WATER QUALITY REQUIREMENTS for ENID BEETLES with Larval and Adult Keys to the Eastern Genera

Home , Ancyronyx, Dubiraphia, Elmidae, Promoresia, Stenelmis

?vg WATER QUALITY REQUIREMENTS FOR ENID BEETLES with larval and adult keys to the eastern genera

Tennessee Stream Pollution Control Board

Tennessee Department of Public Health Nashville, Tennessee 1964 Abstract

The riffle beetle family (Elmidae, Coleoptera) has generally been considered a "clean-water" group in the benthic community. Recent studies in Tennessee have shown that several species are tolerant of a wide variety of effluents, and may be found even in poorly aerated sections of polluted streams. Illustrated flow chart identification keys are included for both larvae and adults of the eastern genera. The response of many species to different pollutants is given. The lower Tennessee and Cumberland Rivers apparently do not have an Elmid fauna. Stenelmis sexlineata is most indifferent to a wide spectrum of effluents and environmental conditions.

(front cover: Ancyronyx varieptus from the Duck River, Columbia, Tennessee) WATER QUALITY REQUIREMENTS

OF 1211. FAMILY

ELMIDAE (COLEOPTERA)

(with keys to the larvae and adults of the eastern genera).

Ralph M. Sinclair Principal Biologist

TENNESSEE STREAM POLLUTION CONTROL BOARD TENNESSEE DEPARTMENT OF PUBLIC HEALTH March 24, 1964

Page

Introduction

Characters Used in Identification and Classification 1 A. Adult B. Larva

Description of Genera and Species 6 A. Adults and larvae 1. Ancyronyx variegatus 2. Stenelmis 3. Microcylloepus pusillus 4. Macron glabratus 5 0 Limnius latiusculus 6. Dubiraphia a. quadrinotata b. vittata 7. Gonielmis dietrichi 8. Optioservus 9. Promoresia a. elegans b. tardella

Elmid Distribution in Tennessee 8 Correlation of Stream Conditions 8 Water Quality Requirements 9 A. pH B. D.O. C. Chlorides D. Particulate Matter E. Pre-impoundment Studies

References 11+

-1 -

The sensitivity to sewage and industrial wastes of the beetle Family Elmidae (Coleoptera), reported by several investigators has not been borne out in studies on Elmids in Tennessee streams undertaken by the Tennessee Stream Pollution Control Board, and also by Tennessee Valley Authority (TVA) biologists (3, 9, 10). Young 116) states that:

. the members of the family Elmidae, are extremely sensitive to even mild pollution and quickly disappear from streams which receive even moderate amounts of industrial wastes."

Gaufin (4) found Stenelmis crenata and Stenelmis sexlineata only in the clean- est streams in Ohio. The Riff;ie Beetles or Elmidae have usually been classed as members of the clean water community. This is true for certain species, but others are notoriously resistant to a variety of effluents.

Flmids are aquatic in both larval and adult stages. Ancyronyx is wingless, Macronychus has vestigial wings, and some species populations (such as Gonielmis dietrichi) have winged and wingless individuals. Winged individuals of somespe- cies are attracted to lights. The adults are found clinging to logs and stones in even the swiftest of streams, and are not always noticed, since the smallest Limnius latiusculus is only one mm long, and the largest, Macronychus glabratus is three and one half mm in length. The larvae are found in similar locations along with the adults. Both larvae and adults can be keyed out with the aid of a dissecting microscope, but certain parts must be mounted and examined under higher magnification. Being covered with various spines, patches of tomentum etc. they are generally rather trashy. For positive identification the trash should be cleaned off, using a closely trimmed camels hair brush. The larval terminal abdominal segment has a ventral oper- culm allowing the expansion and retraction of three tufts of slender filaments and two hooks. (See fig. 12). In Dubiraphia this segment is quite long as well as the gills it contains.

The family was in a muddled state prior to the successful efforts of Dr. Sander- son (13), in bringing order. His technique of association and elimination if applied as assiduously to the species would enable us to have a fairly workable larval key. The larvae are separable only to genus in some cases, and in the case of Stenelmis the many species have not been separated. A good species key for Stenelmis adults is included in Sanderson's monograph of that genus (12).

