A NEW SPECIES OF GNATHOXYS (COLEOPTERA CARABIDAE CARABINAE) FROM AN URBAN BUSHLAND REMNANT IN WESTERN AUSTRALIA

2007·2 MB·English

by  A Nadine Guthrie

Recordsofthe WesternAustralian Museum23: 213-217(2007).
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A new species of Gnathoxys (Coleoptera: Carabidae: Carabinae)
from an urban bushland remnant in Western Australia
NadineA. Guthrie
DepartmentofEnvironmentandConservation,WildlifeResearchCentre,
POBox51,Wanneroo,WesternAustralia6946,Australia
Email: [email protected]
Abstract- Gnathoxyspannuceussp. nov. is described and illustrated froma
specimen collected from Woodman Point Reserve, Western Australia. It is
distinguished from other Gnathoxys species by the highly distinctive
wrinkled pattern on the elytral surface, a feature that immediately
distinguishesitfromallothermembersofthegenus.
INTRODUCTION Ball 1998). Within Australia, the group is an
The ground beetle genus Gnathoxys Westwood important element in the beetle fauna ofarid areas
1842 is endemic to Australia and 16 species are (Matthews 1980). There are 11 recognised
currently recognised. The majority of these species Australian genera, with all species endemic, but
occur in the southwestern region of Western twogeneraarerepresentedbyotherspeciesoutside
Australia and seven occur along the Murray- ofAustralia (Mooreet. al. 1987).
DarlingRiversystem (Mooreetal.1987). Gnathoxys A recent survey of urban bushland remnants in
punctipennis Macleay 1873, also occurs along the Perth, WesternAustraliasurveyedanumberofsites
southern coastal regions between southwest in the metropolitan area and a large number of
Western Australia into the South Australian Gulf carabid specimens, including several species of
region. Twospecies havenotbeen seensince initial Gnathoxys, were collected in pitfall traps (How et.
collection: G. irregularis Westwood 1842, reported al. 1996;Guthrie2001).Amongstthesesampleswas
from Port Essington in the Northern Territory by asinglerepresentativeofanunusualnewspeciesof
Westwood (1842) and G. sulcicolhs Sloane 1910, GnathoxyscollectedfromWoodmanPoint,southof
from central Australia (no type locality was Perth. The distinctive appearance of the elytra!
reported forthisspecies; Mooreetal. 1987). sculpturing ofthisspecimen is sufficienttosuggest
Since initial collection, little has been determined thatthisrepresentsanewspecies,andthespeciesis
about the ecology, taxonomic relationships or namedanddescribedinthispaper.
distributions of the various species within
Gnathoxys. Generic relationships are not clear;
MATERIALSANDMETHODS
however, Macleay (1864) suggested tentative
associations between C. tesselatus Macleay 1864 The specimen was collected using wet pitfall
and Promecoderus based upon the dilation of the trapsalonga 100metretransectsetwithanethylene
male fore tarsus. Roig-Juhent (2000) however, glycol mix (400 ml of 70% ethylene glycol, 30%
determined that within the Broscitae, Gnathoxys water). The specimen was stored in 75% ethyl
forms a natural groupingwith theotherAustralian alcohol until identification and removal of the
endemic genera Cerotalis, Adotela and genitalia, and then pinned. The specimen is lodged
Brithysternuin and isonly distantlyrelated toother intheWesternAustralianMuseum,Perth(WAM).
genera (including Promecoderus, Creobius and Measurements were taken using a stereo
Cascellius) within the subtribe Creobiina of the microscope with vernier callipers and expressed in
Broscitae. Gnathoxys is unique among this group millimetres. Body length was measured from the
and is defined by possessing fore tibia with two apicalmarginofthelabrumtotheapexoftheelytra
medial teeth, fore and middle tibia markedly (T-L). Length of pronotum was taken along the
palmate, and maxillary and labial palpal apical midline (P-L). Foretibia length wasmeasured from
segmentsofmalessecuriform (Roig-Juhent2000). thefemurjointtotipof1“tibialtooth(FT-L).
The broscitines are diverse and medium sized The gross genital morphology was examined by
ground-dwelling beetles distributed in temperate, relaxing the specimen in a mixture of soapy
subarcticandsubantarcticregionsoftheworld,and distilled water and 2% acetic acid. The genitalia
aregenerallyabsentfrom thetropics(Davidsonand were then dissected out and cleared overnight in
214 N.A.Guthrie
cold 10% potassium hydroxide. Once cleared, the collectedbyJ. M.Waldockand M.S. Harvey (WAM
pH of dissected parts was neutralised in dilute #38293).
acetic acid. The dissected male genitalia were
placedinglycerineforexamination (Liebherr1990). Diagnosis
Gnathoxys pannuceus is similar in overall
SYSTEMATICS appearance and size to G. crassipes Sloane but is
distinguished from all other Gnathoxys species by
being heavy in appearance with a large head
FamilyCarabidae
relative to overall size. The pronotum is strongly
SubfamilyCarabinae globularinshape with a distinct medial sulcus and
faint wrinkles on the otherwise smooth dorsal
TribeBroscitae surface.Thepronotum andelytramarginshavefine
longsetaeingreaterabundancethanothersimilarly
Genus GnathoxysWestwood,1842 sized Gnathoxys. The most obvious character that
Typespecies separatesthisspeciesfromall othersinthegenusis
None designated by Westwood, but originally the striking elytral pattern. Whereas G. granularis
included nominotypical species; Gnathoxys has distinct granulated areas on the elytra, and
granulans Westwood, 1842; Gnathoxys irregularis other Gnathoxys species possess elytral patterns
Westwood, 1842. GnathoxysgranularisWestwood, consisting of foveae, punctures or similar
1842 by subsequent designation of Roig-Juhent depressions, this species has a highly distinctive
2000 wrinkledpattern.
