Life History of an Endangered Marine InsectHalovelia septentrionalisEsaki (Hemiptera: Veliidae)

Abstract

Halovelia septentrionalis Esaki is one of the endangered marine water striders found along the Japanese coast. It is of primary importance to investigate its life history in the field so as to develop conservation measures as well as to understand how this species has adapted to marine environments. We studied its life history in Misaki on the southern part of the Miura Peninsular near Tokyo, ca. 35 ∘ N, probably the northernmost locality not only for H. septentrionalis but also for any Halovelia species, most of which are found in warm tropical or subtropical waters. The southern part of the Miura Peninsular has jagged coastlines with deep inner bays. Adults and nymphs were found skating along the rocky shore of inner bays with overhanging vegetation nearby. This species appeared to have at least 2 generations a year and to overwinter in the adult stage. We discussed its overwintering strategy in comparison to those of two other Japanese marine water striders.

A unique new species of halophilous water strider of the genus Aquarius Schellenberg (Hemiptera: Gerridae: Gerrinae) endemic to Omura Bay, Nagasaki, Japan

“…In 2016, as a part of the Super Science High School (supported by the Japan Science and Technology Agency) programmes improving biology education and research, we initiated a project to survey detailed distributional patterns and ecology of coastal marine water striders; namely Asclepios shiranui (Esaki), Halobates japonicus Esaki, and Halobates matsumurai Esaki (Gerridae: Halobatinae); and the riffle bug Halovelia septentrionalis Esaki (Hemiptera: Veliidae: Haloveliinae). These are all designated as endangered or vulnerable by the national and/or local governments (Ikawa and Nakazawa 2015), but our observations suggested that these species were exceptionally abundant within Omura Bay and its adjacent coastline. The fauna of the marine water strider and riffle bug in the bay was previously reported by Hayashi and Miyamoto (2003), who confirmed Asclepios shiranui and Halovelia septentrionalis at only one locality (site 4).…”