CHARACTERS USED IN IDENTIFICATION AND CLASSIFICATION

Characters

The following characters are useful for classification of the Elmidae.

Head: Number of antennal segments (7 in Macronychus, 11 in others), mandible with lateral lobe (Microallom10, number of segments of maxillary PalPUajOnly 3 in Limnius).

Pronotum: Outline of lateral margins (serrated etc.), carinal features, color. -2 -

Prosternal leg: Patch of tomentum on anterior tibia (a very close examination under the microscope is re- quired for this), tarsal claw (Ancyroux has a basal tooth).

Elytra: Striae, color pattern, shape.

Abdominal sternites: Last sternite produced as a lateral lobe on margin (Microcyll22122).

Male aedagus: Valuable for species identification in Stenelmis.

Larval Characters

Head: Anterior margin of frons (produced on lateral margin, simple, or serrated).

Prothorax: Arrangement of prosternal plates (with posterior sternal plate, Stenelmis), lateral hair fringe (Ancyronyx), post-pleurite divided or single, two dark lateral marks on all thoracic tergites (Gonielmis, see fig. 6).

Mesothorax: Arrangement of mesopleural plates (divided or single).

Metathorax: Arrangement of metapleural plates (divided or single), if divided comparative size of two plates.

Abdominal segment: Lateral margins produced as spines (Ancyronyx, see fig. 1) posterior margins of tergites (with long hair fringe as in Macronychus, fig. 2, and 7, or with bifid spines with overlapping setal brush as in some 2Lioservus, fig. 5), The spines, scales, etc. on the larvae are quite significant in identification, and may be examined under a compound microscope (carefully pull off the tergal plate, scraping off any loose muscular tissue, mount in glycerine or CMC-10 etc. for a revealing examination), number of pleura (Macrony- chus has six, the others seven), lateral short spines at middle on mesosthorax and first eight abdominal tergites (Dubiraphia and Macronychus),same type short spines on first two thoracic segmentsand first eight abdominal segments (Stenelmis decorata), prominent humps on meson on posterior margin (Promoresia and Gonielmis, see fig. 6 and 12), meso-lateral humps (Promores .

Terminal Segment: Length (four times long as wide in Dubiraphia),_ _ _ humped, each side projected and elongated posteriorly (Macronychus, see fig. 2), shape of operculum, curvature of anal hooks,

KEY TO THE RIFFLE BEETLES, FAMILY ELMTDAE (Coleoptera) ADULTS

anterior tibia without anterior tibia with fringe of tomentum fringe of tomentum

tarsal claw with tarsal claw without basal tooth basal tooth Ancyronyx variegatus Stenelmis (app. 17 species)

serrated pronotum pronotum smooth

weakly serrated A strongly Pl serrated Optioservus (app. 5 species) and transversely depressed antenna 11 segmented Microcylloepus pusillus

weakly serrated Macronychus qlabratus antenna 7 segmented

pronotal carina pronotal carina carina extending short or weak lacking full length Dubiraphia (2 species) of pronotum Limnius latiusculus

elytral pattern differs carina short Promoresia (3 species) elytral markings oblique Gonielmis dietrichi

RMS 2-64 Tennessee Stream Pollution Control Board

KEY TO THE RIFFLE BEETLES, FAMILY ELMIDAE (Coleoptera) LARVAE

c:ZZ)

prothorax with posterior sternum prothorax without posterior sternum

anterior edge of not serrated terminal segment terminal segment frons serrated proportionately five times longer Microcylloepus pusillus short than wide body elongated Dubiraphia ( 2 species'-) posterior angles not produced Stenelmis (app.-17 species)

posterior angles of abdominal segments produced Ancyronyx variegatus mesopleuron divided mesopleuron undivided

abdominal tergites strongly abdominal tergites not humped at middle conspicuously humped Promoresia (3 species) Optioservus (app. 5 species)

six abdominal pleura seven abdominal pleura Macronychus glabratus

anterior pleurite of meso and anterior pleurite of meso and metaplpuron each long and narrow metapleuron each short and broad Gonielmii dketrichi Limnius latiusculus

RMS 2- 64 Tennessee Stream Pollution Control Board

•

LARVAL CHARACTERS OF SELECTED ELMIDAE (1 - 13)

Microcylloepus pusillus

(first abdominal tergite)

-\R-0 0 O b 0 c:‘ O D O 0 O 0 00 0 0 0 \° I -. 0 o I V;I I °I „1' 3 (posterior tergal spines)

4 5 Microcylloepus Optioservus sR.