( ).
Description
Gnathoxyspannuceus,sp.nov.
Figures 1-7 Male(holoti/pe) (Figures1,2)
Total length= 13.3mm;elytrallength/width=7.6/
Material examined 5.9 mm; pronotum length/width=4.3/5.1 mm;head
length=3.0 mm; fore tibia length=2.9 mm. Colour
Holotype entirely black without bronze or olive sheen, with
Male, Woodman Point Reserve, Western darkorangeeyes.
Australia, site WP2 [32°07'50"S 115°45'28"E], wet
pitfall trap, 4 November 1994-19 January 1995,
Figure1 Dorsal habitus of Gnathoxys pannuceus
mm
holotype;maletotallength13.3
Anewspeciesof Gnathoxys 215
Head.Verylong,heavymandiblesapproximately
2/3ofheadlength,slightlycurveddownward.Inner
mandible edge straight and toothless, curved
toward apexwith deep overlap otmandible apices.
Mandibular groove wide and shallow,
approximately half mandible length, mandibular
ridge very narrow. Single seta at groove apex and
non-setiferous puncture on outer curve of
mandibles near apex. Single seta on medial surface
of 2""' segment of palp and on ventral surface of
basal segment of maxilla palp. Maxillae and labial
apicalpalp segments securiform. Two finesetae on
anterior mentum medial margin and one on either
sideofextremitiesofbasal maxilla. Labrumslightly
broader than long, bifid and rounded. Medial
sulcus extremely faint. A fringe of setae on under
side of labial anterior margin and three pairs of
setaeonlabialdorsalanteriormargin.Outerlabrum Figure3 Gnathoxys pannuceus sp. nov. Detail of
edges yellow with remainder reddish brown. Eyes apical elytral surface showing extremely
round, convex and not prominent or overly large. irregularsulci.
Antennashort,moniliformwithsinglesetaonscape
and segments 4-11 covered dorsally and ventrally
withthickshortsetae.Supraorbital setaposteriorto punctate seta. Femur with one cluster of setae on
eye, with supraorbital sulcus running forward, anteriorventraledge,twosetaeonposteriorventral
terminated posterior to mandibular ridge. Deep edge, three setae on centre ofposterior dorsal edge
latero-medialsulcusoneithersideofhead, initiated anda clustercentrallypositioned ondorsal surface.
in line with anterior half of eye, extended directly Two teeth presenton outer fore tibial edge, medial
forward to lateral extremities of clypeus. Clypeus one smaller, both with a seta positioned on
medially and anteriorly depressed, with one mid posteriordistalmargin.Lineararrangementofthree
andtwolateralcreasesmediallyaligned. setae along midline in line with antennal cleaning
Prothorax.Pronotumveryrounded,sub-spherical organ. A row offinesetae along inneredge oftibia
with very weak extensions at cervTcal collar terminated at cleaning organ. Rounded, flattened
insertion point. Narrow pronotal marginwithsetae apicaltoothdirecteddistally.Tarsomerestriangular
in anterior and posterior third of margin. Medial with outerlateraledgeextended,narrowed distally
sulcusextended forwardtoanteriormargin.Lateral towards2"'^ tarsomere.Tlrreeorfourstiffened setae
wrinkles traverse pronotum surface, strongestnear onboth tarsomere edges. Apical tarsomere filiform
medial sulcus, lateral margins and towards with 2 setae on lateral edges, tipped with
thickenedandbluntbasal margin. Prosternum with symmetricalshortcurvedclaws.
wrinkles around sparse cluster of setae in front of Midleg; Coxae with a cluster of setae on anterior
eachleg(widestanteriorly), wrinklescontinueonto surface, one seta on ventral surface, and one
proepimeron, tubercles reduced to slight swollen ventrallyontrochanter.Clustersofsetaepresenton
areasbetweenanteriorcoxa. anterior, dorsal and posterior femoral surfaces.
