Fuelling flight in a parasitic wasp: which energetic substrate to use?

Abstract

1. Flight is an energy-demanding behaviour in insects. In parasitic wasps, strategies of nutrient acquisition and allocation, resulting life-history trade-offs and relationships with foraging strategies and resource availability have received much attention. However, despite the ecological importance of dispersal between host and food patches, and the great impact energy diverted to flight should have on lifetime reproductive success, the eco-physiology of flight in parasitoids is poorly understood.2. The objective of this study is to (i) identify the energetic resources used to fuel flight, and (ii) relate nutrient type and rate of utilisation to selective pressures in terms of resource availability posed by the environment.3. Using a flight mill and biochemical assays, we compared flight performance and nutrient dynamics during flight between two reproductive modes of the parasitoid Venturia canescens Gravenhorst, which is known to thrive preferentially in contrasted environments (i.e. natural vs. anthropogenic habitat), differing notably in host and food distribution. 4. Biochemical analyses of different nutrient types showed that glycogen is the flight fuel used by this species, yet no significant differences in its dynamics in flight were found between the two reproductive modes.5. Results suggest that both glycogen quantity and flight performance are related to the diverging ecological conditions experienced by thelytokous and arrhenotokous strains.

Insects and incest: sib-mating tolerance in natural populations of a parasitoid wasp

“…The proportion of diploid males further corresponds to that expected when sex ratios are equal (Fauvergue et al, 2015). Field and laboratory studies further revealed that adult females are good dispersers, with a flight velocity estimated at 0.2 m.s -1 (Schneider et al, 2002;Desouhant et al 2003;Amat et al, 2012).…”

Insects and incest: Sib‐mating tolerance in natural populations of a parasitoid wasp

“…Male‐biased dispersal patterns have been reported in nonsocial insects by Downey et al () and might be explained in V. canescens by local resource competition. Males and females of V. canescens are known to be good fliers (Amat et al, ; Desouhant, Driessen, Amat, & Bernstein, ; Metzger, Fischbein, et al, ), meaning that dispersal should contribute strongly to decreasing the probability of sib encounters. Hence, if male‐biased dispersal affected the population structure in Nice and consequent encounter rates between relatives, it should be a weak effect compared to the effect of dispersal of the two sexes.…”

“…Immature development and adult life each last ~3 weeks (at 25°C), and females lay eggs during most of their adult lifespan (Metzger, Bernstein, & Desouhant, 2008), leading to overlapping generations. Field and laboratory studies have further revealed that adult females are good dispersers with a flight velocity estimated at 0.2 m/s (Amat et al, 2012;Desouhant, Driessen, Lapchin, Wielaard, & Bernstein, 2003;Schneider et al, 2002).…”

Maternal rearing condition and age affect progeny fitness in the parasitoid waspLysiphlebus fabarum

“…One important factor that was not measured in this study is the quantity of nutrient reserves that fuel somatic maintenance, locomotion, and future egg manufacture (Jervis et al., ). Nutrient reserves, such as glycogen and fat substantially affect parasitoid performance (Amat et al., ), and recent research indicates that age of the mother affects nutrient provisioning and subsequent nutrient dynamics (up to adulthood) in the offspring (Muller et al., ), but it has remained unclear how females allocate these resources to various functions. Further studies could elucidate the adaptive response of female parasitoids to environmental factors by analyzing patterns of resource allocation, as well as fitness‐related traits.…”