New Records Of Allocapnia (Plecoptera : Capniidae) From Mississippi And Louisiana, With Accompanying Scanning Electron Micrographs

6 Pages·1998·2 MB·English

by  M H Alford

Vol. 109,No.3,May&June, 1998 183
NEW RECORDS OF ALLOCAPNIA
(PLECOPTERA: CAPNIIDAE) FROM MISSISSIPPI
AND WITH ACCOMPANYING
LOUISIANA,
SCANNING ELECTRON MICROGRAPHS
1
MacH.Alford2
ABSTRACT: Seventy-onesitesweresurveyedforAllocapnia(Plecoptera: Capniidae)insouth-
westernMississippiandthreeoftheFloridaparishesofLouisiana.Thesesurveysextendedover
sixmajorriverdrainages.NewrecordsofA. virginiana,A.recta,andA.auroraarereported,and
scanningelectronmicrographsofthemalegenitaliaareprovidedforeachspecies.
Small winterstoneflies(Capniidae)constitutethe largestfamilyofPlecop-
terainNorthAmerica(Borror,Triplehorn,andJohnson 1989).Theyhavecap-
tivated curious minds at least since the mid-nineteenth century (Prison 1929)
because they are generally less than 10 mm in length and, unlike most other
insects, emerge as adults during the winter or early spring (Ross and Ricker
1971). MostcapniidsineasternNorthAmericabelongtothegenusAllocapnia
Claassen (Borror,Triplehorn, and Johnson 1989).Allocapnia is typical ofthe
Capniidaeandisdistinguishedfromtheothergeneraofthefamilyby thepres-
enceofastraightRI ofthe fore wingjustbeyond theoriginofRs(Stewartand
Harper 1996) and by the presence ofadorsal processon the eighth tergite and
adouble epiproct in males (Ross and Ricker 1971). Differentiation ofspecies
is chiefly based on characteristics ofthe male genitalia.
METHODS
Adult Allocapnia were collected from December 1996 to February 1997
by hand from bridges and by rod and beating sheet from streamside plants.
Nymphs werecollectedby browsing through leaflitterin streams. Specimens
werekilledand stored in80%ethanol andwereexaminedand identifiedusing
a dissecting microscope. The genitalia of representative male samples were
thenviewed using anAMRAY 1810D scanning electron microscope and pho-
tographed. Specimens were deposited in the entomological collection ofB. P.
Stark at Mississippi College.
Forty-eight sites were surveyed in the southwestern Mississippi counties
ofAmite,Franklin,Lincoln,Pike,Walthall,andWilkinson.Twenty-three sites
were surveyed in three of the Florida parishes of Louisiana, namely, East
Feliciana, St. Helena, and West Feliciana. The Florida parishes ofLouisiana
1 ReceivedJuly 18, 1997.AcceptedSeptember8, 1997.
2Department of Biological Sciences, Mississippi College, Clinton, MS 39058-4045. Current
address: DepartmentofBotany, DukeUniversity, Durham, NC 27708-0338.
ENT.NEWS 109(3) 183-188,May&June, 1998
184 ENTOMOLOGICALNEWS
are those thatoccurinthe southeasternpartofthe stateeastofthe Mississippi
River.ThesurveysincludedcollectionsitesfromtheAmiteRiver,BogueChitto
River, Buffalo River, and Homochitto Riverdrainages in Mississippi and the
BayouSaraandThompsonCreekdrainagesinLouisiana.Also,onesmallstream
inMississippiandtwosmall streamsinLouisianawhichflowdirectly intothe
Mississippi Riverwere surveyed (Fig. 1).
Fainga..S1i.tMesapwitohftAhlelosctaupdnyiaarerae:cosrodusthinwetshtewMiinstsiesrsoifpp1i9a9n6d-1t9h9r7eearoefitnhdeiFclaotreiddbaypaariHsheasndofneLgoautiisvie-
recordsareindicatedbyaA.Numberedcollectionsitesarefurtherdescribedinthetext.
