DOI: 10.5061/dryad.c509n
title: Data from: Meek mothers with powerful daughters: effects of novel host environments and small trait differences on parasitoid competition

description: Outcomes of competition may depend both on subtle differences in traits
 relevant to fitness and on how those traits are expressed in the context
 of the environment. Environmental effects on traits impacting population
 dynamics are often overlooked in studies of parasitic wasp (parasitoid)
 competition. Lineages of the parasitoid Diachasma alloeum (Hymenoptera:
 Braconidae) differ in relative ovipositor length (a trait affecting the
 proportion of hosts available for parasitism). Since the size of natal
 hosts affects the overall body size of many adult parasitoids, outcomes of
 competition between D. alloeum lineages should be influenced by both their
 natal host's size and their inherited ovipositor:body size ratios.
 Previous genetic work showed the unexpected result that the apparently
 inferior competitor (the lineage with smaller ovipositors in its ancestral
 environment) has successfully colonized a new host. We present body size
 measurements and a phenomological model of competition showing that
 relative ovipositor sizes of the two lineages predict success of the
 apparently inferior wasp lineage in the new host. We present several
 variants of the model, including simulations: 1) wherein competitors have
 either ancestral trait values or trait values acquired in the novel
 environment; 2) that allow varying rates of constant immigration from the
 inferior competitor's source population; and 3) with stochastic
 immigration from both lineages' source populations. We show that
 ancestral trait differences and changes in environmentally mediated traits
 interact to affect outcomes of competition. Apparently inferior female
 parasitoids (‘meek mothers’) attacking a host in a novel environment can
 produce highly successful daughters if those daughters inherit large
 ovipositor:body size ratios and grow to a larger size in the new
 environment. Predictive models of parasitoid competition that consider
 effects of environmentally mediated trait changes may be particularly
 important for biocontrol programs wherein parasitoids are introduced into
 new environments or used to control novel hosts.
description: Measurements of
 Rhagoletis pupaeLength and width
 measurements and hemispherical cylinder volume calculations of Rhagoletis
 fly pupae. These measurements represent field collected populations of
 apple-, blueberry-, and hawthorn-associated Rhagoletis fly pupae. We
 photographed the pupae and then processed all images with ImageJ to
 measure the pupae length and width. These measurements were used to
 calculate a hemispherical cylinder volume of each
 pupae.Hamerlinck_etal_Oikos_pupaemeasurements.xlsxFemale D. alloeum body character measurementsBody character measurements of apple-, blueberry-, and hawthorn-associated populations of Diachasma alloeum wasps. These wasps were reared in the lab from field collected, Rhagoletis-infested apple, blueberry and hawthorn fruits. We used a Leica IC80HD camera attached to a Leica M125 dissecting microscope to photograph the wasps and then processed all images with ImageJ to measure the wasp body size characters.Hamerlinck_etal_Oikos_femaleDalloeummeasurements.xlsx