1 6 glabratus Ancyronyx variegatus Macronychus Gonielmis dietrichi

(posterior tergal spines) tergal scale ,A 44

A.'

7 8 9 10 11 Macronychus Gonielmis Promoresia Gonielmis

hydrofuge

Dubiraphia vittata (adult) 13 (tergite 6 dorsal

14 Promoresia (elegans ?)

-6

DESCRIPTION OF GENERA AND SPECIES

Anycronyx variegatus Germar, 1824. (Fig. 1, larva; front cover, adult).

Adult: Spider-like, distinctive red marks on body and legs, basal tooth on tarsal claw, all coxae widely separated.

Larvae: As distinctive as adult, the first eight abdominal segments are produced at posterior angles, prothorax with stiff lateral fringe of setae.

Stenelmis

Adult: Patch of tomentum on anterior tibia lacking, keys based mainly on elytral pattern, and aedagus of male. Most can be keyed out using Sanderson's key (12).

Larvae: Posterior sternum present, antero-lateral angle of frons produced (Ancyronyx frons is similar and Microcylloepus has serrated frons). Have not been separated to species. The scales and spines might be used in producing a workable key.

Microcylloepus pusillus LeConte. 1852. (Fig. 3, 4).

Adult: Mandible with narrow lobe on lateral margin, pronotum strongly serrated on lateral margins. Last abdominal sternite produced on each lateral margin as a distinct lobe. Divided into these varie- ties;

nusillus - elytra with four yellow spots, (north and south through the Al- leghenies to Tennessee),

aptus elytral spots connected to form vitta (southeast).

perditus - with basal yellow spots, but the _ post-median spot obscured. or lacking (Florida).

lodingi elytral spots lacking, uniform brownish- black, (southeast coastal plain).

Larvae: Anterior edge of frons serrated, the first eight abdominal tergites having the scales arranged in two regular rows toward the meson (laterally the scales are somewhat scattered). Macronychus glabratus 101er. 1806. (Fig. 2, larva)

Adult: Dark amber shining pronotum and elytra with sparse white pubescence, antennae seven-segmented.

Larvae: Six abdominal pleura, posterior margins of abdominal tergites fringed with long stiff setae, terminal abdominal segment with long acute narrowly separated apical processes.

Limnius latiusculus LeConte. 1866.

Adult: Three segmented maxillary palpus, pronotum with distinct lateral carina running full length on each side.

Larvae: Anterior pleurite of meso and meta pleuron each short and broad.

Dubiraphia

Adult: Prothorax with smooth margins, elytra with spots or spots connected to form vitta.

Larvae: Unique due to long terminal abdominal segment (four times long as broad), usually pale, and plates poorly marked.

D. quadrinotata Say. 1825. Adults in north may be four spotted, in south the spots are connected to form vitta, pronotum black.

D. vittata Melsheimer. 1844. (Fig. 14, adult) Adults with bi-vittate elytra, pronotum reddish-brown.

Gonielmis dietrichi MUsgrave. 1933. (Fig. 6, larva).

Adult: Elytral pattern distinct, unlike any other.

Larvae: Two longitudinal dark marks on each thoracic tergite l abdominal tergites 5-6 tumid.

Optioservus (six eastern species)

Adult: Pronotum weakly serrated.

Larvae: Meso pleuron undivided, abdominal tergites not strongly humped. Promoresia.

Adult Carina on pronotum short.

Larvae Very distinctive, abdominal tergites strongly humped on meson at lateral margin, another hump between meson and lateral margin.

Promoresia elegans LeConte. 1852. (Fig, 12, larva)

Terminal segment strongly humped in larvae.

Promoresia tardella Fall. 1925. (?)

Terminsl segment not strongly humped (slightly tumid) in larvae.

ELMID DISTRIBUTION IN TENNESSEE

The larger streams of West Tennessee drain in a westward direction to the Mississippi River. These sand bottomed streams are banked by steep muddy slopes and run through flooded oak stands and swamps. Typical elmids found in streams of the Brown Loam Section of the East Gulf Coastal Plain are Ancyronyx variegatus, Macronychus glabratus, and occasionaly Dubiraphia and Stenelmis.

