New species of fruit fly discovered by Hokkaido University

A research group led by Associate Professor Toru Katoh of the Faculty of Science at Hokkaido University, has discovered a new species of fruit fly in various locations of Hokkaido, including the Tomakomai Experimental Forest, Southern Management Office, Forest Research Station, Field Science Center for Northern Biosphere, Hokkaido University, and the "Keiteki-no-Mori" forest on the Sapporo campus, and named it Hokudai Fruit Fly. It was recorded as a new species with the scientific name Lordiphosa yuktopakina (yuktopakina refers to Japanese spurge in the Ainu language). Through an integrative taxonomic approach, the group revealed that it diverged from L. collinella into a distinct species only about a hundred thousand years ago. The results were published online in Entomological Science.

L. yuktopakina possesses a morphology very similar to L. collinella, which is widely distributed across East Asia. Both are collected together in various parts of Hokkaido. L. collinella is collected from various herbs, primarily spring ephemerals such as Anemone flaccida. L. yuktopakina is frequently collected from communities of Japanese spurge (Pachysandra terminalis), an evergreen shrub in the boxwood family.

The research group used an integrated taxonomic approach in this study. Specifically, they performed geographical distribution surveys, morphological comparisons, crossing experiments, karyotype analysis, DNA analysis, and reproductive ecology surveys, aiming to clarify the evolutionary path of L. yuktopakina by integrating and verifying the obtained results.

From this it was revealed that L. yuktopakina, in addition to specializing in Japanese spurge as a food source, possesses characteristics suited to utilizing its tough leaves and stems, such as sharp oviscapt valves (ovipositors) in adult females and relatively developed parts of the larval cephalopharyngeal skeleton. Furthermore, results from DNA analysis and crossing experiments indicated that L. yuktopakina diverged from L. collinella into a separate species only about a hundred thousand years ago.

It became clear that L. yuktopakina adapted to the utilization of the tough leaves and stems of Japanese spurge while completing speciation in a short period of time. Since the genomic information of L. collinella has already been made public, it is expected that once the genomic information of L. yuktopakina is decoded in the future, comparing the information of both species will lead to research exploring the genetic basis of speciation.

Journal Information
Publication: Entomological Science
Title: Recent speciation with host change in the genus Lordiphosa Basden (Diptera: Drosophilidae) breeding on decayed herbaceous plants, with description of a new species based on integrative taxonomy
DOI: 10.1111/ens.70005