Effects of within-generation thermal history on flight performance ofCeratitis capitata: colder is better

Abstract

The influence of thermal history on temperature-dependent flight performance was investigated in an invasive agricultural pest insect, Ceratitis capitata (Diptera: Tephritidae). Flies were exposed to one of four developmental acclimation temperatures (T acc : 15, 20, 25, 30°C) during their pupal stage and tested at these temperatures (T test ) as adults using a full-factorial study design. Major factors influencing flight performance included sex, body mass, T test and the interaction between T test and T acc . Successful flight performance increased with increasing T test across all acclimation groups (from 10% at 15°C to 77% at 30°C). Although T acc did not affect flight performance independently, it did have a significant interaction effect with T test . Multiple comparisons showed that flies which had been acclimated to 15°C and 20°C performed better than those acclimated to 25°C and 30°C when tested at cold temperatures, but warm-acclimated flies did not outperform cold-acclimated flies at warmer temperatures. This provides partial support for the 'colder is better' hypothesis. To explain these results, several flight-related traits were examined to determine whether T acc influenced flight performance as a consequence of changes in body or wing morphology, whole-animal metabolic rate or cytochrome c oxidase enzyme activity. Although significant effects of T acc could be detected in several of the traits examined, with an emphasis on sex-related differences, increased flight performance could not be explained solely on the basis of changes in any of these traits. Overall, these results are important for understanding dispersal physiology despite the fact that the mechanisms of acclimation-related changes in flight performance remain unresolved.

Investigating population differentiation in a major African agricultural pest: evidence from geometric morphometrics and connectivity suggests high invasion potential

“…Sexual dimorphism in tephritids may be linked to courtship behaviour as males use wing movements (among other stimuli) to attract the attention of females (Wicker‐Thomas ) or sex‐related differences in dispersal or flight ability (Sivinski & Dodson ; Esterhuizen et al . ). After separation of males and females, however, there was still no differentiation between sampling localities based on wing shape.…”

“…However, in nine species in the Drosophila melanogaster subgroup sexual dimorphism based on wing shape was investigated and all nine species exhibited sexual dimorphism (Gidaszewski et al 2009). Sexual dimorphism in tephritids may be linked to courtship behaviour as males use wing movements (among other stimuli) to attract the attention of females (Wicker-Thomas 2007) or sex-related differences in dispersal or flight ability (Sivinski & Dodson 1992;Esterhuizen et al 2014). After separation of males and females, however, there was still no differentiation between sampling localities based on wing shape.…”

Thermal ecological physiology of native and invasive frog species: do invaders perform better?

“…Our findings are in agreement with previous studies showing that African clawed frogs inhabiting Europe have the ability to compensate for the effects of lower temperatures by enhancing their swimming performance (Wilson et al ., 2000). Moreover, our results are in accordance with the ‘colder is better’ hypothesis, which predicts that organisms acclimated to low temperatures could achieve greater locomotor performance than others held in warm conditions (Deere and Chown, 2006; Frazier et al ., 2008; Esterhuizen et al ., 2014). …”

Cold treatment enhances low‐temperature flight performance in false codling moth, Thaumatotibia leucotreta (Lepidoptera: Tortricidae)

“…Furthermore, since insects' tolerance to environmental conditions depends on the timing and duration of their exposure to prior environmental stress (Sgrò et al ., ), thermal history in SIT programmes may affect competition between field and sterile mass‐reared individuals, since multiple behaviour and locomotor performance traits can be strongly modified by thermal history ( e.g . Kristensen et al ., ; Chidawanyika & Terblanche, ; Esterhuizen et al ., ). Because of the complex range of responses to thermal stress, further investigation is needed to provide insight into responses of field‐released insects and how they might be manipulated (Terblanche, ).…”