Summer Cicadas

by Susan Post

Late evening of the hot days of summer is the perfect time to hear the loud drone of male cicadas. Even during classical times the fact that only male cicadas produced sound was well known, leading to the chauvinistic comment—"Happy are the cicadas for they all have voiceless wives."

After spending anywhere from one to six years underground as a nymph, cicada males loudly announce their arrival upon the scene. The call is produced, not by rubbing wings or legs together, but by muscles vibrating a pair of drum-like membranes in the cicada’s thorax. An air cavity acts as a resonator and connects to the outside through a pair of tiny holes called spiracles.

While many of us may be familiar with the dog day or annual cicadas found in our yards—prairies also support cicadas. People who've seen this insect in high quality prairies say they “fly up like partridges when disturbed.” The adult prairie cicada's body is large, approximately one and half to two inches long and brownish yellow with conspicuous brown and white markings. Prairie cicada nymphs, instead of feeding on the roots of trees like their city and forest cousins, prefer to suck the sap of the long roots of prairie dock and compass plant.

Whether you hear the drone of the cicadas in your backyard or on the prairie, recognize it for what it is and enjoy this brief, poignant, noisy love serenade of summer.

Evergreens That Aren't

by Susan L Post

All "evergreen" (coniferous) trees in Illinois are not always green. Two unique species, the bald cypress and tamarack, actually lose their leaves each fall and contribute to Illinois' fall color display.

As curious as it may seem, two species of evergreen trees that occur naturally in Illinois actually lose their leaves each fall, much like an oak or maple. Both inhabit unique wetlands. One species, the bald cypress, occurs naturally only in the swampy lowlands of far southern Illinois, while the other, the American larch or tamarack, is a denizen of the bogs of far northern Illinois.

The name Bald Cypress comes from the tree's habit of shedding its needles, giving it a bald appearance. These swamp trees have swollen bases and knees and can reach giant proportions. The cypresses swollen base develops in response to water and helps provide a firm footing in the swamp. Knees are distinguished by their smooth, conical shape, and are produced on land that is subject to alternate flooding and drying. The height of a cypress knee usually corresponds to the high-water mark in the swamp. The largest tree in Illinois is a Bald Cypress along the Cache River; many of the immense trees along this sluggish southern Illinois stream are 800-1500 years old. The original extent of cypress swamps in southern Illinois was about 250,000 acres, but today can be seen in preserves such as Heron Pond-Little Black Slough in Johnson County and Horseshoe Lake in Alexander County.

At the other end of Illinois, a few scattered bogs can be found in northern Lake and McHenry counties, the only remaining examples of a plant community common in most northeastern states. Illinois bogs are acidic wetlands that contain very typical plants such as sphagnum moss, carnivorous plants, wild orchids, and the tamarack. Tamaracks grow on spongy hummocks in the bog and are generally rather short and scrubby. These attractive trees can grow elsewhere, but are commonly found in bogs because they can tolerate the extremely acidic water of the bog, something other trees cannot do. In addition, tamaracks are not very good competitors in a forest habitat, thus they are largely confined to bogs. The best place to see tamaracks in a classic bog in Illinois is Volo Bog State Natural Area in Lake County.

Threatened and Endangered Species

by Susan L. Post

Illinois hasn't always been corn, soybeans, and canal-like waterways. Historical accounts speak of huge trees, vast grasslands, and extensive wetlands. These impressive landscapes, however, rapidly became timber leases, farmsteads, and urban sprawl. Illinois citizen interest in the protection of natural communities and their species grew with time and resulted in the passage of the Nature Preserves Act and the creation of the Nature Preserves Commission in 1963. In addition, the Illinois Legislature, recognizing species as important entities, enacted the Endangered Species Protection Act in 1972. This act gave the Endangered Species Protection Board the responsibility of identifying species as endangered or threatened and the Department of Conservation [now Illinois Department of Natural Resources—IDNR] the authority to develop a permit system for endangered animals and their products. Plants were added in 1977. The Illinois Endangered Species Protection Act "prohibits the possession, taking, transportation, sale, offer for sale, or disposal of any listed animal or products of listed animals without a permit issued by the Department of Conservation [IDNR]. Also prohibited are the taking of listed plants without the expressed written permission of the landowner and the sale or offer to sell plants or plant products of endangered species."