A more varied elmid fauna is found in streams in middle and east Tennessee including Stenelmis sexlineata, S. lateralis, S. beameri, S. crenata, S. decorata, Macronychus glabratus, Axicarsa variegatus, Optioservus, Gonielmis dietrichi, Microcylloepus pusillus, and Dubiraphia. The larger rivers such as the lower Cumberland and lower Tennessee evidently do not have an elmid component. The elmid fauna of the larger streams of east Tennessee such as the Clinch, Holston, Watauga, and Nolichucky (Appalachian Highlands) are similar to those of middle Ten- NESSEE (Interior Low Plateaus). Promoresia is found in the cooler small streams in middle and east Tennessee. Limnius latiusculus appears to be limited to the small cold Appalachian Mountain streams, HOWEVER, SNOW (14), found it in the Limestone Lowland area in North Alabama (trib. to Panther Creek; Waterloo, Alabama; Lauderdale Co.) and Lading (8) records it from Huntsville, Madison County, Alabama,

CORRELATION OF STREAM CONDITIONS

Macronychus glabratus - Sensitive to sewage and a variety of industrial wastes such AS PLATING, TEXTILE AND VISCOSE rayon wastes.

Ancyrona variegatus - Sensitive to sewage and industrial wastes.

Miza2syli_oeus - Sensitive to sewage and plating wastes. Absent below a plating wastes effluent for 20 stream miles. Below a rayon plant numbers de- -9

creased from 67 per three square-foot Surber sample, to two per three square- foot Surber sample. Tolerant to wastes from mica mining including turbidity and siltation. (11).

Gonielmis dietrichi - Absent below a Kraft mill for a total of approximately 63 stream miles. Apparently unaffected by moderate organic enrichment, siltation from mica mining wastes (11), phosphate tailing waste (turbidity and siltation).

Dubiraphia - Found below sewage treatment plants in the recovery zone. The Academy of Natural Sciences of Philadelphia (1) found this genus above chloride wastes In the north Fork of the Holston River, but absent as far down stream as mile 9.2, where chlorides may run over 800 mg/L. This elmid reappeared in 1962 at mile 4.6 where a varied elmid fauna existed.

Promoresia - Very sensitive to Kraft paper mill and viscose rayon wastes.

Optioservus - Common in recovery zone of stream receiving treated sewage. Also found on the North Fork of the Holston River where chlorides are high (over 800 mg/L).

Stenelmis sexlineata - Resistant to moderate sewage pollution and phosphate tailing wastes. A ubiquitous species on the Duck River, which has in times past been seriously polluted in certain areas by untreated sewage and effluents from elemental plants. Possibly the most resistant species found in Tennessee.

Stenelmis creanta - A species much more sensitive than the above to sewage and phosphate wastes. Resistant to high chlorides.

Stenelmis decorata - Resistant to sewage and phosphate tailing wastes.

The members of this family should prove of value in the study of stream pollution in Tennessee. A closer examination of the water quality requirements of each species, would enable one to draw a clearer concept of stream conditions as related to other benthic invertebrates. The lack of biological data from many English rivers which Dr. Hynes decries (5) is also missing for many rivers in the United States, Had we known the faunal (including Elmid) composition of certain steams prior to pollution the effectiveness of biological studies would be heightened. As conditions stand now these beetles may be used as parameters of water quality in tracing the re- appearance of certain faunal groups as stream conditions improve.

16ATER QUALITY REQUIREMENTS pH

Streams having a low pH were not checked for an elmid fauna, however, the Duck River which has a varied fauna, consistently runs high in pH values during the sum- mer months. The middle and lower sections average over 8.0 and often are as high. as INDIANA ILLINOI Ohio R. WEST VIRGINIA

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C13: 1q_,00lfsahatchie \ * GEO A QZ) 1 E. Mississippi t RESERVOIRS F. Tennessee tr a. Kentucky * \ G. Duck MISSISSIPPI o b. Pickwick 'N., % H. Cumberland cif' . e. Watts Bar I. Holston -, EAST I GULF COASTAL WLAIN U. Cherokee J. N. Fork Holston . Nf 0 e. Norris K. Nolichucky ALABAMA ,.::7' PHYSTOGRAPHIC PROVINCES of TENNESSEE

and SURROUNDING STATES ■

8.9. Common species found in this section of the Duck River are Macronychus glabratus, Stenelmis lateralis, S. sexlineata, S. beameri, S. decorate, S. crenate, Ancyronyx variegatus, and Microcylloepus pusillus.

