title: The First Finding of Six Instars of Larvae in Heteroptera and the Negative Correlation between Precipitation and Number of Individuals Collected in Sea Skaters of Halobates (Heteroptera: Gerridae).
abstract: This study, conducted during a scientific cruise, MR15-04, aims, first, to examine species and larval/adult components ofHalobates(Heteroptera: Gerridae) inhabiting the tropical Indian Ocean of 4°00' S-7°00' S, 101°00' E-103°00' E and, second, to examine the correlative relationship between precipitation just before collection and the number of sea skaters collected in November and December 2015. Near Sumatra (50 km south-west), larvae and adults of four species ofHalobates(Halobates germanesWhite, 1883;Halobates micansEschscholtz, 1822;Halobates princepsWhite, 1883; undescribed species:Halobatessp.) were collected. Adults of an undescribed species had about a 5 mm long body in a gourd-like shape. One male adult specimen ofH. princepswas collected. Body length, body width, and head width was measured in all specimens ofHalobates. Six larval stages were detected in all three species of sea skaters as the first finding for Heteropteran insects. There was a negative correlation between amount of precipitation for 19 h before collection and the number ofHalobatesindividuals collected by the neuston net. Death or (positive or passive) sinking by sea skaters could be due to occasional rain fall on the sea surface.
authors.affiliation: Laboratory of Environmental Physiology, Graduate School of Integrated Sciences and Arts, Kochi University, Kochi 780-8520, Japan. haratets@kochi-u.ac.jp.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Harada
authors.affiliation: Laboratory of Environmental Physiology, Graduate School of Integrated Sciences and Arts, Kochi University, Kochi 780-8520, Japan. B15m6b21@s.kochi-u.ac.jp.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Furuki
authors.affiliation: Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan. wakamura.tomoko.5v@kyoto-u.ac.jp.
authors.forename: Wataru
authors.initials: W
authors.lastname: Ohoka
authors.affiliation: Laboratory of Environmental Physiology, Graduate School of Integrated Sciences and Arts, Kochi University, Kochi 780-8520, Japan. b13m6b17@s.kochi-u.ac.jp.
authors.forename: Noritomo
authors.initials: N
authors.lastname: Umamoto
authors.affiliation: Laboratory of Science Education, Graduate School of Integrated Sciences and Arts, Kochi University, Kochi 780-8520, Japan. Mit-na@kochi-u.ac.jp.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Nakajo
authors.affiliation: Faculty of General Education, Tokyo Denki University, Tokyo 120-8551, Japan. 20445@ms.dendai.ac.jp.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Katagiri
keywords: near Sumatra; negative correlation between precipitation and number of sea skaters; sea skaters; six instars as larval stages; undescribed species