Redescription Of Nerthra Praecipua (Heteroptera: Gelastocoridae) From Chile

4 Pages·1998·1.2 MB·English

by  J T Polhemus

Vol. 109,No. 1,January&February, 1998 33
REDESCRIPTION OF NERTHRA PRAEC1PUA
(HETEROPTERA: GELASTOCORIDAE)
FROM CHILE
1
J.T.Polhemus2,T.CekalovicK.3
ABSTRACT: Nerthrapraecipua,knownpreviously fromtheholotypefemale,hasbeenredis-
coveredinChile. Thespeciesisredescribed,supplementingtheincompleteoriginaldescription
ofthedamagedfemaleholotype. This speciesbelongs totheNerthraalalicollisgroup, which
occursinAustraliaandChile.
Nerthrapraecipua Todd was described byTodd (1957) from a unique fe-
male in the Reed Collection (acquired by C. J. Drake, now housed in the Na-
tional Museum of Natural History, Washington, D. C.) that had been badly
A
damagedbydermestids,renderingacompletedescriptionimpossible. single
additional female has been collected by the junior author on Chiloe Island,
Chile, providing the firstdefinitive locality andpermittingfurtherdescription
ofthe species. It is held in the J. T. Polhemus Collection (JTPC).
Nerthrapraecipua Todd
NerthrapraecipuaTodd, 1957:151,Fig. 9(Holotype,female,Chile,ReedCollection,now
inUSNM);Todd, 1961:472(checklist).
SupplementaldescriptiontothatofTodd(1957).
Female: Length8.10mm; widthofpronotum5.50mm; widthofabdomen6.02mm.
Generalcolorstramineous,withscattereddarkmarkingsonveinsofhemelytra,head,me-
dian lobe ofpronotum, scutellum; depressions on head, median lobe ofpronotum, fuscous to
piceous;anterior2/3oflateralmarginsofabdominaltergitesIII-VIdark;scutellumwithlateral
tumescencefuscous,anterolateralanglespiceous. Thoracicventermostlystramineous, mesos-
ternum medially mostly piceous except median anterior margin and medial protuberance; ab-
dominal venter mostly dark, with scattered yellowish markings, laterally and distally lighter.
Legsstramineous,withfuscousmarkings;forefemorabroadlyinfuscated,withfasciaatdistal21
3;middleandhindfemorawithfasciaatbasal 1/3,irregularannulusatdistal2/3,distalextreme,
fuscous; tibiadarkdistally.
Structuralcharacters: Headexcavateanteriorly,withoutapicaltuberclebutwithsmallapi-
cal protuberance, with superapical and lateral tubercles (Fig. 4), set with clavate setae, ocelli
absent. Pronotum with median lobe raised, sculptured, set with scattered short clavate setae.
Abdominal tergitessinuate,extendinglaterallybeyondhemelytra(seeTodd, 1957, fig. 9),with
groupsofmoderate-lengthclavatesetaeonposterolateralangles. Hemelytrawithoutmembrane,
partially fused, with thin medial lineofdemarcation between hemelytra, set with shortclavate
setaealonglateralmargins;networkofveinsmoreextensivethandepictedbyTodd(loc.cit.).
1 ReceivedMarch 15, 1997. Accepted May 15, 1997.
2ColoradoEntomological Museum,3115 S.YorkSt.,Englewood,CO. 80110.
3Casilla764,Concepcion,CHILE.
ENT.NEWS 109(1): 33-36,January&February, 1998
34 ENTOMOLOGICALNEWS
Fore femurwith edge ofanteriordilation forming about a 50 angle with posterioredge;
anteriortrochanterwithtwoblack-tippeddenticles(Fig. 5).
Abdominal stemites almost symmetrical (Fig. 2); ovipositor lobes slightly asymmetrical,
locatedposterodorsally(Figs. 1,3).
Figures 1 - 5. NerthrapraecipuaTodd, female, (scale bar - 1.0 mm). 1 - 3. Abdominal
terniinalia. 1. dorsal view. 2. ventral view. 3. lateral view. 4. Head, dorsal view. 5.Anterior
trochanter,withblack-tippeddenticlesanteriorly.
