Thirteen new Dytiscidae (Coleoptera) of the genera Boongurrus Larson, Tjirtudessus Watts & Humphreys and Nirripirti Watts and Humphreys, from underground waters in Australia

2004·7.3 MB·

by  C H S Watts

TransactionsoftheRoyalSocietyofS.Aust. (2004), 128(2),99-129.
THIRTEEN NEW DYTISCIDAE (COLEOPTERA) OFTHE GENERABOONGURRUS
LARSON, TJIRTUDESSUSWATTS & HUMPHREYSAND NIRRIPIRTIWATTSAND
HUMPHREYS, FROM UNDERGROUND WATERS INAUSTRALIA.
by C. H. S. Watts* & W. F. Humphreys1
Summary
Watts, C. H. S. & Humphreys, W. F. 2004. Thirteen new Dytiscidae (Coleoptera) ofthe generaBoongurrus
Larson Tjirtudessus Watts & Humphreys and Nirripirti Watts & Humphreys, from underground waters in
Australia. Trans. R. Soc. S.Aust. 128(2), 99-129, 30 November,2004.
Thirteen new species of stygobitic Dytiscidae from inland Western Australia are described: Tjirtudessus
hillviewensissp.nov., T.microoculasp. nov., T.occidentalissp.nov., Tpadburyensissp.nov., T.wogarthaensis
sp. nov., Nirripirtiarachnoidessp. nov., N. bulbus sp. nov., N. byroensissp. nov., N. copidotibiaesp. nov., N.
dingbatensissp.nov.A'", eurypleuronsp.nov.,N. innouendyensissp.nov., andN. verrucosussp.nov.Thisbrings
thetotalofstygobiticDytiscidaedescribedfromAustraliato55,derivedfrom33discretegroundwatercalcretes
in 8 palaeodrainagcs. One species, T microocula sp. nov., has partial eyes and wings that are only slightly
reduced. Boongurrusoccidentalissp. nov. wascollectedfrombothsurfaceandundergroundwaterand is little
modified for an underground existence. Geographically the new species extend the range of stygobitic
DytiscidaeinAustraliatotheMurchisonandMooredrainagesystemsbothofwhichdraintothe IndianOcean.
Chemical andphysical characters ofthe groundwater in some ofthe calcretes in which the new species were
foundaregiven.
Ki;yWords: Coleoptera. Dytiscidae. Stygobitic. Descriptions. Newspecies. Waterchemistry.
Introduction suggesting that they are at an earlier stage of
adaptation to underground lifethan theotherspecies
This is the sixth paper in our series describing the so fardiscovered.
stygobitic Dytiscidae of Australia (Watts and Geographically the new finds extend the known
Humphreys 1999, 2000, 2001, 2003; Balke et al. distribution of stygal Dytiscidae some 300
2004). Initwedescribethenewspeciesfoundduring kilometres to the west. We also recollected sites in
fieldwork in WesternAustralia in winter2002. Four the Northern Territorythatyielded stygal Dytiscidae
new species in the Bidessine genus Tjirtudessus in 2001 without discovering any additional species.
Watts&Humphreys,and8 inthe Hydroporinegenus In addition, areas ofgroundwater calcretes nearThe
Nirripirti Watts and Humphreys, are described from Granites,TennantCreekandintheAmadeusbasinin
the westerly-draining Murchison and Moore the Northern Territory were sampled extensively
paelcodrainage systems. A new species ofthe genus without finding any Dytiscidae and only a sparse
Boongurrus Larson is described from material stygobitic fauna (Syncarids, Copepods, Amphipods)
collected mainly from interstial sand/gravels in at the occasional site. Although too early to be sure
seasonal creeks in the Pilbara but also from three the results suggest that the Australian stygobitic
bore holes accessing two different underground dytiscid fauna is restricted to inland Western
calcretes. This new Boongurrus species is fully Australian and the Ngaliabasin incentralAustralia.
sighted and winged and shows little apparent The prime aim of this series of papers is to
physical adaptation to a hyporean existence yet was formallydescribethedytiscidfaunaandtoprovidea
found together with a true stygobitic fauna in deep preliminary indication of the ground water
calcretc. characteristics in which they are found. Companion
For the first time in Australia two stygobitic papers by and with co- workers are starting to
species (only one described here due to lack of a addressquestionsofphylogenyandevolution(Balke
male specimen in one species) werediscoveredwith etal. 2003, Cooperetal. 2002, Leysetal. 2003)and
a true eye remnant, as distinct from the usual small the taxonomic composition of the rich fauna
scleriteorshortsuture line, andwingsthat, although associated with the beetles (Taiti and Humphreys
rather small, still retain veins and folded tips 2001, Karanovic and Marmonier 2002, Karanovic
2004).
