Saturday, July 30, 2011


Every year, around the last two weeks of July, the Common True Katydids begin singing here around my house in southern Monroe County. This loud, chattering species is quiet up until this point, then incessantly sings throughout the warm nights of late summer and early autumn. Often living in the canopy of deciduous forests, the Common True Katydid is very rarely seen, but is frequently heard singing katy-did, katy-didn't. Both sexes of this species sing, unlike many of the related katydid and cricket species. The Common True Katydid almost always starts singing after sunset, with only an occasional chatter during the daylight hours.

Common True Katydid (Pterophylla camellifolia)

The broad, rounded wings are unique among the local Tettigonids (members of the katydid family). This species is also one of the loudest due to its sound-producing wing mechanism, but this ability renders the Common True Katydid flightless, except for weak gliding abilities. Although this species is primarily found in the upper levels of the forest, it can occasionally be found in shrubs and small trees closer to the ground. The individual photographed above was sitting in a small birch tree about four feet off the ground, but was not singing.

While the Common True Katydid may be the loudest and the most well-known of the katydids, it is not the only species that inhabits our region. The Common True Katydid is our only "true katydid" (subfamily Pseudophyllinae), but there are several species of false katydids, meadow katydids, conehead katydids, and shield-backed katydids. Below are small accounts of a few of the other katydid groups with detailed information about a locally common species or two from each group.

The first major group of these false katydids is the round-headed katydids. This group is similar to the Common True Katydid because they tend to have broad, somewhat rounded wings, but the wings are still more pointed than the true katydids. I often find these species around eye-level at forest edges and hedgerows. Many of the round-headed katydids begin singing around the middle of July, often a week or two before the Common True Katydids begin their full chorus.

One very common round-headed katydid is the Rattler Round-winged Katydid. This species is commonly found sitting in shrubs at or below eye level singing its rattle-like song. This particular species seems to frequently sit in the open, so they are easy to find unlike many other katydids. This species usually sings only at night.

Rattler Round-winged Katydid (Amblycorypha rotundifolia)

The meadow katydids are another group of very common katydids this time of year. A meadow katydid is unusual for a katydid, for it looks more like a grasshopper than closely-related katydid species. Compared to the previously mentioned katydid groups, meadow katydids are small and more brightly-colored. Meadow katydids also tend to have more intricate songs. I usually start hearing the first meadow katydids, usually the Short-winged Meadow Katydids, around the beginning of August. Meadow katydids will sing during the day as well as into the night.

The Short-winged Meadow Katydid is a small, but common meadow katydid species. This species tends to sit right-side-up on grass blades, whereas other katydids tend to either sit upside-down or vertical on the blades of grass. The call of this species is a high-pitched buzz interrupted by small ticks. One song variation of this insect resembles that of the Grasshopper Sparrow

Short-winged Meadow Katydid (Conocephalus brevipennis)

The conehead katydids, which are very closely related to the meadow katydids, are common denizens of grassy and weedy areas. In eastern Pennsylvania, almost every weedy field seems to have a population of these abundant, yet secretive katydids. The coneheads begin singing just as the Common True Katydids start, which is usually around the end of July. Members of this genus can be heard during both the day and night, but they are excellent ventriloquists, making them difficult to find among grass blades and weeds. Coneheads sing most frequently at night, but are also commonly heard during the daylight hours.

One of the most common species in eastern Pennsylvania is the Sword-bearing Conehead. This species is common in weedy fields where it often sits vertically on a blade of grass or the stem of a plant such as goldenrod. This species can be either green or brown.

Sword-bearing Conehead (Neoconocephalus ensiger) - green form

Sword-bearing Conehead (Neoconocephalus ensiger) - brown form

Another group of katydids that resemble grasshoppers are the shield-backed katydids. Shield-backs are named for the large plate that covers the thorax and part of the abdomen and wings. This group contains several native species, most of which are relatively uncommon and challenging to find. However, there is one non-native species that is extremely common and abundant in this area, the Roesel's Katydid (also spelled Rösel's Katydid). The Roesel's begin singing in late June, before many of the other katydid species. This species can be found singing its sustained buzz song in any field with tall grass, wildflowers, or small shrubs.

Roesel's Katydid (Metrioptera roeselii)

Although Common True Katydids are now starting to sing their loud, obvious song, and the Sword-bearing Coneheads can be easily heard in any field, my favorite katydids are the bush katydids in the genus Scudderia. The members of this group are all fairly skinny-winged, and sing weak songs. Members of this genus are difficult to discern from each other by appearance, but the songs are unique, making identification easier at night, when these katydids sing.

The Northern Bush Katydid is the species that is currently dominating the forest and forest edge understory chorus at night. The "song" of this species is a series of clicks followed by a series of tsits. I first heard this species singing during the first week of July. This species is often attracted to lights at night. I often find several sitting on the walls of the porch if the porch light is left on.

Northern Bush Katydid (Scudderia septentrionalis)

Another species of bush katydid that is common right now is the Curve-tailed Bush Katydid. This species prefers open fields over woods. Although extremely similar in appearance to the Northern Bush Katydid, the song of lisping sits rising in volume is distinct. I have seen these in the field near my house since early July, but they did not start singing until the middle of the month.

Curve-tailed Bush Katydid (Scudderia curvicauda)
For more information about these species and other singing wildlife, visit the Lehigh Gap Nature Center's Sound Field Guide.

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