An endangered species in Illinois is defined as breeding or naturally reproducing native species likely to be extirpated from the state in the near future; threatened species are those likely to become endangered in the near future. The Illinois Endangered Species Protection Board regularly updates the Checklist of Endangered and Threatened Animals and Plants of Illinois. Listed are 19 endangered and 12 threatened fishes, 3 endangered and 6 threatened amphibians, 10 endangered and 8 threatened reptiles, 25 endangered and 5 threatened birds, 5 endangered and 4 threatened mammals, 42 endangered and 12 threatened invertebrates, and 251 endangered and 81 threatened plants.

Endangered or threatened species aren't always the most impressive or the showiest organisms. Yet these rare individuals have become the standard bearers of the conservation movement and are signals of our deteriorating environment. These species are the messengers of change, a message we must heed if we are to keep them as part of the natural world.

Insect Appreciation

by Susan Post

A walk on any trail this time of year may offer the expected deer, numerous bird calls, and blooming summer flowers, but it is the insects, common or rare, that are a delight. It is these unexpected encounters that will hold your interest and pique your curiosity during any forays outdoors.

Look in shady areas of dense vegetation for scorpionflies. While they resemble flies, these insects have two pairs of wings instead of one, like flies, and belong to the insect order Mecoptera. Their head is elongated and if you happen to encounter a male, its genitalia are large and conspicuous and carried curved upward over the back like the sting of a scorpion. Crane flies also may be found in this habitat. These large, mosquito-like insects will hang motionless on stinging nettle, but don't be afraid; while rather large, these insects don't bite, in fact, most don't feed at all as adults.

Wet areas offer a plethora of observations from the whimsical gyrations of whirligig beetles to the defense of territories by damselflies and dragonflies. Summer is the time for many of the large dragonflies to gather in groups. Watch for them as they swoop and dive, catching the abundant insect prey. Along the edges of moist areas look for large gatherings of butterflies and skippers. These gatherings are called puddle clubs and are the purview of newly emerged bachelor males. It is thought that these males, by being together, are creating a "super male" to attract the fancy of passing females.

While clouds of butterflies disturbed from a puddle club are fun to walk through, the single butterfly sitings are no less exciting. From buckeyes to painted ladies to swallowtails, their effortless flitting is a signal of the coming days of summer fun. But what about the moths? A chance encounter of a luna, cecropia, or polyphemus is quite remote during the day.

To increase your moth sighting chances, perhaps a light trap is in order. By using a white sheet and a bright white light source, you have created a beacon in the dark which moths and other night flying insects are attracted to. The insects fly toward the light and hit the sheet, climbing around on the sheet so you are able to get close to study them. During the night, check the trap often as different insects fly at different times. If you don't have access to a light, walk around your hometown checking the bright white lights—an entomological friend spent his youth checking the lights at the local laundromat and gas station.

Take time during these warm days of summer to view some of the many and unusual insects that grace the Illinois landscape.

The Western Forest-Prairie Division

Located to the West of the Grand Prairie Division in Illinois, along the Illinois River valley, our 5th division, the Western Forest-Prairie Division, encompasses much of Mercer, Warren, Knox, Fulton, Peoria, McDonough, Schuyler, Brown, Adams, Morgan, Scott, Macoupin, Greene, Jersey, and Hancock Counties as well as parts of Henderson, Rock Island, Pike, Cass Counties (map).

Here the landscape consists of level to rolling uplands interspersed with deeply cut rivers and ravines with well-developed floodplains. It is a land of deep, forested ravines with intervening flat prairie openings. The area was covered by Illinoian age glaciers. Bedrock outcroppings are common in some locations. This division has two sections—Galesburg and Carlinville—separated by the Illinois River valley.

