What makes this odd is that after mating, females go on long flights over the prairie without laying, apparently judging the general quality of the prairie in which they are about to lay, but when they search at a smaller scale, they seem to lay on any dead plant they happen across. The fact that P. idalia seems to lay rather haphazardly was suspected by some lepidopterists, given the fact that Regal Fritillaries produce a relatively large number of eggs. This fact alone suggests that they leave a lot of eggs in a quite unpredictable environment, subjecting them to a sort of sweepstakes of survival. This makes some sense, since what is important to young caterpillars is not where the violets are this year, but where they will germinate next Spring. That fact is apparently impossible to predict from the dry grasses of the prairie, so mother fritillaries just try to pick a generally good habitat, and then lay in a place where the egg can survive.
Mother knows best, but sometimes mother has to leave something to just chance.
Refer to the Invertebrate Zoology Glossary , in pdf or html format. Larval barnacles look for a place to settle, whereupon they develop their protective covering and filter the water with their feathery legs. To test these alternate hypotheses, Jeffery cleared patch of barnacles in different coastal locales, in two different years, and she measured the resulting rate of resettlement by new C. tasmanica . She predicted that if only amount of free space available for settlement was important, then the number of settlers per unit area of free space would be the same for each of the three sizes of cleared patch. Alternatively, if exposure to adults around the perimeter was important, then, Jeffery predicted, the number of new barnacles settling per unit length of perimeter would be the same for the three different-sized patches.