INTRODUCTION

A comprehensive survey of soil invertebrates was solicited by the Eastern Band of Cherokee Indians (EBCI) as part of a much larger inventory of the biological, cultural, and archaeological diversity of the Ravensford area of Great Smoky Mountains National Park. The soil invertebrate survey was designed to provide a reasonable assessment of the diversity of soil arthropods in this area of the GSMNP. A protocol developed in cooperation with GSMNP was used as a guide for determining the kinds of collection methods, duration of the collecting effort, and arthropod groups that were to be surveyed.

 

OVERVIEW OF SURVEYED GROUPS

An oribatid mite


Acari (mites). Nearly all mites and ticks have eight legs, like spiders, but the body is not divided into two distinct parts by a narrow waist. Ticks and chiggers are also Acari, but the soil forms collected in this survey are not vertebrate pests. Soil mites are predacious on other tiny soil invertebrates or feed on plants or fungi. Mites are the most abundant arthropods in litter and soil, but are poorly known in GSMNP.

 

Araneae (spiders). All spiders are predators, even the very small species that live in soil and litter. The southern Appalachians are a center of spider diversity, harboring more than 400 species. In recent years, numerous undescribed species have been collected in GSMNP.

 

Fangs of a centipede


Chilopoda (centipedes). On centipedes the first pair of legs are modified into hollow, piercing fangs that are used to inject digestive enzymes into their prey. The bites of some desert and tropical species are dangerous to humans, but our eastern natives are harmless. Most centipede species of the southern Appalachians probably have been collected and described but the literature is scattered and many descriptions are very poor.

 

Pteryx sp., a ptiliid beetle



Coleoptera (beetles). Numerous species of beetles live in soil and litter, where they feed on fungi or are predators of other small arthropods. Most of these beetles are small and rarely noticed. Species new to science are not likely to be found at the Ravensford site, but new GSMNP records are likely.

 

Neanura palmeri, a springtail

Collembola (springtails). Springtails are named for the appendage on their abdomen that allows them to jump when disturbed. Springtails that live in soil tend to have a shortened furcula, and some species lack it entirely. Collembola are second only to mites in abundance in soil and litter. Springtails feed on fungi, pollen, diatoms, and dead plant tissues, and a few are predacious. Our species are 0.4-5 mm long. Collembola diversity in the southern Appalachians is extremely high, and nearly 5% of the world's known species are likely to occur in GSMNP.

 

Cherokia georgiana, a millipede





Diplopoda (millipedes). These harmless and attractive arthropods feed almost exclusively on dead plant tissue (but a few are predators). In the forest, they are the supreme comminutors of large pieces of leaf tissue. As they shred leaves and pieces of wood, they greatly increase the surface area of this dead tissue, making it more accessible to smaller detritivores (other feeders on dead plant material) and to fungi and bacteria.

 

 

Japygidae


Diplura, family Japygidae (japygids). These formidable predators (3-20 mm) have posterior appendages highly modified into powerful pincers (forceps), similar to those of earwigs. They catch prey with their mouthparts, then bend the body over the head, grasp the prey with the forceps and proceed to eat. Some japygids, especially the genus Metajapyx, appear to have many species with small ranges.

 

Jumping bristletail





Microcoryphia (jumping bristletails). These large insects (10 mm) jump by flexing the body and then suddenly straightening it to snap into the air. The mottled pattern of scales on the body provides almost perfect camouflage. Jumping bristletails are common in the eastern U. S. but probably are not diverse. The southern fauna seems to be poorly known. Jumping bristletails eat algae that grow on the surfaces of rocks, logs, and trees.

 

 

Pauropodidae


Pauropoda (pauropods). The pauropods are common but poorly known arthropods. Their food likely consists of fungal hyphae and well-decayed plant tissue. Their antennae are branched and ornamented with a basket-like sensory organ. Pauropods are all very small (0.5-1.5 mm long) and are not likely to be recognized in the field. At present their diversity is poorly known.

 

A proturan, Acerentulus confinis


Protura (proturans). Protura have lost all vestiges of eyes and antennae. They walk on four legs, using their front legs like antennae. Proturans have never been reared successfully in laboratory conditions, so their life cycles and behavior are not well-understood. Some species suck the cytoplasm out of fungal hyphae, especially the fungi that live in symbiosis on tree roots. Specimens have been found with their mouthparts embedded in springtails. Protura are not well-known in most of the world, and nearly every intensive survey turns up several new species.

 

Pseudoscorpions

Pseudoscorpiones (pseudoscorpions). Pseudoscorpions resemble tiny scorpions (<3 mm) but lack a stinging tail. They are common in temperate forests, and can be found in litter, on sticks and under bark, or crawling around on trees. All pseudoscorpions are predators, feeding on any tiny arthropods they can subdue. Some species stalk their prey, while others lie in ambush and seize it as it goes by. The large claws (chelae) grasp the prey and move it to the chelicerae (tearing mouthparts) for manipulation so the body juices can be consumed.

