BUTTERFLIES AND MOTHS
(Lepidoptera)
J.D. Lafontaine
CONCLUSIONS
The Mixedwood Plains Ecozone supports a diverse fauna of butterflies and moths with more than 2600 species recorded and probably another 500 species remain to be discovered. This represents almost 1/2 of the entire Lepidoptera fauna of Canada; about 1/4 of the fauna of the Ecozone are southern species that do not occur elsewhere in Canada.
Our knowledge of the Lepidoptera fauna of the Ecozone in terms of distribution, abundance, habitat requirements, and life history, varies greatly from group to group. These data are well known only for a few groups such as the butterflies and some families of large moths - e.g. Giant Silk Moths (Saturniidae) and Sphinx Moths (Sphingidae). Other groups, such as Cutworm Moths (Noctuidae), Tiger Moths (Arctiidae), Geometer Moths (Geometridae), and Prominent Moths (Notodontidae), are moderately well known, at least in terms of distribution and abundance. Most of the 45 families of Microlepidoptera are poorly known in the Ecozone. Similarly, the fauna associated with many habitats in the Ecozone are poorly known, particularly habitats associated with the Carolinian zone of southern Ontario. Many of the native habitats of southern Ontario are highly fragmented and the effects of this on the fauna are not known. It appears that the populations of Frosted Elfin and Karner Blue associated with the lupine stands at Pinery and St. Williams fell below a threshold of viability and gradually died out. The same appears to be true of Regal Fritillary on relict prairie in eastern North America where the adults range too widely for populations to remain viable on small patches of prairie. Some butterflies associated with oak savannah, such as Dusted Skipper, Mottled Duskywing (Fig. LEP-16), and Sleepy Duskywing, have been declining in recent years and may have fallen below a threshold of viability. Whether or not this is also true of Lepidoptera associated with the fragmented patches of deciduous Carolinian woodland in southern Ontario is unknown. Much more research and long term monitoring on the Lepidoptera of the Mixedwood Plains Ecozone is needed before the biodiversity of the fauna is fully documented and its long term survival ensured.