Materialexamined. 1 female,Chile,ChiloeIsland,PuentelaCaldera,41 40'S,74 02'W,
15Feb. 1996,T.CekalovicK.(JTPC).
Comparative notes. TV. praecipua does not resemble any other South
Americanspecies,andistheonlyAmericanmemberoftheN.alaticollisgroup.
It is the only American species with sternite VII prolonged posteriorly and
lacking emargination, with the female genital structures located dorsally. In
Todd's (1960) key to Australian species of Nerthra, N. praecipua drops at
couplet3becauseitlacksocelli;thus,inthisregard,itisuniqueinthealaticollis
group. Todd (loc. cit.) stated that speciesofthe alaticollisgrouphave an api-
cal tubercle, but in N. adspersa (Stal) andTV. stall (Montandon) it is no more
than a small apical protuberance, similarto thatofN.praecipua.
Habitat. The habitat in which the single specimen was collected is sur-
rounded on all sidesby forest, situated inhills ofmoderate altitude. The veg-
etation is native and semihumid. The trunks and limbs of trees in various
states of decay are covered with mosses, lichens, and adhering ferns of the
genus Hymenophyllum. The vegetative community is a typical damp
Nothofagus forest.
The specimen was separated from asample ofhumus (TC-427) by means
Vol. 109,No. 1,January&February, 1998 35
ofa Berlese funnel, in company with various arachnids and insects including
Peloridiidae (Coleorrhyncha: Peloridora sp.).
Zoogeography. N. praecipua provides another link between the hemi-
pteranfaunasofAustralSouthAmericaandAustralia. ConcerningN.praecipua,
Todd (1957) stated that"The projecting median portion ofthe last abdominal
sternite and general appearance would seem to indicate that this species is
mostclosely relatedtothe speciesofthealaticollisgroup found inAustralia."
Thisisaninterestingobservation(supportedby independentinvestigationsby
JTP) because Chile and adjacent austral Argentina are Gondwanan in origin,
and several diverse groups found there are phylogenetically linked to New
Zealand,Australia,andNewGuinea(e.g. mayflies,Edmunds, 1975;Aradidae,
Isoderminae,Monteith, 1982:649;Peloridiidae,Evans, 1981;Nothofagus,Ash,
1982:355).
TheprojectingabdominalsterniteVIIoffemalesanddorsal locationofthe
female genital structures is a synapomorphy for the clade comprising the
Nerthraalaticollis,laticollis,elongata,andrugosagroupsestablishedbyTodd
(1955, 1960). The laticollisgroupoccurs inAustralia and Melanesia (mainly
Solomon Islands and New Guinea), the elongata and alaticollis groups occur
on Australia, but the latter also on Chile. The rugosa group has only a few
species that occuron various islands and continental land masses, and appar-
ently all are halophilous and are rarely ifeverfound far from the seashore.
The associated Peloridiidae, a hemipteroid family of almost exclusively
flightless bugs (only one species with rare macropters), is ofinterest because
of its association with, and zoogeographical parallels to, flightless Nerthra
species. The primary ecological difference between them is that peloridiids
are primarily cool-adapted moss inhabitants not yet found on New Guinea,
whereas the flightlessNerthra are mostly warm-adapted litter inhabitants that
are absent from New Zealand. Evans (1981:395) speculated that peloridiids
will be found in theNothofagus forests ofNew Guinea.
ACKNOWLEDGMENTS
Wethank D.A. PolhemusandR.T.Schuh fortheirconstructivereviews. Support forthis
research was provided in part by grant BSR-9020442 from the National Science Foundation,
Washington,D.C. ThisresearchwascarriedoutasanadjunctfacultymemberofColoradoState
University.Wethanktheseorganizationsfortheircontinuedsupportofresearchintothesystem-
aticsandzoogeographyofaquatic Heteroptera.
LITERATURECITED
Ash,J. 1982. TheNothofagusBlume(Fagaceae)ofNewGuinea,pp.355-380In: Gressitt,J.L.
ed.,BiogeographyandEcologyofNewGuinea,Junk,TheHague.
