No abstract

Field studies of releases and recaptures of diurnal moths painted with yellow to resemble the edible tiger swallowtail and of black moths that resemble a toxic species of swallowtail produced these results: (i) A greater proportion of the black moths were recaptured; (ii) daily trapping for a week after each release showed that the black moths survived longer than the yellow-painted moths; (iii) an analysis of wing injuries shows that most attacks can be attributed to birds and that the yellow-painted moths were attacked more often, more vigorously, or more persistently than the black moths. These results are interpreted as showing a greater predation pressure on the yellow-painted than on the black moths and, therefore, as confirming the Batesian theory of mimicry.

Surveys in a xerophytic forests association in an Illinois sand area showed that specialized Batesian mimics of stinging bumblebees or wasps are numerous in spring and early summer, generally absent in midsummer, and present but infrequent in late summer. This extends the known occurrence of this sort of seasonal distribution among mimics to a group of mimetic species which are rare or do not occur in the mesophytic forest associations in Illinois which were surveyed by two previous investigators. Our findings support the hypothesis of these previous investigators that some temperate zone Batesian mimics may be selected to avoid the midsummer season when newly fledged, insectivorous birds are abundant and have not yet learned to shun the models which the mimics resemble.

No abstract

No abstract