Porch Light Naturalist

Most people have seen a light during a warm, summer night with numerous moths flying around it. The reason for this is often thought to be related to the idea that moths use the moon as a point of reference while flying around or migrating. To moths and other insects, a bright artificial light may look like the moon, so they use that as a guideline rather than the real moon. As a result, the moths get disoriented and flutter around the light.

This disorientation and movement towards the light (not technically "attraction") allows close observation of many insects species that would be difficult to find otherwise. For the past week or so, I have been going out to the porch light after dark and checking to see what shows up. Over the course of about one week, I have recorded about 60 species of moths near the light, as well as numerous species of other insects including mayflies, wasps, beetles, and stink bugs.

A common moth species this time of year is the Pink-barred Pseudeustrotia (Pseudeustrotia carneola). This species is easily recognized by the two light-colored bands that break up the dark areas of the wing.

Unlike the previous species, the Common Idia (Idia aemula) is a fairly plain species. This is a very light-colored individual.

Moths come in many shapes, sizes, and colors. This Grape Leaf-folder Moth (Desmia sp.) is a relatively small moth, with a wingspan of about 2 cm and a distinctive shape and pattern.

This yellow moth, Sparganothis xanthoides, is one of many species of moths that I had never encountered before.

As the name would suggest, the large Tulip-tree Beauty (Epimecis hortaria) is a gorgeous moth.

Another aptly named moth is the Beautiful Wood-Nymph (Eudryas grata). The beautiful patterns and colors on this moth made it stand out from many of the brown and gray species at the light.

This Leuconycta diphteroides is rather dull, but if you look carefully, the wings have very interesting patterns.

Although this moth appears very different from the previous picture, this is another

Leuconycta diphteroides. This one is much brighter and more colorful, so the patterns really stand out.

Most of the previously mentioned moths are relatively large and easy to see as they sit on the edge of the house. However, some moths require a bit of searching because their small size makes them difficult to find. One example of such a moth is this Diamondback Moth (Plutella xylostella), which has a wingspan of about one centimeter. Although hard to imagine, this species is a well-documented transoceanic migrant!

The Speckled Xylesthia Moth (Xylesthia pruniramiella) is another small moth that blended in with the wall on which it was perched. This species has distinct "ridges" on the top of its wings.

The Double-banded Grass-Veneer (Crambus agitatellus) is the most common small moth at the porch light this time of year. This species is also commonly found in the woods and meadows near the house.

Plenty of non-moth insects come to the light as well. This stinkbug, Banasa calva, is a species that I have only ever seen around lights at night.

While many of the moths come to the light for the reason mentioned at the beginning of this post, this Dimorphic Jumping Spider (Maevia inclemens) came to the light to find an easy snack.

This Ichneumon wasp in the genus Netelia is only one of several wasps that I see at the porch light each evening.

Mayflies, like this one, are frequently found at the porch light. A few weeks ago, during the BioBlitz at Jacobsburg State Park, lots of mayflies were found on the illuminated walls of the park office.

A Trip to Ricketts Glen State Park

This Saturday, my mom, brother, and I traveled to the area around Ricketts Glen State Park. Our first stop was State Game Lands #57, which is located directly north of the state park. Upon arriving, we parked in a gravel lot situated next to this rocky stream. The stream was bordered with plants such as meadowsweet and silky dogwood.

The muddy parking lot was a perfect location for "puddling". Puddling is a behavior exhibited by many butterflies in order to collect minerals. Certain butterflies, like this Red-spotted Purple, are commonly found at puddles and muddy areas.

We found this White Admiral in the same parking lot. This White Admiral actually belongs to the same species as the previous butterfly. The two subspecies are different in appearance, but are almost identical in structure. The White Admiral is the more northern subspecies of the species.

From the parking lot, we walked along a grassy road that meanders along the creek. This partially wooded area was filled with dragonflies including this female American Emerald.

Chalk-fronted Corporals were another extremely common dragonfly along this road. Over the course of a few hours, we saw over one hundred of these skittish insects.

After a little while, the road became muddy, and we found ourselves in a sphagnum bog. The waterlogged Sphagnum moss provides an excellent place for certain unusual plants to grow. My mom spotted this round-leaved sundew, a carnivorous plant, growing along the edge of the trail. Sundew plants trap prey in the sticky "dew" on the leaves. The plant then secretes enzymes that dissolve the insect and allow the plant to receive essential nutrients.

The bog, which is very similar to habitats found farther north, is home to "northern" butterflies like this Common Ringlet.

Leatherleaf is another plant that is common in the bog on State Game Lands #57.

One of the most well-known bog plants is the cranberry. At the time we explored the bog, the flowers were just beginning to open.

