Weight Loading and Reproductive Status Affect the Flight Performance of Pieris napi Butterflies

Abstract

Weight-induced mobility reductions can have dramatic fitness consequences and winged animals are especially sensitive to the trade-off between mass and locomotion. Data on how natural weight fluctuations influence a flying insect's ability to take off are scarce. We therefore quantified take-off flight ability in Pieris napi butterflies in relation to reproductive status. Take-off flight ability (velocity and take-off angle) under suboptimal temperature conditions was recorded with a 3D-tracking camera system and was predicted to decrease with relatively larger weight loads. Our results show that relatively larger weight loads generally reduce flight speed in male butterflies and lower take-off angles in females. However, despite having a lower wing loading, mated male butterflies flew slower than unmated males. Our study suggests that retention of weight loads associated with reproduction impairs insect flight performance.

Wing shape patterns among urban, suburban, and rural populations ofIschnura elegans(Odonata: Coenagrionidae)

“…However, after becoming sexually mature, females only return to breeding sites when they are receptive (Corbet, 1999) and undergo stronger selective pressure to forage (Anholt, 1992), whereas males tend to stay close to breeding sites in order to find a mate (Beirinckx, Van Gossum, Lajeunesse, & Forbes, 2006;Corbet, 1999), therefore females may need to be more dispersive than males (Beirinckx et al, 2006). Moreover, females can also show impaired locomotor performance once they become gravid (Carlson, McGinley, & Rowe, 2014;Olsson, Shine, & Bak-Olsson, 2000;Samietz & Köhler, 2012;Shine, 2003) and in flying organisms, pregnancy has shown to affect take-off negatively (Almbro & Kullberg, 2012;Lee, Witter, Cuthill, & Goldsmith, 1996;Veasey, Houston, & Metcalfe, 2001). In such case, the larger, longer, and narrower wing pattern found in females could be of aid for long-distance dispersal, since the angular velocity increases towards the wing tip in flapping wings, notably in petiolated wings where the velocity gradient from base to tip is more pronounced (Bomphrey et al, 2016;Dudley, 2000), thus providing more lift per wingbeat (Bomphrey et al, 2016).…”

Influences of Parental Care and Food Deprivation on Regulation of Body Mass in a Burying Beetle

“…Parents that have completed a breeding attempt might be expected to return to a body mass optimal for locating another reproductive opportunity, regardless of earlier nutritional environments. Excess mass in burying beetles might decrease flight efficiency and maneuverability as in butterflies (Marden & Chai ; Almbro & Kullberg ) and birds (Boyle et al. ).…”

Measuring Intraspecific Variation in Flight-Related Morphology of Monarch Butterflies (Danaus plexippus): Which Sex Has the Best Flying Gear?

“…Of the computed flight performance parameters, wing loading is perhaps the most critical, and here we found a key difference between male and female monarchs that may help explain their different migration success rates; female wing loading was significantly lower than that of males (about 7% lower). Wing loading scores are indicative of how much work the wings must perform to carry the weight of the insect, and lower wing loading means it would take less energy to fly [32][33][34]. This pattern may explain both the higher success rates of female monarchs over males in reaching the overwintering sites [7,8] and the longer flight times of females over males in captive flight mill studies [6].…”