Friday, July 19, 2024

A Zabulon skipper in Groton on June 1. (Photo: Tom Murray)

Skippers are small, speedy butterflies that fly quickly and erratically. Most are shades of brown, orange, black or gray. You can find more than 200 species of these little guys in North America divided into two main groups: grass skippers – the largest group, with about 120 species here – and spread-wing skippers.

Because many are so similar, they can be difficult to identify, but you can spot a spread-wing skipper because it rests with its wings stretched out.

In Somerville’s Powder House Square, a Zabulon skipper rests in a jet-plane position. (Photo: Kate Estrop)

I am going to focus on grass skippers, which are are orangish with darker markings. When resting, they look like a triangle. Sometimes they rest in a jet-plane position: They spread out their hindwings and raise their forewings in a V above their backs. If you look from above and use your imagination, they look like miniature fighter jets.

Skipper caterpillars use grasses as their host plants, hence the name. Some are specialized to feed on specific grasses. These skippers tend to be rare or endangered. Most skipper caterpillars, however, feed on a variety of grasses and are widespread. Adult skippers drink flower nectar from coneflowers, asters, milkweeds and other common native plants.

Peck’s skipper

A silver-spotted skipper uses its proboscis to drink nectar from a flower in Cambridge. (Photo: Duane Mortensen)

Peck’s skippers (Polites peckius) are one of the most numerous butterflies in Massachusetts. You are likely to see them in our urban parks and yards as adults use their very long proboscis to drink nectar from among about 40 flowers, including red clover, joe-pye weed, purple coneflowers, ironweed and blazing star. They visit open areas with plenty of nectar sources, such as meadows, fields, power line right-of-ways, marshes and vacant lots.

The adults hatch and take flight in late May and June and again in August. There is some evidence that these butterflies emerge in the spring earlier today than they did in the 1800s. They usually have two broods in the North and three broods in the South; there are indications that third broods may be occurring in the Northeast in September and October.

A Peck’s skipper in Carlisle at rest displays its clubbed antennae. (Photo: Robert Gessing)

The caterpillars munch on Kentucky bluegrass, a common grass used in lawns, athletic fields and golf courses. Since there is so much Kentucky bluegrass around, these butterflies are abundant. Kentucky bluegrass is perhaps native, but farmers also brought it from Europe to plant in pastures in the 1700s. Peck’s caterpillars also feed on rice cutgrass, a sharp-edged wetland grass found in swamps and near beaver ponds. Another favored grass is native little bluestem, an ornamental grass used in landscaping. Peck’s skippers greatly benefited when European colonists cleared the forests from the 1600s through the 1800s.

The caterpillar and cocoon stages of this butterfly overwinter. If needed, they have the amazing ability to slow down their growth to overwinter as caterpillars.

The larva (caterpillar) of a silver-spotted skipper in a leaf shelter in Harvard. (Photo: Tom Murray)

According to entomologist Samuel H. Scudder (1837–1911), Peck’s skippers are “found everywhere in the open country, especially in meadows, by roadsides, along pathways and in all old forest openings; it is very fond of flowers.” These butterflies are named after the first professor of natural history at Harvard University, William Dandridge Peck.

These tiny butterflies are food for many, many other species. Some wasps lay eggs inside a caterpillar’s body. When the eggs hatch, the larvae drink the caterpillar’s body fluids and eat its internal organs, killing the butterfly. Some flies glue their eggs onto the undersides of the caterpillars. When the eggs hatch, the fly larvae burrow into the caterpillars, killing them. Still other flies lay eggs on grasses that the caterpillars eat. The caterpillars eat the eggs when they ingest the grass. Beside wasps and flies, beetles, spiders, ants and dragonflies eat the caterpillars and the butterflies. Lizards, frogs, birds and mice think these butterflies make tasty meals, too.

Zabulon skipper

A female Zabulon skipper drinks nectar on June 12, 2022. (Photo: Tom Murray)

Another species of skipper you might encounter is the Zabulon skipper (Poanes zabulon). These little butterflies are woodland butterflies, found near forested areas. The males perch on branches to defend their territories from others. Females stay in shady areas where they are more camouflaged.

Like Peck’s skippers, the females lay eggs on host grasses such as orchard grass, little bluestem and Kentucky bluegrass. The caterpillars spend their days rolled in a leaf shelter and come out to feed at night. They, too, can suspend their growth if winter is approaching. They overwinter in tightly silked rolled leaf shelters. They complete their development in the spring.

A Zabulon skipper in Groton on Aug. 29. (Photo: Tom Murray)

Zabulon skippers used to be southern butterflies. Observers in Massachusetts first saw a Zabulon skipper in 1988, near the Connecticut border. Today, the butterflies have expanded into Eastern Massachusetts. They like damp grassy fields near woodlands. You might spot them in parks, gardens and shaded weedy lawns. People first spotted a Zabulon skipper in Eastern Massachusetts in 2008. These butterflies have greatly expanded their range since.

There are many other species of grass skippers. They are all have a few things in common: They are small, they have an erratic flight pattern, they are not brightly colored and their antennae have a clubbed tip that may bend into a hook. The males of many species have scales on their forewings that produce pheromones that attract females. A species’ short, rounded wings are designed for quick, darting flights (unlike the large wings of migrating Monarchs that may travel thousands of miles) – giving it a lifestyle and a name.

A Peck’s skipper uses its long proboscis to drink nectar from a flower. (Photo: Tom Murray)

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Jeanine Farley is an educational writer who has lived in the Boston area for more than 30 years. She enjoys taking photos of our urban wild things.