Diario del proyecto CVC Butterfly Blitz 2022

Our seventh OOTW for the 2022 Butterfly Blitz is an observation of one of our most distinctive butterfly species – the Baltimore Checkerspot. This particular checkerspot adult was seen by Christine (@c-elliott) in the Hungry Hollow ravine in Georgetown.

Hungry Hollow has been having a mini explosion of Baltimore Checkerspots this year, with over a dozen observations made on iNaturalist. This is probably partly because Hungry Hollow is a popular walking area, and the checkerspots have been easily seen from the trails. But it’s also probably partly because of the biology of the species – when you find one Baltimore Checkerspot, you’re likely to see more.
Adult female Baltimore Checkerspots lay groups of 100 to 700 eggs together on the undersides of leaves of white turtlehead plants. After the caterpillars hatch, they hang out and feed on turtlehead leaves together in a communal nest that they construct out of silk.

After feeding for a few weeks, partly grown Baltimore checkerspot caterpillars drop to the ground and find a cozy place in the leaf litter to spend the winter. When temperatures warm up in the spring, they come out of hibernation and begin feeding again. Although young Baltimore Checkerspot caterpillars prefer to eat turtlehead leaves, the bigger ones are less picky and will feed on the leaves of different plant species – including ash trees and plantain.

Left: Communal nest of Baltimore Checkerspot caterpillars, Hungry Hollow in August 2021.
Right: Baltimore Checkerspot caterpillars feeding on ash leaves, Hungry Hollow in June 2022.

Christine shared some wonderful details on how she made this observation:

“The Baltimore Checkerspot and Acadian Hairstreak were my two target species as I headed out that afternoon, based on observations from other Butterfly Blitz participants earlier in the week (shout out to @pbuchwald, @maci_paci, @l_silva, and @bevlynn99). As uncommon species in our area, it was exciting to know that I could potentially see both within walking distance of my home. This would be my first time observing Baltimore Checkerspots in the field, making this observation both a first-of-year and lifer.

The area where I spotted both species was the newly opened extension to the Hungry Hollow Trail in Georgetown, north of West Branch Park. The boardwalk over the wet meadow made for excellent viewing opportunities with little disturbance to the surrounding habitat. To my surprise I wasn't treated to just a few butterflies of each species, but dozens.

One of my goals this year is to pay greater attention to the habitat and hosts plants for the different butterfly and moth species I encounter. While reading up about the Baltimore Checkerspot, I learned that the eggs are laid on native plants such as turtlehead and hairy beardtongue, and that adults prefer to nectar on the flowers of milkweed, viburnum and wild rose. Moving forward, I hope this information will help me to find other populations outside of Hungry Hollow in the future.”

Side note: The Baltimore Checkerspot was named after George Calvert (1580-1632), the first Lord Baltimore, whose coat-of-arms was orange and black. The Baltimore Oriole is also named after Lord Baltimore, while Baltimore, Maryland, was named by his son. It’s partly because of the name that the Baltimore Checkerspot is the official state insect of Maryland.

Did you know Ontario doesn’t have an official provincial insect? If we did, what do you think it should be?

Written by @lltimms, Senior Specialist in Natural Heritage, CVC.

Two quick updates before we get into our eighth OOTW:

1. There are still spots for this week’s guided hike at Wilcox Conservation Area. This site is in the northwest of the watershed and is a good spot to see Eyed Browns, Appalachian Browns, and maybe some of our other cool wetland butterflies – a good way to build your species list! Register here today or tomorrow morning if you’re interested.
2. Our project is up to 58 species and almost 700 observations. This is amazing work! Thank you all for your efforts!

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I often surprise people when I tell them that butterflies can be brown or other dull colours. Many assume that small or medium-sized brown flying things are moths, and don’t give them a second look. Our eighth observation of the week features one of those dull brown species - the Northern Cloudywing – hopefully we’ll convince you they’re worth paying attention to!

The Northern Cloudywing is part of a group of species called the spread-wing skippers – named because of their tendency to hold their wings out to the side when at rest. Other species in this group that we’ve written about before include the Silver-spotted Skipper, Wild Indigo Duskywing and Dreamy Duskywing. While these medium-sized butterfly species might seem superficially similar, it is easy to pick out the Northern Cloudywing when you look closely.

Northern Cloudywings are almost entirely brown, with a few translucent white spots on the forewing arranged in a somewhat random pattern. The underside of their hindwings has some faint darker brown bands. They are mostly solid brown – compared to the other spread-wing skippers that all have a larger number of white and/or orange spots and silvery colouring.

Left: Northern Cloudywing, observed by @line2 Right: Wild Indigo Duskywing, observed by @bevlynn99

Northern Cloudywings are usually seen on their own, unlike the Baltimore Checkerspots we heard about last week. Maybe this is because the males are very territorial – they will chase away anything that comes into their territory and then come back to the same perch over and over.

