Activity in Heodes virgaureae (Lep., Lycaenidae) in relation to air temperature, solar radiation, and time of day

Abstract

The degree of activity of H. virgaureae in the field is largely dependent on air temperature, solar radiation, and wind velocity. Solar radiation increases body temperature above ambient. The butterfly orientates its back towards the sun and exposes the dorsal surface of the wings. At high temperatures they close the wings thereby minimizing the surface exposed to the sun. The optimal body temperature lies around 35°C as was indicated by laboratory experiments. In cloudy and cool to fairly warm conditions the butterfly is inactive. In sunshine the butterfly basks at low radiation intensities or low air temperatures while feeding (in males also flying) predominates at full sunshine or very high air temperatures (around 30°C). Males fly 5-10 times as much as females. A change from unfavourable to favourable weather is followed by an immediate increase in activity of the butterfly, which enables the butterfly to utilize short periods of sunshine.

Variation of thorax flight temperature among twenty Australian butterflies (Lepidoptera: Papilionidae, Nymphalidae, Pieridae, Hesperiidae, Lycaenidae)

“…In Heteronympha merope, females may fl y at a much lower thorax temperature than males. This sex difference is unusual, as females need a higher thorax temperature for fl ight than males in Colias philodice (Kingsolver, 1983) and in Thymelicus lineola (Pivnick & McNeil, 1986), whereas no difference were found in Heo des virgaureae (Douwes, 1976). Unlike these species, H. merope shows mainly disjunct population peaks for males and females, with males most abundant in spring and females in autumn (pers.…”

Take-off performance under optimal and suboptimal thermal conditions in the butterfly Pararge aegeria

“…Mechanical power output of flight muscles increases with body temperature, and is maximal near species-specific muscle temperatures characteristic of free flight (Stevenson and Josephson 1990;Lehmann 1999;Dudley 2000). For several temperate zone butter- (Douwes 1976;Rutowski et al 1994;Dreisig 1995)]. In Colias butterflies (Tsuji et al 1986) and honeybees (Esch 1976), flight speed and wing beat frequency increased with increasing thoracic temperature.…”

Movement of two grassland butterflies in the same habitat network: the role of adult resources and size of the study area

“…L. and possibly Milium L.; Henriksen & Kreutzer, 1982). The larvae of the scarce copper feed on Rumex acetosella L. or Rumex acetosa L. (Douwes, 1976).…”