Edmunds,G.F.,Jr. 1975. Phylogenetic biogeographyofmayflies. Ann. Missouri Bot.Gard.
62:251-263.
36 ENTOMOLOGICALNEWS
Evans, J. W. 1981. A review ofthe present knowledge ofthe family Peloridiidae and new
generaandnew speciesfromNewZealandandNewCaledonia(Hemiptera: Insecta). Rec.
Austr. Mus. 34:381-406.
Monteith,G.B. 1982. BiogeographyoftheNewGuineaAradidae(Heteroptera),pp.645-657
In: Gressitt,J. L.ed.,BiogeographyandEcologyofNewGuinea,Junk,TheHague.
Todd,E.L. 1955. AtaxonomicrevisionofthefamilyGelastocoridae(Hemiptera). Univ.Kans.
Sci. Bull. 37:277-475.
Todd,E.L. 1957. FivenewspeciesofGelastocoridaewithcommentsonotherspecies(Hemi-
ptera). Proc.Entomol.Soc.Wash. 59:145-162.
Todd,E.L. 1960. TheGelastocoridaeofAustralia(Hemiptera). Pac. Insects2:171-194.
Todd, E. L. 1961. AchecklistoftheGelastocoridae (Hemiptera). Proc. Haw. Entomol. Soc.
17:461-476.
SCIENTIFIC NOTE
AN UNUSUAL OCCURRENCE OF CADDISFLIES
(TRICHOPTERA: PHRYGANEIDAE) IN A
PENNSYLVANIA POPULATION OF THE PURPLE
PITCHER PLANT, SARRACENIA PURPUREA
R.HamiltonIV2,R.L.Petersen2,R.M.Duffield2'3
Whilestudyingthecontentsofonehundredandfourleavescollectedfromapopulationof
purplepitcherplantsinChristnerBog,SomersetCounty,Pennsylvania,onMarch 13, 17,and22,
1996,fivecaddisflylarvaewererecovered. Threelarvaewerealiveintheircases,onelarvawas
deadinacase,andonewasdeadandcoveredbyafungusidentifiedasaspeciesofSaprolegnia
(Saprolegniaceae)(Coker, 1923). ThelarvaewereidentifiedasbelongingtothegenusOligostomis
(Phryganeidae). Adult caddisflies collected in the same site in May 1996, were identified as
Oligostomisocelligea(Walker). ThisisthefirstreportofOligostomislarvaeinpitcherplants.
The presence ofthiscaddisfly isprobably relatedtothe floodingofthehabitatduring the late
winterandearlyspring.
Purplepitcherplantsarecarnivorousplants,usuallyfoundinnitrogen-deficient,Sphagnum-
dominatedbogsorswamps. Awidevarietyofspeciesofinsectsandotherarthropodsareasso-
ciatedwiththepitcherplant. These invertebratescanbeclassifiedasregularinhabitants,prey,
occasional associates, orplant herbivores (Rymal and Folkerts, 1982). Caddisfly larvae have
beenreportedinpitcherplants (Browerand Brower, 1971; Cresswell, 1991),yetitisnotclear
whattheirpresencesignified.
The waterlevel in wetlandscan rise significantly aftersnow meltorrain, submergingthe
pitcherplant leaves. Thiswouldpermitaquaticorganismstomoveinsideand/orontopofthe
leaves. Pittmanetal. (1996)proposedthataquaticpredatorsmaygainentrance tothepitchers
during periods ofhigh water and flooding, and feed on the inhabitants. While it is possible
caddislarvaemayhaveinadvertentlyenteredthepitcherplantleavesduetoflooding,wesuggest
thatthelarvaerecoveredinthisstudyenteredthepitcherplantleavesinsearchoffood. Oligostomis
(Continuedonpage50)
1ReceivedApril28, 1997. AcceptedJuly28, 1997.
2DepartmentofBiology,HowardUniversity,Washington,D.C. 20059.
3Towhomcorrespondenceshouldbesent.