Discussion
Kusaoke et al. (8) followed Ohba’s criteria (small morph, body length 5 to 6 mm, below 800 m altitude) (7) and suggested the possibility that almost all the specimens collected by Mitsuishi (3–6) may belong to the large morph. However, the present article confirmed the existence of the two morphs showing discontinuous allometric scaling relationship.
Kusaoke et al. (8) found no genetic difference between the two morphs at Mt. Daisen, Tottori Prefecture. Moreover, Suzuki (9) and Hiyori et al. (10) reported no genetic difference between them in Nagano Prefecture where Mitsuishi (3–6) collected the specimens. Therefore, in L . parvula , the difference in allometry between the two morphs with genetic similarity may be connected with the morphological plasticity of this species.
There are few studies on intrasexual dimorphism in lampyrid species except for Wu et al. (15), who documented two distinct male morphs with different mating strategies in Absconditacerata (previously named Luciola cerata ) in Taiwan. Further detailed molecular phylogenetic and morphological studies will be necessary to confirm the male dimorphism of L . parvulathroughout Japan.
In conclusion, the present article strongly recommends that allometric analysis should be used to identify the two morphs in this species in future studies.