patch's carrying capacity (Dethier and MacArthur 1964). As the butterflies deplete the host and

nectar plant resources in the habitat, a "migratory threshold" would be reached (Baker 1984).

This threshold is a theoretical limit to the rate of migration so that as the threshold is exceeded,

dispersal away from the patch would begin to surpass dispersal into the patch, continuing this

way until returning to a stable density. This stable density would be below the carrying capacity

and allow key resources of the habitat such as nectar and host plants to regenerate, allowing for

more immigration in the future.

Dispersal and the Farms

 The notion of conspecific density is of particular importance to this study of butterfly

farms, which have artificially high conspecific densities. It is clear that farm enclosures are

artificially stocked with butterflies, yielding this artificially high conspecific density. However,

it has not been documented whether or not butterflies occur in high numbers around the exterior

of the farm epicenter.

 The enclosures at butterfly farms present a special circumstance when considering habitat

patches and conspecific densities. They may be treated as separate habitats due to the walls

excluding immigration and migration. At the same time, however, they may still serve as an

attractive force (i.e., presence of host plants, nectar sources, pheromones and visual signals

emanating from potential mates, etc.) to wild populations of butterflies, in which case they could

be considered part of a larger patch that includes all areas of the butterfly farming operation.

According to Hanski et al. (1994) and Kuussaari et al. (1998), butterflies may be attracted to

high conspecific densities in search of an appropriate mate. Additionally, Gilbert and Singer

(1973) suggested that high conspecific densities may also attract butterflies when acting as a cue

for good habitat quality. Should these theories apply to butterfly farms as well, a great problem