RESULTS AND DISCUSSION
Fig. 1 isasummarymapofthesamplelocalities. SiteswithAllocapnia are
numbered as follows:
1.WilkinsonCo., MS,ClarkCr.,ClarkCr.NaturalArea,A.recta.
2.WestFelicianaP.,LA,KimballCr.atPinckneyvilleRd.,unresolved 9 (likelyA.recta).
3.WestFelicianaP.,LA, DryCr.atLA421,A.recta.
4.WestFelicianaP.,LA, MillCr.atLA421,A.recta.
5.WestFelicianaP.,LA,ThornCr.atLA421,A. recta.
6. West Feliciana P., LA, un-named tributary to Middle ForkThompson Cr. at LA 421,unre-
solved 9 (likelyA.recta).
Vol. 109,No.3,May&June, 1998 185
7.EastFelicianaP.,LA,HurricaneCr.atThompsonCr.Rd.,A.recta,A. virginiana.
8.EastFelicianaP.,LA,ShadyGroveBranchatThompsonCr.Rd.,A.recta,A.virginiana.
9.WilkinsonCo.,MS,BuffaloR.atHiramMcGrawRd.,A.recta,A.virginiana.
10.AmiteandWilkinsonCo.,MS,FosterCr.atMS33,nymph.
11.AmiteCo.,MS,FosterCr.atMS33,A.aurora,A. virginiana.
12.AmiteCo.,MS, BrushyCr.atCobbRd.,A. virginiana.
13.AmiteCo.,MS,BrushyCr.atNew HopeRd.,A. virginiana.
14.AmiteCo.,MS,un-namedtributarytoBirdman BranchatFoxRd.,A.recta.
15.AmiteCo.,MS,CastonCr.atOxford-MeadvilleRd.,A. virginiana.
16.FranklinCo.,MS, MiddletonCr.atUSFS 100,A. virginiana.
17.FranklinCo.,MS,PorterCr.atUSFS 108,A. recta,A. virginiana.
18.FranklinCo.,MS,DryCr.atUSFS 145,A.aurora,A. recta,A. virginiana.
19.FranklinCo.,MS,McGeheeCr.atlow-waterbridge,A.virginiana.
20.FranklinCo.,MS,CaneMill BranchnearLittleSprings,A.aurora,A. virginiana.
21.FranklinCo.,MS,GooberCr.atLittleSprings,A. virginiana.
22.AmiteCo.,MS,un-namedtributarytoWestForkAmiteRiver,A.recta.
Ofthe seventy-one surveyed sites, twenty-two (31%) yielded at least one
specimen of Allocapnia. The majority of these sites (82%) occur in the
Homochitto Riverdrainage ofMississippi and the Thompson Creek drainage
ofLouisiana.NospecimensofAllocapniawerecollectedfromtheBogueChitto
River drainage. Specimens were collected from one site in the Amite River
drainage, one site in the Buffalo River drainage, one site in the Bayou Sara
drainage,andone site from astream which flowsdirectly intothe Mississippi
River.
Overall, 188 adults (151Cf, 37Q) and 14 nymphs were collected. Ofthe
identifiable specimens (somedehydrated individuals were collected from spi-
der webs and some females could not be resolved), 84 (56%) belonged to
Allocapnia virginiana Prison, 62 (41%) to A. recta (Claassen) Prison, and 4
(3%)toA. auroraRicker. Scanningelectronmicrographsareprovided inFigs.
2-7.A. virginiana (Figs. 2-3) ischaracterized by a large apical segmentofthe
upperlimb oftheepiproctandby awidebut shortdorsal process with a small
anterior process. A. recta (Figs. 4-5) is characterized by a long, thin apical
segmentandadorsalprocesswithasemicircularapicalridge.A. aurora (Figs.
6-7) is characterized by a slender apical segment and a dorsal process with
widely separated lobes.
