Silver Spotted Skipper
Species: Silver-spotted Skipper – Epargyreus clarus
B.C. Status: Blue
These butterflies have been extirpated from the B.C coast for over 50 years, but one was spotted fluttering by a patch of giant vetch on Cortes Island – read the story here! This observation changed the silver spotted skipper’s conservation status from extirpated to endangered.
Silver-spotted skippers are small butterflies that frequent disturbed open woods, forest edges, and stream edges – essentially wherever nectar can be found. With a particular attraction to blue, purple, pink, red, and occasionally white flowers, it is no surprise that these butterflies love plants in the legume family. Although, they do not exclusively feed on legumes – they enjoy other plant nectars, insect frass (poop) and mud, assimilating nutrients from each. They can be found and even heard skipping from one flower to the next.
They are brown in colour, with orange bands on their fore-wings, and silver spots on the underside of their hind-wings. When resting on a plant, they hang upside down on the leaf with their wings up, thus exposing the silver spots. They are the easiest to spot of the skippers and the largest of the skippers found in North America.
The summer months are when they are active. They can have one to two generations per summer and then they hibernate in the winter months in leaf shelters. They typically are day-fliers and are not seen in groups. They live nearby or on host plants and this is where they lay their single egg.
Silver-spotted skipper caterpillars have a unique body shape and colour. They live in leaf shelters that they make on or near their host plant. To make their shelters they bite the leaf margin, fold it over, and silk it together; making for good protection.
They make four distinct types of leaf shelters during development and their shelter grows with them by adding more leaves. Silver-spotted skipper larvae only leave their leaf shelter at night, on cloudy days to feed, or to make a larger shelter. Caterpillars over winter in their leaf shelters and pupate there, emerging as butterflies in the late spring.
The larvae do have predators such as wasps and ants. Although the leaf shelter gives much camouflage, their scent is still distinguishable. Read the Cool Facts below to read their defence mechanisms!
Alongside predation – increasing invasive insect species – there are a few potential causes for the silver spotted skipper butterfly to have been considered extirpated, and speculation as to why they have left the coast. Decrease in food-plant/host-plant density, warmer summers, which are hard on these delicate butterflies, urban development, wild-fires, and parasitism are some potential reasons.
Identification – what to look for:
- Brown in colour
- Forewings have an orange band and are very pointed
- Hind wings are short and rounded with a silver spot on the underside
- Adults have long tongues
- Big black eyes
- Yellowish-green body
- Constricted neck
- Large brownish head, with two prominent red-orange eyespots set at the front of the head capsule.
Where are they found?
- Disturbed open forests, woodland edges
- Stream edges
- Southern Canada, most of the continental states, and Northern Mexico
- Caterpillars have two big orange spots on their head that serve to scare away predators.
- Silver spotted skipper larvae/caterpillars have an anal comb which helps them throw their excrement about 38 body lengths away from them, deterring predators from their shelters.
- When disturbed, the larvae regurgitate a pungent, green chemical to further deter predators.
- Silver-spotted skipper butterflies almost never visit yellow flowers.
- These butterflies are often referred to as ‘nectar-thieves’ as they do not pollinate after feeding on the nectar. They reach the male parts of the flowers, without touching the female parts of the flowers, thus no pollination.
- On hot sunny days they are often found hanging out on the undersides of leaves, catching a good rest in the shade.
- Males are often seeking out females, spending time near a host-plant and watching each insect flying past to find a potential mate.
YouTube: Silver-spotted skipper butterfly foraging on flowers
University of Wisconsin: Master Gardener Program – Silver-spotted skipper
Butterflies and Moths of North America: Silver-spotted Skipper
Butterflies at Home: Silver-spotted Skipper
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Friends of Cortes Island Society (FOCI) is a charitable organization that has been active for over 25 years. Our organization exists to monitor and preserve the health of local ecosystems, and to provide educational programs that foster a greater understanding of the natural environment. Through all of our projects, we work to promote environmental integrity through community responsibility.