' C. H. S. Watts, South Australian Museum, North Terrace, Materials and Methods
Adelaide,SouthAustralia5000.
W. F. Humphreys, Western Australian Museum, Francis Street,
Perth,WesternAustralia6000. The collection methods and measurements of
1
101) C. H. S. WATTS&W. F. HUMPHREYS
physico-chemical parameters in the water largely mesotrochanter; length 1.4- 3.6 mm....7
follow those usedpreviously (Watts and Humphreys 7 (6) - Normal ventrites 1 and 2 without suture
2000) except that the use ofa Quanta-G (Hydrolab between them (ie. number of visible
Corporation,Austin,Texas)waterqualitymonitoring abdominal segments reduced to four)
system attached to a 50 m cable permitted the (Fig. 82); length 3.2 - 3.6 mm
measurement of various physico-chemical water Tjirtudessussweetwatersensis
quality parameters (temperature, specific Watts and Humphreys
conductance (or TDS), pH, dissolved oxygen (% - Ventrites 1 and 2 with suture between
(srateudroaxt)i,onaonrdmgdepLth'),, otxhiedatliaotnt-erredfuacctiilointatpiontgenttihale t86h)e;m,leantgtlhea1s.t3i-n3i.n2nemrmportion (Figs 838-
determinationofany vertical stratification presentin 8(7) - Pronotal plicae strong, well marked,
the watercolumn in someboreholes. The instrument excavated on inside 9
was calibrated against the standards recommended Pronotal plicae weak, difficult to trace,
forthe instrument. may be absent, notexcavatedon inside .
13
Abbreviations used: 9 (8) - Mesosternum with posterior portion
WAM
BES Prefix for field numbers, triangular in midline (Figs 77, 79) 10
Biospeleology. - Mesosternum with posterior portion
SAMA SouthAustralian Museum,Adelaide. — rounded inmidline (Fig. 78) 1
WAM WesternAustralian Museum, Perth. 10(9) Prosternal process rounded at tip (Fig.
MB Groundwatermonitoring bore. 75); tip of metatrochanter pointed; lobe
on apical segmentofparamere short
Systematics Tjirtudessus morgani(Watts and
Humphreys)
Key to Australian species of stygobitic - Tip of prosternal process pointed (Fig.
Dytiscidae 76); apex of metatrochanter rounded;
- Scutellumwelldeveloped; length4.5mm lobe on apical portion ofparamere long..
1
— Copelatusabdiius Balke etal. Tjirtudessus bialveus Watts and
— Scutellum absent; length 1.0to4.9 mm..2 — Humphreys
2(1) Paramere one-segmented; metatibia 11 (9) Head broad, deflexed, metatrochanter
approximately the same width round; setae onmesofemur long
throughout; without pronotal plicae .Tjirtudessussilus Watts and Humphreys
— (Hydroporini) 34 —- With none ofabove characters 12
Paramere two-segmented; metatibia 12(11) Combined lengthoffirsttwo segmentsof
narrow at base then strongly expanding metatarsus > rest; eye remnantpresentas
towards apex; usually with pronotal small oval or triangular structure;
plicae (Bidessini) 3 paramere with long apical lobe
3 (2) —- With eyes 4 Tjirtudessuspuipa
Without eyes, may have a small (Watts and Humphreys)
chitinized plate or suture line where eyes - Combined length offirsttwosegmentsof
normally are 5 metatarsus approximately equal to rest;
4 (3) - Eyes ofnormal size; with elytral plicae.. eye remnant reduced to single short
Boongumts oecidentalis sp. nov. suture; paramerewith small apical lobe .