Pterothorax. Elytra are sub-quadrate, slightly Femur widened dorso-ventrally. Tibia with linear
longer than broad with rounded sides and apex. rows of stiff setae orientated distally on anterior
Peduncle thick and short with heavy shoulders and posterior surfaces. A triangular apical tooth
projecting. Elytral marginvery thin, with fivesetae with stiffened setae fonning a fringe around distal
evenly spaced along anterior two thirds ofmargin. surfaceoftibiaattarsusinsertionpoint.Twosimilar
Apical declivity finely granulated, extending over sized apical teeth inserted below tarsus. Tarsal
posterioronesixthofelytra.Granulationsextending arrangementidenticaltoforetarsus.
along lateral margins, diminished anteriorly. Four Flindleg:Coxaewithtwosetaeonapicalandbasal
setae evenly spaced along dorsal edge of apical margins. Cluster of setae on posterior and dorsal
declivity on each elytron. Dorsal surface of elytra surfaces of trochanter. Long setae in curved linear
finely creased and wrinkled with extremely clusterson posteriorand ventral surfaces offemur.
irregular sulci, reminiscent of "crumpled Long setae sparsely distributed on distal ventral
aluminiumfoil re-flattened" (Figure3). and dorsal third offemur. Tibia elongate, flattened
Abdomen. Ventrites bipunctate medially, with with widened distal end. Rounded apical tooth on
final seta pair positioned on medial portion of tibia broad and short. Tibia edge serrated weakly,
apicalmargin. serrations with rounded points. Stiffened short
Legs.Foreleg:Trochanterventralsurfacewithone setae in linear rows thickly cover tibial surfaces.
216 N.A.Guthrie
Figures4-7 mGendaithaonxlyosbep;a6n,nluefctepuasrasmp.erneo;v.7,4,riggehntiptaalrarmienrg;e;5as,carlieghbtar(d=or1saml)mview median lobe;5b, left (ventral) view
Shortened apical teeth, equal in length set below Remarks
tarsal insertion point. Tarsal arrangement identical Gnathoxyspannuceussp.nov.wascollectedfrom
toanteriortarsus. the type locality at Woodman Point and, although
MaleGenitalia. Genital ringovoid in shape, with the pitfall traps were left open for twelve months,
slightconcavitytowardsbasal third, andthinedges only a single specimen was collected. Searches at
and no extensions (Figure 4). Median lobe (Figure the type locality during the same season over
5a,b) thick, with no curvature and a small hook at several years have failed to locate any further
apex. Orificedorsallyplaced behind apex. Left and specimens, suggesting that this species is locally
right sides of median lobe not symmetrical, with uncommon or inhabits a microhabitat that is not
left (or ventral view) extended on upper surface effectivelysampledthrough pitfalltraps.
nearorifice. Parameresdissimilar(Figures 6, 7), left Numerous unidentified forms of Gnathoxysexist
with extension on inner edge, extended to apical in collections (Western Australian Museum,
third of paramere. Right paramere larger and Agriculture W.A. and the Australian National
thicker, with thick setal brush extended from apex Insect Collection; author's unpublished
tomid-length,almostequaltoadeagusinlength. observations). Sloane (1898) listed several
Female:Unknown. unidentified Gnathoxys specimens but his
descriptions and comments are too brief to
Etymology satisfactorilyallyanyofthe descriptions with these
The specific epithet is derived from the Latin unidentified forms. Itisalsohighlylikelythatmore
adjectival pannuceus (lesser ragged, wrinkled, species of Gnathoxys will be collected in poorly
shrivelled) pertaining to the characteristic dorsal surveyed areas of southwestern Australia.
surfaceoftheelytra. Therefore, a comprehensive revision of the genus
Anewspeciesof Gnathoxys 217
incorporating all available material, including Liebherr, J.K. (1990). A new tribal placement for the
currently undescribed forms and the old types is Australasian genera Homethes and Aeolodermus
requiredimmediately. (Coleoptera; Carabidae: Odacathini). Pan-Pacific
Entomologist66(4):312-321.
MacLeay,W.J. (1864). OnthescaritidaeofNew Holland.
ACKNOWLEDGEMENTS 2"*^ paper. Transactions ofthe Entomological Society
ofNewSouth Wales!: 134-154.
I thank M.S. Harvey and J.M. Waldock for access MacLeay, W.J. (1873). Miscellanea entomologica.
to the carabid specimens collected during the Transactions of the Entomological Society of New
Ground Fauna of Urban Bushland Remnants in South Wales2:319-370.
Perth Survey. Thanks also to T. Houston, A. Szito Matthews, E.G. (1980). A guide to thegenera ofBeetles
and T. Weir for access to carabid beetle collections of South Australia. Part 1 Archostemata and
at the Western Australian Museum, Department of Adephaga. Special Educational Bulletin Series South
WA
Agriculture, and Australian National Insect AustralianMuseum,Adelaide.
Collection, Canberra. I also thank B.P. Moore for Moore,B.P., Weir,T.A. and Pyke,J.E.(1987). Rhysodidae
bringing to my attention the significance of this and Carabidae. Pp20-320. In D.W. Walton (ed).
unusual specimen. Jane McRae kindly Zoological Catalogue ot Australia. Volume 4.
photographed the holotype forme. Finally, I thank Coleoptera: Archostemata, Myxophaga and
my supervisors, Pierre Horwitz (Edith Cowan Adephaga,444pp. (Canberra:AustralianGovernment
University) and Mark Harvey for their unending PublicationService).
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tribe Broscini (Coleoptera: Carabidae): cladistic
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Manuscriptreceived29April2005;accepted10July2006