Rearing populations from three different MOTU (2, 4, and 5) for one or two generations in the laboratory revealed the sensitivity of the developing shell shape to the experienced environmental conditions.
This process is called a genetic drift and can lead to a substantial reduction in the genetic variability within the reared population.
Eggs of Manduca sexta (Ms) and Heliothis virescens (Hv) from in-house reared populations were kept in a growth chamber (Snijders Scientific, http://www.snijders-tilburg.nl) at 26°C 16 h light, 24°C 8 h darkness, until the larvae hatched.
Females recently emerged from their chrysalis were placed in the cage with several males taken from larger rearing populations.
In order to limit the loss of genetic diversity as a consequence of genetic drift, all rearing populations (i.e., from which experimental parasitoid individuals were obtained) comprised a high number of parasitoid individuals collected in the field (>300 individuals).
Larvae were reared in population cages and fed on young maize (Zea mays) plants ad libitum (except for experiment 8; see below).
We reared one population each from invasive (Fig. 1a, St . Lawrenceat Montmagny) and noninvasive clades (Fig. 1b, St . Lawrenceat St .Jean Port Joli) across three food concentrations (700, 2800, 14 000 algal cells/mL, using Rhodomonas minuta) in fresh water (0 PSU, Lake Michigan water) and measured survival and development time.
Genomic DNA was extracted from a pooled sample of ∼15,000 individuals of G. salaris obtained from an experimentally reared parasite population on Atlantic Salmon (Salte et al. 2010) using the E.Z.N.A. Tissue DNA kit (Omega Bio-Tek) following the Tissue DNA-Spin Protocol.
The anogenital and ventral abdomen regions of males from the rearing substrates study were also compared for a more extensive set of CHCs and putative triacylglycerides not found elsewhere on the flies (see below) in order to determine whether amounts of these compounds were influenced by rearing substrates and population differences.
Determining the impact of different captive rearing approaches on population productivity in species of conservation interest is central to measuring their success, but empirical studies on such species are usually constrained by the natural systems in which they operate.
