Mobility affects copulation and oviposition dynamics in Pieris brassicae in seminatural cages

Abstract

When, how often and for how long organisms mate can have strong consequences for individual fitness and are crucial aspects of evolutionary ecology. Such determinants are likely to be of even greater importance in monandrous species and species with short adult life stages. Previous work suggests that mobility, a key dispersal-related trait, may affect the dynamics of copulations, but few studies have investigated the impact of individual mobility on mating latency, copulation duration and oviposition latency simultaneously. In this paper, we monitored the copulation dynamics of 40 males and 40 females, as well as the oviposition dynamics of the females of the Large White butterfly Pieris brassicae, a facultative long-distance disperser butterfly. Individuals from a breeding were selected to create a uniform distribution of mobility and we recorded the timing, number and duration of all copulations in a semiexperimental system. We showed that mobility, measured as the time spent in flight under stressful conditions (a proxy of dispersal tendency), correlates with all aspects of copulation dynamics: mobile males and females mated earlier and for shorter periods than less mobile individuals. In turn, late mating females increased the time between copulation and oviposition. These results feed the previously described mobility syndrome of P. brassicae, involving morphological and physiological characters, with life-history traits. We suggest that the reduction of mating latency and copulation duration has an adaptive value in dispersing individuals, as their life expectancy might be shorter than that of sedentary individuals.

A Review of the Phenotypic Traits Associated with Insect Dispersal Polymorphism, and Experimental Designs for Sorting out Resident and Disperser Phenotypes

“…For instance, the aphid Tuberculatus paiki, which is a good disperser, has a lower wing loading as compared with Tuberculatus quercicola (low level of dispersal in comparison to T. paiki); the higher body volume of T. quercicola most probably contribute to explaining the higher number embryos measured in this species [139]. Within insect species, the flight-reproduction trade-off has been reported from both wing-polymorphic [62,[140][141][142] and wing-monomorphic [81,82,143,144] insects, but this pattern has also been refuted in other studies [145]. In the cricket Gryllus firmus, which represents one of the model insect often used for running investigations on dispersal costs, small-winged females produce 60% more eggs than their large-winged counterparts over a period of six weeks [146,147].…”

“…A dispersal-reproduction trade-off also exists in wing-dimorphic insects, with mating latency (age at reproduction of males and females) and duration of copulation being affected by dispersal capacities. In the butterfly Pieris brassicae, the measured values for these two reproductive parameters are shorter in individuals having a high mobility (dispersers; [82,142]) as compared with those of low mobility [81]. In males of T. castaneum selected for higher mobility, copulation durations were shorter, and these individuals also exhibited a lower stimulation of the females during mating [150], and had lower mating success [151].…”

“…Finally, it is also worth mentioning that other experimental systems can be used for separating resident from disperser individuals. For example, the assessment of the flight endurance of the insects subjected to stressful (hostile) conditions has been measured with a vortex system in butterflies, [80,81]. In this procedure, butterflies were assessed individually for mobility performance in a 250 × 100 × 100 mm plastic container; they were acclimated for 30 s before being vortexed for 60 s at 25 • C. The time spent flying for each individual during this stressful (hostile) minute was recorded, and represented a good correlate of dispersal ability, i.e., dispersers were characterized with good abilities to maintain flight in these hostile conditions, while residents had a lower flying performance [82].…”

Ecology of female mating failure/lifelong virginity: a review of causal mechanisms in insects and arachnids

“…The fitness of females often increases with the number of copulations or the quality of the male partner (Puurtinen & Fromhage, ; Suzaki et al., ). Nevertheless, the fitness increments of first (virginal) mating generally outweigh increments of subsequent (polyandrous) copulations (Kokko & Mappes, ; Larranaga et al., ). Due to predominance of anisogamy and asymmetric reproductive investment (Bateman–Trivers paradigm: promiscuous males with cheap sperm vs. coy females carrying costly eggs), rates of lifelong virginity are typically higher in males than in females (Janicke & Morrow, ) .…”

A Review on Dispersal Polymorphism in Wing-Dimorphic, Mono-Morphic, Wingless, and Range-Expanding Insects, and Experimental Designs for Sorting out Resident and Disperser Phenotypes

“…Finally, the assessment of the flight endurance of the insects subjected to stressful conditions has been measured with a vortex system in butterflies, [80][81]. In this procedure, butterflies are assessed individually for mobility performance in a 250 x 100 x 100 mm plastic container; they were acclimated for 30 s before being vortexed for 60 s at 25 °C.…”