The bog is filled with various grasses, sedges, and shrubs that grow on top of a thick layer of Sphagnum moss.

In the game lands between the bog and the road, we walked along a section of forest that was recently logged. The logging created perfect habitat for many bird species. While hiking through this area, we heard several Least Flycatchers, Yellow-rumped Warblers, and White-throated Sparrows.

The logged area also opened up habitat for unusual dragonfly species. I photographed this Maine Snaketail after it caught a small insect, and then perched to eat.

After exploring the game lands, we headed into the state park. Our first stop was at "the Hayfields," a large expanse of grasses and highbush blueberries. From the top of the hill, we saw a large swath of purple flowers in the wetland below.

As we walked down to the wet area, we realized that the purple flowers were blue flag irises.

From the Hayfields we travelled to the main attraction of Ricketts Glen, the waterfalls. Along the wooded trail, we found numerous lichen-covered trees and moss-covered rocks.

The damp, rocky forest provided perfect habitat for plants such as this hobblebush.

The woods at Ricketts Glen are a wonderful place for wildflowers. We found several spring flowers that were going to seed. Trilliums were some of the more common wildflowers along with starflower, indian cucumber-root, and northern wood-sorrel.

After walking for a while, we finally reached the first waterfall. The sight of the falling water, green hobblebush, and textured bark of the hemlocks was a splendid sight!

The Falls Trail at Ricketts Glen travels down along one creek then climbs up along another providing great views of over twenty waterfalls.

While hiking along the stream, we found this mountain maple growing along the stream. Unlike many other species in the genus, mountain maple has flowers that grown on a cluster.

The most abundant wildflower along the waterfalls was northern wood-sorrel, which has flowers ranging from white to pink.

We had a great day of hiking and exploring!

Brake for Turtles!

In late May and throughout June, several turtle species complete a short migration in order to reach breeding grounds. Two of the most commonly encountered turtles during this movement are the Eastern Box Turtle (Terrapene carolina) and the Wood Turtle (Glyptemys insculpta). These turtles may cover large distances as they move from the woodlands and meadows (where they live for most of the year) to wetlands for breeding. Once these turtles mate and the females have laid eggs, the adults turn around and return into the woods from which they came.

Eastern Box Turtle

Wood Turtle

In order to reach suitable breeding habitat, the turtles must cross large expanses of land. In today's world, this means that the turtles are forced to cross roads. Roads situated in turtle habitat are often small, back roads with relatively little traffic, which could be good for the turtles. However, people often travel at high speeds along these curvy roads, and a slow, road-crossing turtle stands no chance against a two ton car. As a result, many turtles are killed this time of year. While traveling along a wooded road during the morning hours and after a evening or nighttime rain, it is not uncommon to find several dead box and wood turtles.

Wood Turtle crossing a road

Spotted Turtles (Clemmys guttata) are occasionally found walking across roads.

During the breeding season, it is incredibly important to look out for these turtles as they are crossing roads. These turtles, especially the Eastern Box Turtles, are known to be rapidly declining throughout much of their ranges. The last thing this species needs to face is death by automobiles. This problem can be greatly reduced by people who drive through these turtle crossings. Simply moving the turtles to the side of the road can save the life of the turtle and possibly the offspring.

One word of caution: while Eastern Box and Wood Turtles are easy to carry across a road, don't attempt to help a Snapping Turtle unless you have no need for your fingers!

Snapping Turtles are also commonly seen crossing roads, but don't attempt to pick up one of these!

Appalachian Azure

Within the last twenty years, researchers have made several discoveries involving the butterfly genus Celastrina, the azures. Several years ago, there was only one recognized species in the eastern United States, the Spring Azure (Celastrina ladon). Now that scientists can look at DNA sequences, it has become clear that there are several distinct species in this region. As I have mentioned in previous posts, there are five species that are commonly found in eastern Pennsylvania. The Northern Spring (Lucia) Azure (Celastrina lucia) is the first azure to appear in spring. This species is most common in the mountains from the Kittatinny Ridge and north from there. The Northern Spring Azure primarily eats the leaves and stems of blueberries (Vaccinium) as caterpillar.

Northern Spring Azure, Celastrina lucia

The second species to emerge in spring, often in the first week of May, is the Spring Azure (Celastrina ladon). Almost identical to the previous species, the Spring Azure is the common azure for the first few weeks of May. In the Lehigh Valley, which is located south of the Kittatinny Ridge, this seems to be the predominant azure species. The Spring Azure's primary caterpillar food plant is flowering dogwood (Cornus florida), a common tree of deciduous forests.