AlthoughthedataimplyapaucityofAllocapniaoutsideoftheHomochitto
River and Thompson Creek drainages, this is somewhat misleading. Two of
the three streams which flow directly into the Mississippi Riverprobably did
not produce Allocapnia individuals because occasional inundation from the
Mississippi River hinders nymphal establishment. The Bayou Sara drainage
experiences similar effects from the Mississippi River. Clark Creek, on the
other hand, has several high waterfalls in the loess bluffs region and is pro-
tected from periodic flooding and backwater.
The Buffalo River probably has more Allocapnia than reported. Of the
foursitesinvestigated,threefallwithincompanytimberland,wherethestreams
havelittercomposedprimarilyofpine straw.TheAmiteRiverandBogueChitto
186 ENTOMOLOGICALNEWS
Fig.2.Allocapniavirginianaepiproct,dorsalaspect.
Fig. 3.Allocapniavirginianaepiproct, lateralaspect.
Fig. 4.Allocapniarectaepiproct,dorsalaspect.
Fig. 5.Allocapniarectaepiproct,lateralaspect.
Fig. 6.Allocapniaauroraepiproct,dorsalaspect.
Fig. 7.Allocapniaauroraepiproct, lateral aspect.
Vol. 109,No.3,May&June, 1998 187
River,however, are somewhatdifferent. Whereas the previousdrainagescon-
sist primarily of fast-flowing, shallow, sandy streams, the Amite River and
BogueChittoRiverdrainagesconsistofdeep,slow-flowing,mixedgravel-silt
streams. The single record from theAmite Riverdrainage indicates thatAllo-
capnia are present and suggests that they are piobably limited to localized
populations where stream habitat is suitable. Further searches in the Bogue
Chitto River drainage are necessary to determine the presence or absence of
Allocapnia there.
These data indicate a wide distribution ofbothA. recta andA. virginiana.
A. recta appears to predominate in Louisiana while A. virginiana appears to
predominate in the hilly Homochitto drainage of Mississippi. This apparent
discrepancy, however, may be due to collection and emergence timing. B. P.
Stark (pers. comm.) has previously collected both species in central Missis-
sippi and A. virginiana in the Homochitto drainage. Ross and Ricker (1971)
report neither species in Louisiana or southwest Mississippi, but this may be
duetolittleornosampling inthearea.Theydo,however,reportcollectionsof
A. virginiana from eastern Mississippi and note the abundance ofA. recta in
the Coastal Plain (Ross and Ricker 1971).
Allocapnia aurora was only found in the Homochitto drainage in a few
disjunct locations. Stark (pers. comm.) has not collectedA. aurora southwest
ofTishomingo Co., MS, despite intensive collecting in central Mississippi,
and Ross and Ricker (1971) report it no farther west than southwestern Ala-
bama.This interesting anomaly ofdistribution could be the resultofdispersal
viathePlioceneTennesseeRiverenteringtheretreatingMississippiEmbayment
near southwest Mississippi during a glacial advance. Stern (1976) provides
evidenceforsuch aneventbasedonunionidmussel distributionsand sums up
the geologic evidence. Why no A. aurora occur between southwest Missis-
sippi and the southern Appalachians or southwesternAlabama, nevertheless,
remains unclear. Regardless, because distributional information is often inte-
grated with phylogeny to construct hypothetical dispersal paths and to specu-
late about selection pressures, these new records are valuable to an accurate
evolutionary understanding ofAllocapnia.
ACKNOWLEDGMENTS
Mississippi College is thanked foruse ofthe scanningelectron microscope facilities, and
Dr.BillStarkatMississippiCollegeisthankedforverifyingspeciesidentificationsandforhelp-
ful comments. Earl Alford ofthe Mississippi Forestry Commission is thanked for helping to
selectappropriatecollectionsites.
LITERATURECITED
Horror, D. J., C. A. Triplehorn, and N. F. Johnson. 1989. An Introduction to the Study of
Insects,6thed. Harcourt BraceJovanovich, FortWorth.
