Male reproductive polymorphism and form‐specific habitat utilization of the damselfly Mnais pruinosa (Zygoptera: Calopterygidae)

Abstract

Habitat utilization patterns were studied in damselfly males, Mnaispruinosa, which have two male forms with different reproductive behaviors. The 'esakii' (orange-winged males) were territorial around oviposition sites, while the 'strigata' (hyaline-winged males) were non-territorial, often sneaking into the esakii's territory or loitering on the foliage of vegetation along stream banks. The place in the stream in the study area where females frequently appeared was covered by reeds and had abundant oviposition sites. It was difficult for the territorial esakii to stay there because the crowded reeds prevented them from defending their territory and discovering the females. Furthermore, there was competition for the limited territorial space with another species, Mnais nawai. Strigata males concentrated in this place in direct proportion to the number of females. Females frequently mated with strigata males and probably deposited eggs fertilized by strigata sperm rather than esakii sperm. The density of strigata was higher than that of esakii in this study area. If the average reproductive success of esakii and strigata males is equal, this may indicate that the equilibrious point between the two male forms is biased toward strigata.

Expression of a costly, plastic secondary sexual trait is correlated with age and condition in a damselfly with two male morphs

“…Damselflies of the Mnais species group (Odonata: Calopterygidae) are polymorphic, males existing in orange‐ and clear‐winged forms ( Nomakuchi 1992; Tsubaki et al . 1997 ).…”

“…1997 ). The orange wing is probably a sexually selected signal, since females are clear‐winged and of the males, the orange‐winged morph is territorial, whereas clear‐winged males are usually non‐territorial ( Nomakuchi 1992; Tsubaki et al . 1997 ).…”

Competitive habitat utilization in the damselfly, Mnais nawai (Zygoptera: Calopterygidae) coexisting with a related species, Mnais pruinosa

“…In the damselfly, M. nawai, a population of the two male forms nawai (orange-winged males) and sahoi (paleorange-winged males), and one female form, nawai (paleorange-winged females), was seen near Fukuoka City, Japan (Nomakuchi 1992). The nawai males were territorial and the sahoi males were usually non-territorial in nature.…”

Smaller damselflies have better flight performance at lower body temperature: implications for microhabitat segregation of sympatricMnaisdamselflies

“…Males of both species hold territories within the same stretch of the river in most of Kinki region in central Japan. However, M. costalis were more abundant on the lower stream, while M. pruinosa were more abundant on the upper stream (Nomakuchi, 1992;Okuyama et al, 2013;Suzuki & Tamaishi, 1982). Measurement of canopy openness using hemispherical photographs with a fisheye converter revealed that M. costalis preferred sunny microhabitats while M. pruinosa preferred shady microhabitats (Okuyama et al, 2013).…”

“…Orange-winged males show territorial behaviors, defending dead semi-submerged logs or emergent plants into which females oviposit, and copulate with females on territories. Clear-winged males usually perch nearby orange-winged males' territorial sites, trying to intercept approaching females for copulation and oviposition (for M. costalis; Hayashi et al, 2004;Tsubaki, Hooper, & Siva-Jothy, 1997;for M. pruinosa;Nomakuchi, 1992;Nomakuchi, Higashi, & Maeda, 1988).…”