I collected larvae and pupae four times (19 Jun., 23 Jul., 30 Jul., 6 Aug.) in 2004 and 2005, and three times (19 Jun., 16 Jul., 23 Jul.) in 2006 from both sensitive and marsh fern and reared them to eclosion.
The single significant interaction obtained in this study occurred between fern species and year ([F.sub.2] = 4.55, P = 0.012), an apparent consequence of eclosion occurring relatively earlier on sensitive fern than on marsh fern during the 2006 year (vs.
Wasps from 2006 were lighter than the others ([F.sub.2,158] = 7.83, P = 0.001), females were significantly heavier than males ([F.sub.1,159] = 38.83, P < 0.001) and individuals from sensitive fern were significantly heavier than those from marsh fern ([F.sub.1,159] = 4.82, P = 0.030).
The relatively rapid development of the female moths on marsh fern might form the basis for their slightly smaller size; comparable trade-offs between time and size occur in many Lepidoptera (Moreau et al., 2006; Karl and Fischer, 2008).
However, a few female moths from marsh fern with extremely short pupal periods probably furthered their ability to lay their eggs early in the season.