D.O.

The dissolved oxygen requirements for F]mid beetles are critical since the larvae and adults both are dependent upon this source for respiration. Unlike many other water beetles, Elmid adults do not have to surface for renewal of air supply.

The larvae have three retractile tufts of filamentous gills in the terminal abdominal segments. Adults are able to remain submerged indefinitely due to the hydrofuge system (these are silvery patches of tomentum) collecting bubbles of oxygen which are passed to the spiracles for respiration or stored beneath the elytra (12), therefore, Elmid beetles are excluded from septic reaches of a stream. Some species can adapt in areas of low dissolved oxygen.

Dubiraphia larvae are possibly better adapted to lakes and slow moving rivers, due to the much elongated caudal filaments and gill chamber (6) The following are some observed D.O. values correlated with Elmid distribution:

Table 1*

Harpeth River, Franklin, Tennessee (Receives treated sewage and chicken-processing wastes)

Station Number 1 4 7 10 Location Above Below STP U.S. Hwy. 431 Above Mouth Pollution Outfall and At Walkers Bend of West Bypass Harpeth River

Stream Mile 91.9 79.1 74.2 70.9 avg. max. & min. D.O. 6.2-6.9-5.7 300-501-1.4 4.6-5.544.0

Stenelmis sexlineata Common ----- abundant

Dubiraphia vittata Abundant rare

Stenelmis beameri rare common

*Samples collected Sept. 9-13, 1963 during the critical low flow season.

Chlorides (as Cl )

Studies on the North Fork of the Holston River, which runs high in chlorides due to the effluent of a soda ash plant,' reveal some remarkable tolerances to chlorides by several species of Plmids. -12 -

Table 2

North Fork of the Holston River

*Mendota, Va. *Weber City, Va. Kingsport, Tenn.

River mile (app.) 4o 9.2 4.6

Chlorides (Cl)-) avg. ppm , 00 825

Stenelmis crenata X

Stenelmis bicarinata X

Optioservus fastiditus X atioservus ovalis X

Optioservus sp. X

Dubiraphia sp. X

Microcylloepus pusillus X

Macronychus glabratus X

* SP ref. no. 1

Particulate Matter

The turbid sand-bottomed streams of west Tennessee support populations mainly of Ancyronyx variegatus and Macronvchus glabratus, although occasionaly Stenelmis or Dubiraphia may be represented. Wastes from phosphate ore processing plants which produce elemental Phosphorus have been shown to severly suppress the normal Elmid fauna of the Duck River with the exception of Stenelmis sexlineata. Besides producing turbidity and siltation, the toxicant, elemental phosphorus, has reached the river. Mica mining wastes entering the Nolichucky River have apparently had little effect upon at least two species, Gonielmie dietrichi and Microcylloepus pusillus. Siltation in this river has been so severe in recent times that mica has been profitably dredged from the deposited material in Davy Crockett Reservoir (lo- cated on the mid-river reach of the Nolichucky in Tennessee).

Pre-impoundment Records on tha Upper Tennessee River and Holston River.

Fortunately several reservoir areas in East Tennessee were sampled for the biota prior to impoundment. The following table has been extracted from the data contained in papers of Lyman and Deady (3, 9, 10): - 13 -

Table 3

Mesosaprobic Oligosaprobic Petersen Surber Surber Surber Surber Above M. Clinch R. 109.9 104.3 65.1

Reservoir Area Watts Bar Cherokee

Station Number 1 II II III V

Microcylloepus pusillus R R C R

Stenelmis crenata R R

Stenelmis mera R R .e,L

Stenelmis sp. R C R R C

Dubiraphia quadrinotata R R R

Ancyronyx variegatus C

NH3 (Dissolved Ammonia) pm 0.152 6.60

The Elmid fauna which Dendy and Lyman. (10) found on the Holston River in 1941 is quite similar to that found by Tennessee Stream Pollution Control Board biologists in 1962 on the lower North Holston River. Riffle beetles were not taken in samples from the upper Holston River at Churchill, just below the mouth of the South Fork of the Hoistor River. Below Cherokee Reservoir, and above the mouth of Flat Creek at Mascot, riffle beetles were once again common. Unfortunately the sample containing these was not examined, so specific records are lacking.

