species to be studied.

"Our study for the first time obtained color photos of live mountain midge females and the genetic sequences of this family, which enhances the understanding of the family's diversity and life history," Zheng said.

Mountain midges are a mysterious and rare group whose habits and species diversity are little known, Zheng said.

Previously, only eight species of the group have been reported in countries including Mongolia, Russia, Japan and India, Zheng said.

According to previous literature, the larvae live only in clean torrent environments and their short life spans led to the rarity of specimens, he said.

The rare family plays a key role in the evolution of dipteran insects, or flying insects. It is considered to be the oldest branch in the latest study. However, as the shortest-lived and most primitive dipteran insect, a Chinese species of this family has only been collected in a small number of specimens in the Xinjiang Uygur autonomous region and briefly described, he said.

Last March, Zheng and his team found mountain midges during a survey of aquatic insects in the park. Near Tongmu village, in the hinterland of the park, he collected many larvae and pupae of this family on the rocks in the rapids area of a stream. By putting the stones with pupae on them in an enclosure arranged in the rapids, he finally captured two females with lost wings crawling underwater when he checked the enclosures the following morning.

"We took some photos, which may be the first in color of a live female adult in the family," he said.

After dissecting and studying the pupae, Zheng's team found they showed significant morphological differences from foreign reported species, mainly in the head shape, antennae, legs and genitals, which made it clear that they are a previously undiscovered species, he said.

Song Chao from Taizhou University in Zhejiang province and his team found two new species — Microtendipes bimaculatus and Microtendipes wuyiensis — in the park in March and April 2021.

Song said that they used lamp lures to collect specimens at night. Then they compared chest stains, leg spots and genital segments with previous species, which turned out to be quite different. DNA barcoding technology also helped show that the sequence of the species was genetically distant from other species.

"They are a new species morphologically and molecularly," he said.

The Wuyishan National Park, which is known for its rich insect diversity, has earned the reputation as an "insect kingdom". With the discovery of these six new species of insects, the park's record of insect species has been enriched, the park's management bureau said.

Yang Jie contributed to this story.