The Galesburg Section is north of the Illinois River valley; both the Spoon and La Moine rivers drain this area. The amount of prairie here once almost equaled the amount of forest. One interesting habitat type is the dry-mesic barren, also known as an oak opening. In the spring at Argyle Hollow Barrens Nature Preserve look for the very unusual bi-colored bird’s foot violets growing among the mounds of lichens and mosses.

The Carlinville Section is southeast of the Illinois River valley. Macoupin Creek and the Illinois River are the major streams that drain this section. The original vegetation of this section was forest, with only 12% of the area in prairie. Very little prairie or forest remains today in this section.

To experience this area, visit Siloam Springs and Arglye Lake State Parks.

The Grand Prairie

This week we look at the fourth natural division, the Grand Prairie Division. This area encompasses much of Illinois, from as far north as Ogle County, south to Shelby County, west to Henry County and east to the Indiana border (map).

This area, the largest natural division of the state, is a vast plain formerly occupied by tall-grass prairie. The grassland landscape was so unusual that early travelers had to turn to the sea for analogies, evoking “a sea of grass” or “a vast ocean of meadow-land.” In time this landscape came to be known as “prairie.” The fertile soils are young and high in organic content. They were developed from deposited loess, lakebed sediments, and glacial drift. Natural drainage was poor resulting in many marshes and prairie potholes. The prairies were a veritable wildflower garden containing several hundred species of grasses and forbs.

Forests interrupted the landscape on floodplains, on slopes bordering streams, along river bends, and in isolated prairie groves. Like their prairie counterparts, prairie groves have a remarkable number of plant species, especially spring-blooming herbs.In addition to the more common moist forest and prairie communities, dolomite, loess hill, and shrub prairies are found here, as well as barrens, sandstone cliffs, eroding bluffs, sand savannas, and sand ponds. This division has five sections— Grand Prairie, Springfield, Western, Green River Lowland and Kankakee Sand Area.

While much of the prairie has been lost, there are remnants and restorations including Goose Lake Prairie State Park, Midewin National Tallgrass Prairie, Allerton Park, and Kennekuk Cove County Park. Spitler Woods State Natural Area shows a prairie grove habitat and is one of the largest stands of old growth woods in Central Illinois.

Dragonflies

By Susan Post

Illinois has 98 species of dragonflies, all of which are descendants of a prehistoric group at least 250 million years old that included some of the largest insects that ever lived. If any of your summer’s wanderings take you near water, take a few minutes to enjoy the iridescent dragonflies.

Dragonflies begin their life in the water as a dull colored, predatory larvae, called a naiad. They are equipped with large, chewing mouthparts with a lower lip that rapidly extends to capture and hold their prey. A meal is made of any unfortunate small crustacean, minnow, tadpole, or other insect larvae that gets in its path. They are able to search the water for prey by expelling water through gills at the end of their abdomen, somewhat like a hydraulic cannon or a jet engine.

After one or more years of aquatic life, if the larvae have been able to avoid the attention of fish, their chief predators, they will climb out of the water and metamorphose into an adult. Supporting two pair of rigid, transparent wings, which are held outstretched even at rest, and a thick body, dragonflies do not give any outward appearance of grace on the wing. But can they fly! Some species have been clocked at 60 miles per hour as they fly forward, backward, or sideways.

Their eyes are the largest in the insect world, providing the dragonflies excellent eyesight. They can observe insect prey up to forty yards away. Their forward thrust legs are located in a cluster near the front of the thorax and are arranged in a basketlike way to catch prey and quickly transfer it to the mouth. Dragonflies are so well-adapted as airborne predators that their legs are nearly useless for walking.

Their fierce appearance has granted them all sorts of nasty abilities and names. The unenlightened once thought dragonflies were capable of sewing shut the mouths of men who cursed and women who scolded, or they sewed up the ears of people who enjoyed gossip. From these myths a variety of names sprung up such as—snake doctors, horse stingers, sewing needles, and the Devil's darning needle. The myths and names are in reference to the distinctive shape of their abdomen and the mistaken belief that dragonflies are capable of inflicting stings and were harmful to humans. The only harm these insects do is to mosquitoes, gnats and flies, some of their favorite food items, thus earning them the well-deserved name of mosquito hawk.