Baltimore Checkerspot Butterflies in Ontario, Canada

baltimore checkerspot butterfly, rouge national urban park, markham, ontario

Back in June of 2017, Bob and I became aware of some Baltimore Checkerspot Butterflies that had been observed in Toronto.  We were really struck by the beauty of these butterflies, a species that we had never seen before.

baltimore checkerspot butterfly, glendon forest trail, toronto, ontario

Photos of the Baltimore Checkerspot Butterflies had appeared on Facebook, on a page dedicated to Ontario Butterflies, Dragonflies and Moths.

baltimore checkerspot butterfly, rouge national urban park, markham, ontario

We reached out to the person who posted photos and were pleased to hear back from her promptly with directions as to the butterflies’ precise location.

glendon forest trail, toronto, ontario

The next day, June 26, Bob and I drove across the city to the Glendon Forest Trail.

baltimore checkerspot butterfly, glendon forest trail, toronto, ontario

We had been instructed to walk to an area designated as a wetland, and sure enough, we found some Baltimore Checkerspot Butterflies basking in the sun on the sandy trail.

baltimore checkerspot butterfly, glendon forest trail, toronto, ontario

Baltimore Checkerspot Butterflies can most often be found in wet meadows or marshes with a water source and few trees and shrubs.

baltimore checkerspot butterfly, glendon forest trail, toronto, ontario

Baltimore Checkerspot Butterflies are named for the first Lord Baltimore, George Calvert, because the colours of the butterfly are the same as those on his family’s heraldic crest.

baltimore checkerspot butterfly, glendon forest trail, toronto, ontario

The largest city in the U.S. state of Maryland is Baltimore, and so the state chose the Baltimore Checkerspot Butterfly to be its official state insect.

jean photographing a baltimore checkerspot butterfly, glendon forest trail, toronto, ontario

The flight of a Baltimore Checkerspot Butterfly is relatively weak, so they can often be found on the ground or perching on vegetation.

jean in rouge national urban park, toronto, ontario

Jump forward 3 years, and on June 14, 2020, Bob and I were hiking in   Rouge National Urban Park   in Toronto.  The area was riparian habitat near Little Rouge Creek.

baltimore checkerspot larva, rouge national urban park, toronto, ontario

As luck would have it, when passing through an area of almost waist-high vegetation, I looked down and spotted a caterpillar.

a baltimore checkerspot larva, rouge national urban park, toronto, ontario

Using an App on my cellphone, I was able to determine that it was the larva of a Baltimore Checkerspot Butterfly.

baltimore checkerspot larva, rouge national urban park, toronto, ontario

What Bob and I were observing was a fourth in-star caterpillar that had recently emerged from hibernation, probably around the end of May.

jean in rouge national urban park, toronto, ontario

Early the previous autumn, it and other fourth in-star Baltimore Checkerspot larvae fell from their host plants, hibernated in rolled leaves on the ground for the winter, and waited until the weather warmed up the following spring.

baltimore checkerspot larva, rouge national urban park, toronto, ontario

This Baltimore Checkerspot Butterfly larva hatched from an egg as a first in-star caterpillar a year earlier, sometime around mid to late June.

bob in rouge national urban park, toronto, ontario

Now feeding on a variety of host plants, this fourth in-star larva was almost fully grown and would soon spin a chrysalis.  Within the chrysalis, the larva would pupate over the course of a 2-week period and emerge as an adult Baltimore Checkerspot Butterfly.

bob in rouge national urban park, markham, ontario

During the coronavirus pandemic, Bob and I often resorted to walking deserted country roads and lanes rather than busy hiking trails.  Two weeks after finding the Baltimore Checkerspot larva, on June 30, 2020, we were fortunate once again to come across some Baltimore Checkerspot Butterflies, this time near our own home.

baltimore checkerspot butterfly, rouge national urban park, markham, ontario

These butterflies were members of a new generation of Baltimore Checkerspot Butterflies that had recently emerged from their chrysalides.  Baltimore Checkerspot Butterflies produce one generation a year.  Their flight time in Ontario is from mid-June to early August.

baltimore checkerspot butterfly, rouge national urban park, markham, ontario

Newly pupated Baltimore Checkerspot Butterflies actively seek mates so that they can propagate.

baltimore checkerspot butterfly, rouge national urban park, markham, ontario

During this period, male Baltimore Checkerspot Butterflies perch near the ground as they search for a female.

baltimore checkerspot butterfly, rouge national urban park, markham, ontario

The females then lay between 100-700 eggs in groups on the appropriate host plant.  White Turtlehead is the plant preferred by the tiny first in-star caterpillars once they hatch.

baltimore checkerspot butterfly larva, rouge national urban park, toronto, ontario

Starting life as a first in-star larva, a Baltimore Checkerspot caterpillar will join other first in-star larvae to spin a communal web on a White Turtlehead plant.  This protects the larvae from predators as they eat, grow and molt from first in-star to third in-star caterpillars.

baltimore checkerspot butterfly, glendon forest trail, toronto, ontario

Late in the summer, the larvae stop eating and remain in the pre-hibernation web until the weather grows cooler.  Then, the caterpillars drop to the leaf litter where they hibernate for the winter months.

baltimore checkerspot butterfly, rouge national urban park, markham, ontario

Baltimore Checkerspot Butterflies look like they only have 4 legs rather than 6.

baltimore checkerspot butterfly, rouge national urban park, markham, ontario

This illusion is created because the two front legs are reduced in size.  This is why these butterflies are classified as brush-footed butterflies.

bob in rouge national urban park, markham, ontario

So, while Bob and I observed the Baltimore Checkerspot Butterflies and larva in 3 different locations at 3 separate times, we were actually given a glimpse into the life cycle of these most beautiful creatures.

baltimore checkerspot butterfly, glendon forest trail, toronto, ontario

Now, if only we could find a chrysalis!

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Frame To Frame – Bob and Jean

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