Variation in flash speed of Japanese firefly,Luciola cruciata (Coleoptera: Lampyridae), identifies distinct southern “quick‐flash” population on Goto Islands,Japan

Luciola cruciata, a bioluminescent firefly endemic to Japan, communicates with species‐specific flashing patterns. Previous studies reported that flying males possess three distinct flashing frequencies: slow (4 s), intermediate (3 s) and fast (2 s). Our study focused on geographical variations in flashing patterns in the northwestern part of the Kyushu region of southern Japan (including its isolated islands) and their relationship to the mitochondrial COII region of firefly DNA. We found that “quick‐flash (1 s)” fireflies occur in the Goto Islands, at the western tip of Kyushu, and that, although they possess a unique haplotype, they do not differ much genetically from “fast‐flash” fireflies inhabiting mainland Kyushu. In contrast, although fireflies inhabiting the Tsushima and Iki Islands also possess a unique haplotype, their flashing patterns were the same (fast‐flash) as fireflies inhabiting mainland Kyushu. We determined that flash patterns of L. cruciata in Japan should be classified according to four flashing patterns: slow, intermediate, fast and quick.