A potential presence of cryptic species in the Asian common dark firefly Lucidina biplagiata

The presence of two morphological forms in the Asian dark firefly Lucidina biplagiata (the Japanese name: Oba-botaru) in Japan was suggested by Dr. Sakyo Kanda in 1935, but they have long been considered to be the morphotypes of a single species. In this study, we examined the genetic variations and temporal emergence of Oba-botaru specimens at a single locality in Aichi, Japan. Phylogenetic analyses of mitochondrial and nuclear markers revealed two distinct lineages within L. biplagiata. Adult emergence patterns differed between the two sympatric groups. We found that the mode of the pronotal color patterns could be largely distinguished between the two groups, and also between bimodal emergence. Preliminary mating experiments showed that males and females from the two genetic groups did not mate in captivity. These results strongly support the existence of two sympatric, reproductively isolated species-level lineages within L. biplagiata.