Spring Azure, Celastrina ladon

Beginning around the third week of May, a new batch of azures can be found in the woods and forest edges. At this point, many Spring Azures are worn and dull, as they have been flying for a few weeks, so they can be separated from these new Cherry Gall Azures (Celastrina serotina). This species uses Wild Black Cherry (Prunus serotina).

The longest-lasting of the azures is the Summer Azure (Celastrina neglecta). This species is the most distinct of any of the species already mentioned. The spring species are usually well-marked with dark spots, but Summer Azures are often very very pale and chalky white rather than blueish gray. As a caterpillar, the Summer Azure may use several shrub species including silky dogwood (Cornus amomum) and meadowsweet (Spiraea latifolia). Since these plants are commonly found along woodland edges and brushy fields, this butterfly is often found in these habitats rather than woodlands.

Summer Azure, Celastrina neglecta

The fifth and rarest species is the Appalachian Azure (Celastrina neglectamajor). This large, pale azure flies at the same time as the Summer Azure, but only feeds on black cohosh (Actaea racemosa; syn. Cimicifuga racemosa). The female Appalachian Azure lays her eggs on the unopened flower spikes of this cohosh. Once the caterpillar hatches, it feeds on the flower buds and stems (Pavulaan & Wright, 2000).

Appalachian Azure (Celastrina neglectamajor) on the host plant

In Pennsylvania, this species is primarily found in the southern half of the state. A few years ago, I learned that this species had never been found in my home county. After learning this, and after finding a large patch of the host plant, I kept an eye out for any azures in that area. In 2009 and 2010, I checked the plants for eggs and caterpillars, but was unsuccessful. This year was different. While I was in the woods, I spotted an azure flying just above my head. I followed the azure in an attempt to get a better look. I followed the blue speck until it led me to the patch of black cohosh and finally landed--on the host plant for the Appalachian Azure. Until this point, I had assumed that this was another one of the ubiquitous Summer Azures. I immediately checked the flower spike of the closest cohosh plant. Sure enough, I found two azure eggs situated between the flower buds! This was the first sighting and documented record of Appalachian Azure in Monroe County (confirmed by David M. Wright), which could be a sign of range expansion since these butterflies were not observed at this location in previous years. In the next week or so, I hope to return to the patch of cohosh and count the number of eggs present and hopefully get photos of adults and caterpillars.

Appalachian Azure eggs on buds of Actaea racemosa

Pavulaan, Harry and David M. Wright. "The Biology, Life History, History, and Taxonomy of Celastrina neglectamajor (Lycaenidae: Polyommatinae)." The Taxonomic Report. 2.5 (2000): 1-19. pdf.

Some Cool Ferns

During the warmer months of the year, ferns are common plants of the forest floor. Some of the most common ferns in this area are hay-scented fern (Dennstaedtia punctilobula), the wood ferns (Dryopteris), and bracken fern (Pteridium aquilinum), however, there is a large variety of less common and fascinating fern species that inhabit our woods and meadows.

Sensitive fern (Onoclea sensibilis) is a easily recognizable fern of damp or wet areas. This species often grows in wet, wooded areas or along forest edges. Many areas where this fern grows many not appear wet at first, but a closer examination under the soil will show that the area is indeed wet enough to support a group of these ferns. Many ferns are characterized by their divided leaves and branching vein system. Sensitive ferns are different in these respects, as the fronds only have several large divisions and contain a "netted" vein system.


Climbing fern, also known as Hartford fern (Lygodium palmatum), is a truly exciting species to find. If a casual observer passed this plant in a wet meadow, they would not realize that it is a fern. The palmate leaves and vine-like growth make this plant unlike any other fern in the region. Much like the sensitive fern, climbing fern needs a certain amount of moisture in the soil in order to survive. However, climbing fern is no where near as frequently encountered as sensitive fern. This species is listed as rare in Pennsylvania, as it is found in relatively few locations around the state. Despite being considered relatively rare, where climbing fern does occur, it often grows in large patches covering acres of ground. Climbing fern also has an interesting history, as it was the first plant in the United States to have a protection law. These vine-like plants were once collected for decorations, causing the populations to significantly decrease, which resulted in a Connecticut law banning the collection of this species.

Although it may look like many other ferns, rattlesnake fern (Botrychium virginianum) is very different than other common forest ferns. The major distinctive feature is the fertile frond that is different than the rest of the plant. In the photo, notice the "snake rattle" that grows like a frond off the main stem (where the plant gets its name); this is the fertile frond. Many other fern species produce spores on the undersides of normal, leafy fronds, but this is not the case with rattlesnake fern. This unique fertile frond is where the spores are produced. This distinctive feature allows for easy identification of this fern. Rattlesnake ferns are common along woodland edges and in small openings in the forest.