These butterflies are one of the many species that have benefited from the introduction and spread of non-native plant species. The native host plants of Northern Cloudywings include tick trefoils, bush clovers, and other plants in the pea family. You’re now just as likely to see their caterpillars feeding on introduced vetches and clovers.

Line (@line2) observed this Northern Cloudywing on one of her visits to Forks of the Credit Provincial Park. She says: “I have been coming fairly often to Credit Valley, looking for butterflies and moths. It's one of my favorite spots!” This may also be one of the Northern Cloudywing’s favourite spots; Line has observed one on each of her visits to the Forks.

What is your favourite butterflying spot? Let us know!

Have you ever been out butterflying and seen a flash of something orange with dark markings that was too big to be a Northern Crescent, too small to be a Monarch, and not quite the right shape to be a Comma species? If so, it may have been one of the Fritillary species found in our area.

Our ninth OOTW is one of those species – this beautiful Meadow Fritillary – observed by Marc (@marcjohnson).

There are two groups of fritillaries in Ontario: the greater fritillaries (Speyeria spp.), including the Great Spangled Fritillary; and the lesser fritillaries (Boloria spp.), including the Meadow Fritillary. Species in both groups are superficially very similar, especially when you look at the upper sides of their wings. They’re easiest to identify to species by looking at the patterns on the undersides of their wings.

Left: the underside of a Meadow Fritillary’s wings, observation by @marcjohnson
Right: the underside of a Great Spangled Fritillary’s wings, observation by @bevlynn99

Fritillaries got their name from the Latin word fritillus, which means chessboard or dice box. It is easy to see how this name applies when looking at the upper side of their wings, where the black spots on the orange background give a checkered appearance.

The ROM Butterflies of Ontario field guide refers to the Meadow Fritillary as the most common lesser fritillary in southern Ontario. But our experience after four years of the Butterfly Blitz suggests that they are not a common species in our area. The only observations on iNaturalist in the Credit River Watershed are from a single location.

Records in the Ontario Butterfly Atlas also seem to suggest that Meadow Fritillary may be less common now than it was in past decades. Other areas of North America have also noticed a range contraction for this species, while some still refer to it as common and abundant.

Is the Meadow Fritillary truly rare and declining in our area, or is it just a tricky species to find? If you’d like to answer this question, you can help by searching for this species in open, usually wet, meadows. They have multiple generations per year, so if you’ve missed them in the past few weeks, try looking again in late August.

It’s time to highlight one of my favourite groups of butterflies – the hairstreaks. Last week in the Butterfly Blitz we saw two observations of Striped Hairstreaks, by Lorysa (@lorysa) and Kevin (@kkerr). We couldn’t choose just one, so we featured both: here and here.

At first glance, it may seem difficult to tell the Striped Hairstreak apart from similar species like the Banded and Hickory Hairstreaks. When you look closer, there are key differences in wing patterns – including the width of their bands and the size and arrangement of the grey/blue and orange spots. Striped Hairstreak has very wide wing bands, and an orange ‘cap’ on the blue/grey spot in the far corner of the hind wing.

Both Lorysa and Kevin found the input of others on iNaturalist to be helpful in their hairstreak identification. Lorysa says: “I don't know enough to narrow down to specific Hairstreak it was, but comments from other members of the iNaturalist society helped me learn how to tell this was a Striped Hairstreak.” And Kevin agrees: “I'm still relatively new to butterflies but I remembered reading your comments on how to distinguish species of hairstreaks from someone else's earlier submission, so the blitz has definitely helped advance my ID skills.”

Hairstreaks in Ontario all have a little tail sticking out of the end of their hind wings. The combination of these tails, their hindwing spot patterns, and the way the butterflies rub them together, are used to fool predators into thinking there is a head on the butterfly’s wings. This trick seems to work, as it is common to see hairstreaks with a bit of their hind wing missing where a bird has taken a bite!

Striped Hairstreaks are usually seen in woodland openings and on forest edges. Like all hairstreaks, they spend a lot of time in the trees and shrubs where their caterpillars eat and only come out to nectar on favourite plants like milkweed and dogbane. Once they’ve landed to feed, it’s easy to get photos of them as they are not as skittish as other butterflies.

Both of these hairstreaks were observed while our Butterfly Blitz participants were out doing something else: Lorysa was doing a favour for a neighbour and Kevin was out for a walk with his kid. I love this kind of observation, as I’m also likely to notice butterflies at any time – my family knows that I’ve seen a butterfly if I randomly run away with my phone out. Once you start butterflying, it’s hard to stop. As Lorysa says: “Now I carry my phone at all times because you just never know when you'll see something.”