Update: A number of imperfect copies of my guides are available at a discount price!
Here's a small sample from the newest edition of my Pocket Guide for Southern and Eastern Ontario that illustrates some of the features and how to interpret them.
Note that the butterflies are now shown against a white background for greater clarity.
The Maritimes guide has a similar layout, while my Quebec guide still uses the older layout ( visit my Butterflies of Quebec website to see a sample of that guide ).
Markings on both upper and lower wing surfaces can be helpful for identification. Note that some butterflies almost never show their upper wing surfaces. In these cases, only the ventral (lower side) view is provided.
The green text specifies one of 5 size codes:
VS - Very Small
S - Small
M - Medium
L - Large
VL - Very Large
The corresponding size ranges are provided in the guide's legend. These indicators are based on measurements of typical specimens, but please note that some species can vary considerably in size.
The red text indicates the species status. These codes are explained below:
C - Common - Relatively easy to find in suitable habitat during the flight season indicated
U - Uncommon - Somewhat harder to find, even during the peak of its flight season
R - Rare - Seldom seen, even in ideal habitat during the peak of its flight season
L - Local - the species in question is usually confined to some kind of specialized habitat (eg. bogs), or seldom strays far from its larval foodplant. You may never see it unless you visit the right habitat.
M - Migrant - the species in question does not normally overwinter in Ontario, but flies North from the U.S. Some species are regular migrants ( eg. The Monarch ), while others are only reported occasionally ( eg. White-M Hairstreak ). Even regular migrants can vary in abundance from year to year.
S - Southern - the species in question is more commonly found in the extreme South of Ontario. This designation often applies to Migrant species which do not go far beyond the northern shores of the Great Lakes, or resident species that are confined to the Carolinian Zone.
N - Northern/Eastern - the species in question is less frequently reported in Southern Ontario. This designation often applies to resident species that are near the southern limit of their range in Central and Eastern Ontario, and may only occur in small localized pockets in extreme Southern Ontario.
Note that these status codes are intended as rough guides. Certain rare species can appear to be relatively common during a good year if you happen to find yourself in just the right habitat during the peak of their flight season. On the other hand, species that are normally common might be tough to locate during a bad year.
Please note that some species have several common names, and Scientific names can change as taxonomists revise species classifications. The names used in the guide have been chosen to align with the resources most commonly used by Ontario Lepidopterists ( see references ).
For some species, there is little difference in the appearance between males and females. In other species, sexual dimorphism can be significant. Where there is a noticeable difference, images of both sexes are provided ( as indicated by the symbols ♂ for male and ♀ for female ).
In addition, there are a few species that have seasonal forms or regional variants. Separate images are provided where appropriate.
These charts give a rough indication of the time of year during which you can expect to find each species. Green indicates the period during which they have been most frequently reported ( according to the Ontario Butterfly Atlas ). Yellow indicates the period during which there have been fewer reports. Note that some species have very brief flight periods, which can last only a week or two. The timing of this peak flight period can vary from year to year ( depending on weather conditions ), and from place to place ( typically earlier in more Southerly locations ). The result is that when combining reports of sightings over many years and across the province, the peak flight period of such a species may appear much longer than it will ever be in any particular place and in any particular season.