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

• Published in: European journal of entomology Vol. 113; no. 1; pp. 571 - 578
• Main Authors: NEVE, Gabriel, HALL, Casey
• Format: Journal Article
• Language: English
• Published: Ceske Budejovice Institute of Entomology 01-01-2016; Czech Entomological Society; Institute of Entomology, Biology Centre, Czech Academy of Science
• Subjects: allometry; Biodiversity and Ecology; Body temperature; Butterflies & moths; Environmental Sciences; Habitats; Heat; Hesperiidae; infra red thermometer; Lepidoptera; Lycaenidae; Meropes; Nymphalidae; Papilionidae; physical constraint; Pieridae; Studies; Thorax; thorax flight temperature; warming-up rate; wing loading; Papilionidae; physical constraint; allometry; Hesperiidae; Lepidoptera; thorax flight temperature; Pieridae; infra red thermometer; warming-up rate; Nymphalidae; wing loading; Lycaenidae
• ISSN: 1210-5759; 1802-8829
• DOI: 10.14411/eje.2016.077

Thermal requirements for flight in butterflies is determined by a combination of external factors, behaviour and physical constraints. Thorax temperature of 152 butterflies was monitored with an infra-red thermometer in controlled laboratory conditions. The temperature at take-off varied from 13.4°C, for a female Heteronympha merope to 46.3°C, for a female Junonia villida. Heteronympha merope, an understorey species, had the lowest recorded take-off temperatures, with females flying at a much lower thorax temperatures than males. Among the tested butterfly species, warming-up rate was positively correlated with take-off temperature and negatively with body mass. Wing loading is a major variable in determining the thorax flight temperature. Butterflies with the highest wing-loadings experienced the highest thorax temperatures at take-off. A notable exception to this rule is Trapezites symmomus, the only Hesperiidae of our data set, which had thorax flight temperatures of 31.5°C and 34.5°C, well within the range of the observed butterflies, despite a wing load ca. five times higher. The high thorax temperature recorded in J. villida is probably linked to its high flight speed. The results highlight the importance of physical constraints such as body size on the thermal requirements for flight across a range of butterfly species.