Life cycle of a giant carnivorous caddisfly, Himalopsyche japonica (Morton) (Trichoptera: Rhyacophilidae), in the mountain streams of Nagano, Central Japan

Abstract

The life cycle of a giant carnivorous caddisfly,

Life Cycle of Himalopsyche japonica (Morton) (Trichoptera: Rhyacophilidae) in Two High Mountain Streams in Nagano, Central Japan

“…At my four study sites, most populations of H. japonica were univoltine ( Fig. 4; Tsuruishi, 2003). Some early developing non-overwintering larvae emerged in autumn in the two lower sites (half a year for generation) (Tsuruishi, 2003), and some late developing overwintering larvae did not emerge by that time and overwintered as pupae in Takinoyu Stream (1 1 / 2 year for generation) (Fig.…”

“…1). The water temperature regimes at both sites were similar (Tsuruishi, 2003). The minimum water temperature was 0°C from January to February (winter) and reached 18°C in August (summer).…”

“…The minimum water temperature was 0°C from January to February (winter) and reached 18°C in August (summer). Details of the study sites and annual water temperature fluctuations are described in Tsuruishi (2003). All larvae, prepupae, pupae, and emerged pupal cases from the surface of boulders which were lifted from the water in cascades and rapids were collected for about one hour with tweezers and hand-picking at both sites.…”

“…This species has a complex univoltine cycle and partly includes bivoltine populations in two mountain streams at about 1000 m a.s.l. in Japan (Tsuruishi, 2003). In these sites, adults emerged from April to September with three distinct peaks of emergence which occurred by different emergence periods of different overwinter stages, viz.…”

“…Himalopsyche japonica (Tsuruishi, 2003). This species has a complex univoltine cycle and partly includes bivoltine populations in two mountain streams at about 1000 m a.s.l.…”