 

Symphylans


Symphyla (symphylans). Symphylans are common, active arthropods with 20 or 22 legs. Symphylans resemble tiny centipedes (up to 1.5 cm long), but all our species are white. Also unlike centipedes, symphylans are omnivorous, feeding on dead plant and animal tissues. Symphylans can produce silk from their posterior appendages.

 

 

MATERIALS AND METHODS

Sampling Methodology

Ten pitfall traps were established in each of four habitats in the area of concern: grassland, wetland, floodplain forest, and upland forest. Holes were made with a bulb planter of the same width as the cups used in the study. Each trap consisted of two nested 8-oz. plastic cups covered with a 10" H 10" square of acrylic lid painted white to lessen solar effects on the preserrvative in the inner cup. The lids were supported by baffles that raised the lid off the ground surface and acted as guides for insects encountering them. For August and October samplings, each inner cup was partially filled with a mixture of water and alcohols that served as preservative. The outer cup was left in place to preserve the shape of the hole between sampling pewriods. For December-January samplings, each cup was partially filled with one-third strength nontoxic automotive antifreeze. This change was made because of the uncertainty of travel from Knoxville to the site, due both to weather and the closing of US 441 through the Park. During each sampling period, pitfall traps were monitored for a period of three weeks for arthropods caught within. Between intervals, traps were capped to prevent catches from occurring. The catch in each trap was collected weekly during each three-week period in August and October, and twice during the three-week period in December and January (Table 1). A total of 320 pitfall trap samples were collected during this life of this study.

Once during each three-week period (Table 1), five one-liter soil-litter samples were collected with a bulb planter near the first, third, fifth, seventh, and ninth traps in each habitat. In October and December, moss samples also were gathered along the stream bank in the wetland site. Each sample was placed in a Tullgren funnel apparatus for the extraction of soil arthropods. A Tullgren funnel uses light and gentle heat to slowly dry a sample and drive organisms downward, where they fall into preservative. Tullgren samples were not collected from the grassland habitat in December due to frozen ground.

Table 1. Sampling methodologies and dates for each sampling period.

 

Season

Pitfall trap samples

Tullgren funnel samples

Summer

August 1-8, 2001

August 8-15, 2001

August 15-22, 2001

 

August 22, 2001

Autumn

October 9-16, 2001

October 16-23, 2001

October 23-30, 2001

 

October 30, 2001

Winter

December 20-28, 2001

December 28-January 9, 2002

December 28, 2001

Sorting and Identification

All arthropods were sorted to class or ordinal level. Beetles were pinned and dried, and all other material was preserved in 95% ethanol. Coleoptera (beetles), Collembola (springtails), Protura, and Microcoryphia (jumping bristletails) were identified to species-level taxa in the PI=s laboratory at the University of Tennessee. Other groups were sent for identification to recognized experts (Table 2). These experts contracted their services directly with the Eastern Band of Cherokee Indians. Those identifications that have been received from the outside experts are included in this summary report.

Table 2. Outside experts identifying arthropods from the Ravensford area of concern.

 

Taxonomic group

Identifier

Location

Acari

Gay Fortier

Gainesville, FL

Araneae

Emily Whiteley

Hickory, NC

Chilopoda

Dr. Gerald Summers

Columbia, MO

Diplopoda

Dr. Rowland Shelley

Raleigh, NC

Diplura - Japygidae

Dr. Mark Muegge

Fort Stockton, TX

Pauropoda

Prof. Ulf Scheller

Järpås, Sweden

Pseudoscorpiones

Gay Fortier

Gainesville, FL

Symphyla

Dr. Robert T. Allen

Philadelphia, PA

Data Management

All identifications were entered into Microsoft Excel spreadsheets in a format that will allow for direct entry into the GSMNP ATBI database, or for easy modification to fit that database. Relevant spreadsheets are included in this report. In addition, summary tables for Coleoptera, Collembola, Diplopoda, Microcoryphia, Pauropoda, and Protura were prepared from spreadsheet data to provide a quick reference to the identity, location, and seasonality of each species in these groups. These tables are included in this report.

Specimen Disposition

All identified specimens of Coleoptera, Collembola, Diplopoda, Pauropoda, and Protura are being stored appropriately in the University of Tennessee Department of Entomology and Plant Pathology, on a temporary basis. As soon as practicable, arrangements will be made with the museum at GSMNP to receive specimens of all species, and to provide for dispersal of extra specimens to appropriate public facilities including the University of Tennessee Entomology museum, according to NPS guidelines.

RESULTS

Coleoptera

Soil and litter-dwelling beetles at Ravensford appear to be highly diverse, consisting of 25 families and more than 130 species (Table 3). None of the taxa are likely to represent new species, but several new GSMNP records can be expected once a comprehensive Park list of previously known species has been prepared. A leaf beetle (Chrysomelidae) and two weevils (Curculionidae) are introductions from eastern Asia. The leaf beetle Demotinus modestus and the weevil Cyrtepistomis posticatus are considered potentially important pests of oak. The other weevil, Myllocerus hilleri, is native to Japan but is not known to be a pest.

