Helioscirtus moseri Saussure, 1884

Helioscirtus moseri Saussure, 1884 View in CoL

Figs 16–20, 23.

MATERIAL. Southern Kazakhstan, the rocky desert in the Charyn River Valley, ca 20 km north of Chundzha (=Shinzha), 43.7153° N, 79.4175° E, 24.VI.2024, in the same biotope with S. savignyi , signals of six males were recorded at 40–42 °C GoogleMaps .

SONGS. While singing, the male periodically flies up to a height of about a meter and lands near the takeoff point. Singing males stay in rocky or sandy areas devoid of vegetation ( Figs 23–24). The number of males at the studied location was very high, so their songs usually overlapped, forming an unceasing chorus.

The male calling song is an echeme produced during flight display and followed by low-amplitude syllable or, maybe, several merged syllables produced by stridulatory movements of the hind legs immediately after landing ( Figs 16–20). Sometimes these syllables are inaudible and, apparently, absent. The song repetition period usually averages 3–5 s and only occasionally reaches 7–9 s. Duration of an echeme produced by wings is about 0.8– 1.1 s, syllable repetition period in it is 18–19 ms in our recordings. The gap between the parts of a song produced during the flight and on the ground averages 90–180 ms, duration of the part produced on the ground is 100–240 ms.

REMARKS. Bey-Bienko and Mishchenko [1951: 635] points out that some of the longitudinal veins of the hind wings in species of Helioscirtus Saussure, 1884 are thickened, which is typical of species that produce signals in flight. Very brief description of the song of H. moseri from Northeastern China illustrated by only one oscillogram was published by Xi et al. [1992]. As far as can be judged, the signals of males from Kazakhstan and China are very similar.