Triangle grapefern, or triangle moonwort, (Botrychium lanceolatum) appears to be an opposite of the rattlesnake fern. Rattlesnake ferns have a large sterile frond and a relatively small fertile frond, but this grapefern has a huge fertile frond and a thin, small sterile frond. This species is much less common than rattlesnake fern and is only occasionally found in wet or damp woods.

These are just a few of the many interesting ferns that grow in the woods this time of year. The next time you are in the woods, keep an eye out for these species that are often overlooked due to the presence of more colorful and showy plants and flowers.

Late Spring Butterflies

Summer is known as the best time of year for butterfly diversity. With warm temperatures and blooming flowers (e.g. joe-pye-weed, beebalm, and milkweeds), butterflies can be extremely abundant. During this time, the species diversity of butterflies is very high; in mid-July, it is not uncommon to easily find 20-30 butterfly species in a single meadow. As a result of this high diversity and abundance of brightly-colored species, many "butterfliers" wait until this prime time to go looking for these insects.

Although summer is often considered the best season for butterflies, many unique species show up around late spring. Many of these species only fly for a short time period, so by the time the summer butterflies emerge, these interesting spring species are no longer around. Unlike summer, where large, flower-filled meadows and gardens seem to be hotspots, spring butterflies prefer woodlands and grassy meadows or shrubby areas.

A meadow with warm-season grasses, greenbrier (Smilax), and meadowsweet (Spiraea) is perfect for spring butterfles.

The only downside to finding butterflies during the spring is that they rarely sit still. Since there are few flowers blooming for the butterflies to get nectar, the butterflies do not sit still for very long. However, if flowers such as northern dewberry (Rubus flagellaris) are blooming, the butterflies may congregate around the flowers.

Here are some interesting late spring butterfly species that are currently are flying or will be emerging very soon. If you see these species, please report them to the Eastern Pennsylvania Phenology Project.

Many of the common spring butterflies are classified as "skippers" a group of small, plain butterflies that are commonly found in grassy areas. The butterfly pictured above is a duskywing, which is a type of skipper. This species is most likely a Wild Indigo Duskywing, a common species of open areas. However, there is the possibility that this is a Columbine Duskywing, a little-known species that is virtually identical to the Wild Indigo. Due to the fact that these species are so similar, it is possible that the Columbine Duskywing, although considered rare now, may be more common than researchers currently know. These Wild Indigo-type Duskywings are just beginning to emerge in northeastern Pennsylvania.

This butterfly, a Dreamy Duskywing, is a common butterfly of late spring and early summer. As a caterpillar, Dreamy Duskywings eat the leaves of birches, aspens, and willows, so the adults are commonly found in open meadows or fields near forests where these trees grow. Unlike Wild Indigo Duskywings, a fairly large skipper, Dreamy Duskywings are very small and often avoid detection due to this size as well as their quick flight. This species is very similar to the Sleepy Duskywing, a species that flies a few weeks earlier and is mostly gone by the time Dreamy Duskywings emerge.

Another "large" skipper is the Northern Cloudywing. The cloudywing is similar to the duskywings, but has a different wing shape, often sits with its wings partway open (whereas duskywings often sit with wings fully opened), and does not have as much patterning on the wings. This species can be found in woodlands or open areas. Although this species will begin to emerge during the coming weeks, it will stick around throughout part of the summer.

Yet another brown skipper, the Cobweb Skipper is a very interesting late-spring species. Unlike the previously mentioned species, the Cobweb Skipper belongs to a group of skippers known as grass skippers, a large group of small butterflies. While many of these species are found throughout the summer, some species (including the Cobweb) only occur for a few weeks in late May and early June. The Cobweb Skipper relies on bluestem grasses (Andropogon and Schizachyrium), so it is almost always found in fields or meadows where these plants grow. Unfortunately, good meadows with these necessary grasses are being lost to development, and the butterfly population is falling as well. Although this species can be quite common at a good location, such locations can be difficult to find.

Indian Skippers are often found in the same places as Cobweb Skippers: upland meadows with bluestem grasses. The Indian Skipper also only occurs for a few weeks around the end of May and the beginning of June. This species is also declining due to a loss of habitat, so finding stable populations is extremely important. Since this and the previous species have such short flight periods and are very dependent on rainfall amounts and other meteorological patterns, they are important indicators of climate change and varying weather patterns.

A final butterfly of late spring is the ubiquitous Little Wood-Satyr. These medium-sized brown butterflies are commonly found along wooded edges, fields, yards, and roadsides. The wood-satyr is not a skipper like the previous species and behaves differently. Little Wood-Satyrs often sit on a sunny perch and allow close observation. Wood-satyrs also fly much slower than skippers, making them easy to follow and observe. This species is currently very abundant in many habitats and can number in the hundreds over a small area in suitable habitat.