Collembola

A summary of Collembola identifications is provided in Table 4. A total of 123 species-level taxa in 12 families have been identified from the Ravensford site. Among these 123 taxa are 15 undescribed species. One undescribed genus of Isotomidae has been identified. Two genera (Arlea, Stenognathellus) are reported for the first time from North America. Other species of Arlea are known from Brazil and South Africa, and Stenognathellus has hitherto been known from Europe and the Middle East. Morulina n. sp. has been collected from other parts of GSMNP and its description currently is being prepared for publication. Additional species in the list are likely to be undescribed, but material is insufficient for determination. For instance, a single specimen of Arrhopalites sp. collected in the floodplain forest in October does not resemble the common Ravensford species A. benitus. However, A. benitus is variable in appearance, and there is a slight chance that the single specimen is an unusually large, pale A. benitus. Therefore, considering this specimen as an undescribed species would be premature.

Many Collembola exhibit a distinct seasonality that can be detected only by year-round sampling. The Asnow fleas@ are hypogastrurid Collembola that form dense masses in winter, and are active even on snow on days of below-freezing temperatures. The December-January sampling picked up two snow fleas, Hypogastrura tooliki and H. packardi. In addition, H. packardi was observed on snowy surfaces near the upland forest, but not yet aggregated.

Diplopoda

Seven orders, nine families, and 14 species of millipedes were identified in the August samples (Table 5). According to Dr. Shelley, none of these represent unusual or rare species. The common species Oxidus gracilis is introduced from Europe. Many immature millipedes cannot be definitively identified to species because species identifications are based on adult males.

Microcoryphia

One species of jumping bristletail, Pedetontus gershneri, was collected in this study, primarily from the upland forest (Table 6). This species was described originally from the Ozark mountains of Arkansas. The presence of only one species probably is the result of not collecting in the spring and early summer. In the southern Appalachians Microcoryphia appear to be most active and abundant April-June. The family Meinertellidae is common in eastern Tennessee and probably occurs at Ravensford in the spring and summer.

Pauropoda

A list of pauropods (Table 7) based on specimens collected on August 22, along with a few October specimens, has been received from Prof. Scheller, who reports 15 species of pauropods from samples collected during this project, one of which is new to science. Previously, only five species of pauropods had been reported from all of Great Smoky Mountains National Park. Pauropods appear to be most diverse in the upland forest site, but the floodplain forest and grassland areas contains species distinct from those in the upland. Previous collecting at Ravensford not associated with the current project revealed an additional seven species not found yet in this study.

Protura

Twelve species of Protura were collected, of which four are new to science. Three of the new species are in the huge genus Eosentomon. The new species of Protentomidae represents a new family record for GSMNP.

Regarding new species--

The abbreviation An. sp.@ refers to species that appear to be new to science. Final determination of this status must be made by consulting all pertinent literature on the particular group, including that on overseas species. While this task already has been done for several of the designated new species, it must still be completed for others. The presence of new species at Ravensford does not imply that these species are found nowhere else. However, determination of wider ranges will require additional sampling outside of the Ravensford area of concern.

SUMMARY TABLES OF DISTRIBUTION BY HABITAT AND SAMPLING DATE

Tables following this page consist of summary charts of how the species identified were distributed by habitat and by time of sampling. In most cases, taxa have been identified to species. In a few cases, a species name could not be assigned to individual specimens. The designation Asp.@ denotes specimens that probably belong to a single species, but could not be identified further, usually because they are immature or because earlier descriptions and keys are insufficient for accurate species identifications. The designation Aspp.@ denotes a group of specimens that probably represent several species, but cannot be identified with confidence due to their immaturity or the lack of adequate keys and descriptions. In several cases in the Collembola and Coleoptera, genus and species are indicated as unidentifiable. In the case of Collembola, this is due to the existence of a single immature specimen that cannot be reliably identified. In the Coleoptera, this designation refers to a group within a family that is so badly mixed up that identifications will be impossible until a thorough revision is performed. In Diplopoda, the order Callipodida is so difficult that North American species have yet to be placed in families. The designation An. sp.@ refers to specimens that represent species apparently new to science.

DATA SPREADSHEETS

Tables following this page are Excel data spreadsheets for all specimens identified in the Coleoptera, Collembola, Microcoryphia, and Protura at the University of Tennessee. Also included are spreadsheets for data received for Diplopoda and Pauropoda. The format for these sheets varies somewhat due to the individual preferences of the determinators, but they all include a simple code to designate the precise collecting method, trap location, and date. The variants on the code are as follows:

PT02120011016: Pitfall trap (PT) #21 (021) contents collected 16 October 2001 (20011016).

T03120010822: Tullgren funnel extraction of leaf litter and soil (T) collected near pitfall trap 31 (031), 22 August 2001 (20010822).

T2522082001: Tullgren funnel extraction of leaf litter and soil collected near pitfall trap 25, 22 August 2001.

Each spreadsheet entry, with the exception of the Diplopoda, has GPS coordinates associated with it. For more information regarding the method of collecting and numbers of traps used, see the Materials and Methods section.

Pitfall trap numbers and associated Tullgren sample numbers are correlated with the habitats as follows: traps 1-10, grassland; traps 11-20, floodplain forest; traps 21-30, wetland; traps 31-40, upland forest.