R - rare C - common - 14 - REFERENCES

(1). Academy of Natural Sciences of Philadelphia. 1955. North Fork of the Holston River, Virginia, Stream Survey Report. 98 pp. (effects of soda- ash waste on the biota).

(2). Burke, Horace B. 1963. Notes on Texas Riffle Beetles (Coleoptera, Elmidae). The Southwestern Naturalist 8 (2): 111-114.

(3). Dandy, Jack S. 19144. Notes on Trichoptera, Elmidae, and Plecoptera from Pre-impoundment Bottom-fauna Studies of Cherokee and Watts Bar Areas (Ten- nessee). Jour. Tenn. Academy of Science. 19:175-176.

(4). Gaufin, Arden H. 1957. The Use and Value of Aquatic Insects as Indicators of Organic Enrichment. Biological Problems in Water Pollution United States Public Health Service pp. 136-149.

(5)0 Hynes, H. B. N. 1961, The Biological Assessment of River Pollution. The River Board's Association Annual Conference, Brighton 1961, Reprint 8 pp.

(6). Leech, Hugh B. and H. P. Chandler, 1956. Aquatic Coleoptera, Chapter 13 p. 293-371 in, Aquatic Insects of California edited by Robert L, Usinger. Univ. of California Press. (Excellent keys and line drawings for separation of all Nearctic Elmid genera).

(7). Leech, Hugh B. and Milton W. Sanderson. 1959. Coleoptera. Chapter 38 p. 981- 1023 in Fresh-Water Biology (Second Ed.) edited by W. T. Edmondson, Wiley, (Excellent keys and line drawings, essentially the same keys as ref. no. 13.

(8). Lbding, Henry Peter. 1945. Catalo5ue of the Beetles of Alabama Monograph 11 Geological Survey of Alabama. 172 pp.

(9)0 Lyman, F. Earle. 1943. A Pre-iMpoundment Bottom-fauna Study of Watts Bar Reservoir (Tennessee). Trans. American Fisheries Soc 72:52-62.

(10). Lyman, F. Earle and Jack S. Dendy. 1943. A Pre-impoundment Bottom-fauna Study of Cherokee Reservoir Area (Tennessee). Trans. American Fisheries Soc. 73: 194-208.

(11). MUllican, Harold N.; Ralph M. Sinclair; and Billy G. Isom. 1960. Aquatic Biota of the Nolichucky River in Tennessee. Tennessee Stream Pollution Control Board Nashville, Tennessee (effects of mica mining wastes and viscose rayon wastes).

(12). Sanderson, Milton W. 1938, A Monographic Revision of the North American Species of Stenelmis (Dryopidae: Coleoptera). The Univ. of Kansas Science Bull. 25 (22): 635:717.

(13). Sanderson, Milton W. 1953-1954. A revision of the Neactic Genera of Elmidae (Coleoptera). Journal of the Kansas Entomological Soc. 26(4):148-163; 27(1) 1-13.

(14). Snow, W. E.; Eugene Pickard and J. B. Moore, 1958. Observations on Blackflies (Simuliidae) in the Tennessee River Basin. Journ. Tenn. Academy of Science. 33(1):5-23. (also contains observations on the Elma3-7.

(15). Young, Frank N. 1954. The Water Beetles of Florida. Univ. of Florida Studies, Biological Science Series. 5(1):1-238.

(16). Young, Frank. N. 1961. Effects of Pollution on Natural Association of Water Beetles. Purdue Univ. Engineering Bull. Engineering Series No. 106, 15(2):373- 380, Acknowledgement

I am grateful to the late Dr. Willis E. Snow, TVA biologist. Dr. Snow made an extensive study of the mosquitoes of the Tennessee Valley, the reports of which were pub- lished mainly in the Journal of the Tennessee Academy of Science. His untimely death rune 12, 19597 prevented his making a more complete report on the Elmidae, in which he had considerable interest.