From: ASSESSMENT OF SPECIES DIVERSITY IN THE MIXEDWOOD PLAINS ECOZONE

DRAGONFLIES AND DAMSELFLIES

P. M. Catling, R. Hutchinson and B. Ménard

2. BIOGEOGRAPHY

Several species have geographic limits that correspond closely to the limits of this ecozone, including for example Enallagma antennatum, Ischnura posita (Fig. 1) and Lestes inaequalis. Various authors (Judd, 1956; Walker, 1941; Catling & Brownell 1997a) have drawn attention to the support of Soper's Carolinian boundary, approximating ecoregion 135 (the Lake Erie Lowland), by the distributional limits of damselflies. The taxa involved in this pattern include Amphiagrion saucium, Argia apicalis Argia sedula Argia tibialis, Argia translata, Hetaerina americana, Ischnura hastata, and Lestes disjunctus australis (Fig. 2), as well as some dragonflies including Perithemis tenera (Fig. 3) and Gomphus quadricolor. Several species common southward have been found in only a few locations in the southernmost portions of the ecozone. Some of these are species known to wander (eg. Tramea spp.), while others (eg. Anax longipes and Macromia taeniolata) may have local breeding populations. Walker (1958) noted that Gomphus vastus had a very interesting pattern of distribution in Ontario with two populations; one on the shores of Lake Erie, the other on the Ottawa River below Arnprior (Fig.4). A few species such as Pachydiplax longipennis extend beyond the limits of ecozone 135 into its subunits (Brownell et al. 1994) within ecozones 132, 133 and 134, but do not extend to the northern limits of the Mixedwood Plains ecoregion.

Sympetrum corruptum and Enallagma clausum are more frequently encountered to the west of Ontario, but may be well established locally. The boreal Sympetrum danae enters only the more northern parts othe ecozone and may be absent from much of ecoregions 134 and 135. Other boreal and some Appalachian species, such as Calopteryx amata (Fig.2) and Lanthus parvulus (Fig. 3) are localized within or along the edges of the St. Lawrence lowlands (ecoregion 132), the northeastern extension of the ecozone. Anax junius is evidently a migrant species that enters the ecozone but does not extend far beyond it. Another migrant, Pantala flavescens travels further to the north.