188 ENTOMOLOGICALNEWS
Prison,T. 1929.FallandWinterStoneflies,orPlecoptera,ofIllinois. Bull. 111. Nat. Hist. Surv.,
18:345-361,399-403.
Ross,H.H.andW.E.Ricker. 1971.TheClassification,Evolution,andDispersaloftheWinter
StoneflyGenusAllocapnia. 111. Biol. Monog.,45: 1-166.
Stern,E.M. 1976.TheFreshwaterMussels(Unionidae)oftheLakeMaurepas-Pontchartrain-
BorgneDrainageSystem,LouisianaandMississippi. Unpubl. Ph.D.Thesis, LAStateUniv.
Stewart, KW. and P. P. Harper. 1996. Plecoptera. pp. 217-266 In: Merritt, R. W. and K. W.
Cummins, eds. An Introduction to theAquatic Insects ofNorth America, 3rd ed. Kendall/
Hunt,Dubuque,IA.
BOOK REVIEW
(continuedfrompage 164)
givengeneraandspeciesisnotsotransparent(theindicesamelioratetheproblemtoaconsider-
ableextent,however). Itshouldbenotedthat theclassificationofOdonataatthe level ofsub-
families and tribes iscurrently not very well-foundedand is ina stateofflux, although this is
certainlynofaultofeitherauthor.
In general, the Steinmann volumes use amuch more traditional format, soentomologists
accustomed to using catalogs for other groups may feel more at home with them, but I have
foundthat, with a little initial effort, Bridges'catalog isextremelyeasy to use and provides a
numberofadvantages over the common approach. On the otherhand, Steinmann certainly is
physicallyeasiertouse,asitisprintedastwocompact volumes, while Bridges is aratherun-
wieldy tome. Steinmann also provides a slightly moreextensive synonymy, and the full refer-
encesappearwiththespeciestowhichtheypertain,whereasBridges'citationsarenumerically
codedandthefullreferencesappearonlyinthebibliography.Thelatterisbyfarthemoreexten-
siveandup-to-date,however,withover6500entries,anditisaccompaniedbyindicesthatallow
cross-referencingbyauthorandjournal.Thisinitselfisanoutstandinglyusefulreference.Bridges
providesno indicationofrangenordoeshe includediagnosesofany taxa, but the lastedition
doescontainanappendixwithfiguresofwingsofmostgenera.
The major failing ofSteinmann's WorldCatalog, especially compared to Bridges', how-
ever, isthat it simply is notcurrent. Ithas used Davies andTobin (1984, 1985) as its starting
point,but, although ithasaddedsubstantially totheirwork, ithasnotmovedbeyond thatas it
could and should have. Despite considerable, and accelerating, work on the taxonomy ofthe
Odonata overthe last decade, almost no species described after 1990 are included here. Also
missedwere,e.g.,Lohmann's(1992)revisionoftheCordulegastridae,andthemajorreanalysis
byCarleandLouton(1994)separatinganewfamily,theAustropetaliidae,fromthenowmono-
typic Neopetaliidae, with aradically new understanding ofthe position ofthe latter.Thus, de-
spite the 1997 publication date, this catalog lags considerably behind Bridges' 1994 edition.
Coupledwithitsastronomical price(over$850atcurrentexchangerates),thismakesithardto
recommendasapracticaltool forthestudyofOdonata,despiteitsseveral useful features.
LITERATURECITED
Bridges,C.A. 1994.CatalogueoftheFamily-group,Genus-groupandSpecies-groupNamesof
theOdonataoftheWorld(ThirdEdition). Urbana,IL,privatelypublished.
Carle,F.L. 1986.Theclassification,phylogenyandbiogeographyoftheGomphidae(Anisop-
tera).I.classification.Odonatologica 15: 275-326.
Carle, F. L., & J. A. Louton. 1994. The larva ofNeopetaliapunctata and establishment of
Austropetaliidaefam.nov.(Odonata).Proc.Ent.Soc.Wash.96: 147-155.
(concludedonpage 194)