Host Suitability of a Gregarious Parasitoid on Beetle Hosts: Flexibility between Fitness of Adult and Offspring

Abstract

Behavioral tactics play a crucial role in the evolution of species and are likely to be found in host-parasitoid interactions where host quality may differ between host developmental stages. We investigated foraging decisions, parasitism and related fitness in a gregarious ectoparasitoid, Sclerodermus harmandi in relation to two distinct host developmental stages: larvae and pupae. Two colonies of parasitoids were reared on larvae of Monochamus alternatus and Saperda populnea (Cerambycidae: Lamiinae). Paired-choice and non-choice experiments were used to evaluate the preference and performance of S. harmandi on larvae and pupae of the two species. Foraging decisions and offspring fitness-related consequences of S. harmandi led to the selection of the most profitable host stage for parasitoid development. Adult females from the two colonies oviposited more quickly on pupae as compared to larvae of M. alternatus. Subsequently, their offspring development time was faster and they gained higher body weight on the pupal hosts. This study demonstrates optimal foraging of intraspecific détente that can occur during host-parasitoid interactions, of which the quality of the parasitism (highest fitness benefit and profitability) is related to the host developmental stage utilized. We conclude that S. harmandi is able to perfectly discriminate among host species or stages in a manner that maximizes its offspring fitness. The results indicated that foraging potential of adults may not be driven by its maternal effects, also induced flexibly with encountering prior host quality.

Survival to Parasitoids in an Insect Hosting Defensive Symbionts: A Multivariate Approach to Polymorphic Traits Affecting Host Use by Its Natural Enemy

“…Several studies have previously considered host variation affecting specificity, or lack thereof, of Aphidius parasitoids at the inter-specific ([28] and references therein; [12], [50]) and intra-specific levels [9], [51], [52]. The objective here was to study specialization at the intraspecific level (polymorphism), which we did with ten phenotypically well-characterized clones of the host A. pisum, and two lineages of the A. ervi wasp in a transplant experiment.…”

Sex ratios, virginity, and local resource enhancement in a quasisocial parasitoid

“…Some Sclerodermus species exhibit extremely female‐biased sex ratios (Griffiths & Godfray, ; Hardy & Mayhew, ; Li & Sun, ; Hu et al., ; Tang et al., ). Although most offspring groups consist mainly of females, some consist entirely of females (‘virgin broods’).…”

Factors Affecting the Reproduction and Mass-Rearing of Sclerodermus brevicornis (Hymenoptera: Bethylidae), a Natural Enemy of Exotic Flat-Faced Longhorn Beetles (Coleoptera: Cerambycidae: Lamiinae)

“…Stimulated by successes in agro-forestry systems in China [ 47 ], there is growing interest in the use of parasitoids in the bethylid genus Sclerodermus Latreille. These are idiobiont ectoparasitoids [ 48 , 49 ], typically attacking coleopteran larvae, mainly wood-boring beetle larvae (Cerambycidae, Scolytidae, Anobiidae and Bostrichidae) [ 50 , 51 ]. Their flattened body and their strong mandibles allow them to enter narrow places in search of hosts, excavating in the frass of pre-existing galleries bored in the wood by the xylophagous beetles [ 50 , 52 , 53 , 54 , 55 ].…”