- Eyes approximately one-fifth normal Tjirtudessus cunyuensis
size; withoutelytral plicae — Watts and Humphreys
Tjirtudessusmicroocula sp. nov. 13(8) Elytron with row of large punctures
5 (4) - Body length approximately 1.0 mm; legs — adjacent to suture 26
stout, without swimming-hairs on fore Elytron without sutural punctures, other
and midlegs Kintingkakurutjutu — than a few weakones nearbase 14
Watts and Humphreys 14(13) Eye remnant present as a small oval or
- Body length > 1.2 mm; legs normal, all triangularstructure 23
— with swimming-hairs 6 - Eye remnant reduced to single short
6 (5) Mesofemur with spines on hind edge — suture 15
approximately the same strength as those 15(14) Mesofemur with 5 to 7 spines on hind
on mesotrochanter; length > 3.0 mm...29 edge in basal half 16
- Mesofemur with spines on hind edge - Mesofemur with 2 to 4 spines on hind
much more robust than those on edge in basal half 19
THIRTEEN NEW DYTISC1DAE(COLEOPTERA)OFTHEGENERABOONGURRUSLARSON
101
—
16(15) Protibia thick (Fig. 73); protarsus reaching mesosternum; 1.4 mm long
moderatelyexpanded,mesotarsuslessso; Tjirtudessuswilunaensis
mesotibia slightly angular Bidessodes Watts and Humphreys
gutteridgei Watts and Humphreys Pronotum moderatelyconstrictedatbase;
- Protibia thin (Fig. 74); protarsus and prosternal process not reaching
mesotarsus approximately the same size; — mesosternum; 2.3 - 3.2 mm long 24
— mesotibianotangular 17 24(23) Mesofemurwith6 spinesclosetobaseon
17(16) Length 2.5 - 2.7 mm; suture between hind edge Tjirtudessus bigbellensis
ventrites 1 and 2 complete (Fig. 83) (Watts and Humphreys)
Tjirtudessuspadburyensis sp. nov. Mesofemurwith 3 to 6 spines spread out
- Length 1.6 - 2.0 mm; suture between alongbasal halfofhind edge 25
ventrites 1 and 2 obliterated laterally 25 (24)— Suturelinebetweenventrites 1 and2well
— (Figs 84-86) 18 marked (Fig. 83); aedeagus with medial
18(17) Paramere with lobe as wide as rest of lobe parallel sided, apex not upturned
apical segment, flat on top, expanded Tjirtudessus challaensis
slightly attip Tjirtudessus masonensis — (Watts and Humphreys)
Watts and Humphreys Suture lines between ventrites 1 and 2
- Paramere with lobe shorter than rest of weak (Fig. 84),usuallyobsolete in lateral
apical segment, rounded on top, tip half; aedeaguswithmedial lobedistinctly
pointed Tjirtudessusyuinmeryensis narrower in middle, apex upturned
— Watts and Humphreys Tjirtudessusjundeeensis
19(15) Mesofemur with four spines near base; — Watts and Humphreys
antenna with segments 1 and 3 ofsimilar 26 (13) Distinct oval eye remnantpresent 27
length, segment 11 approximately 1.5x Eye remnant reduced to single short
mlemngth of segment 10; length 2.1 - 2.4 — suture 28
Tjirtudessuscueensis 27(26) Metatrochanter with tip slightly pointed
(Watts and Humphreys) (Fig. 11); sutural lines between ventrites
- Mesofemur with two to three strong 1 and 2 complete, distinct....Tjirtudessus
spines on hind edge near base; antenna hillviewensis sp. nov.
with segment 2 large, oval; segment 3 Metatrochanter with tip rounded; suture
much smaller and thinner, segment 11 between ventrites 1 and 2 obliterated
approaching 2x length of segment 10; laterally Tjirtudessus windarraensis
length 1.3 - 1.8 mm 20 — (Watts and Humphreys)
20(19)- Mesofemur with two strong spines on 28(26) Mesofemur with 3 spines on hind edge
hindedgenearbase;paramerewithapical (Fig. 28); suture between ventrites 1 and
segmentwithtwo finger-likeprojections 2complete;metatrochanterelongate(Fig.
Tjirtudessuspinnaclesensis — 29)...Tjirtudessuswogarthaensis sp. nov.
(Watts and Humphreys) Mesofemur with 5 to 6 spines on hind
- Mesofemur with three strong spines on edge; suture between ventrites 1 and 2
hindedgenearbase;paramerewithapical obliterated laterally; metatrochanter
segmentwith one finger-like projection.. rounded Tjirtudessus lapostaae
— 21 — (Watts and Humphreys)
21 (20) Mesofemur with three spines grouped 29(6) Mesofemur with spines arranged in two
togethernearbase Tjirtudessus comb-like rows along hind edge from
fridaywellensis (Watts andHumphreys) baseto apex; mesotibiathin, curved
- Mesofemurwithtwospinesnearbaseand Bidessodes limestoneensis
— one more distant 22 Watts and Humphreys
22(21) Pro and mesotibia club-shaped; antenna Mesofemur with spines on hind edge
with middle segments enlargeda little on spaced out, not dense and comb-like;
inside Tjirtudessushinkleri — mesotibia straight 30
(Watts and Humphreys) 30(29) Pro and mesotarsus with basal segment
- Pro and mesotibia elongate/triangular in much more expanded than other
shape; middle segments of antenna segments 31
virtually symmetrical Tjirtudessus Pro and mesotarsus with basal segment
— karalundiensis Watts and Humphreys only moderately expanded compared
23(14) Pronotum not constricted at base; — with othersegments 32
prosternal process reaching or almost 31(30) Antennawithsegments8to 11 noticeably
.
102 C. H. S. WATTS & W. R HUMPHREYS
thinner than others, segment 3 longer — 40
than segment 2...Tjirtudessus magnifieus 40(39) Elytron with visible ventral portion
— Watts and Humphreys extensive except close to apex (eg. Fig.
Antenna with segments 8 to 10 not — 85) 41
noticeablythinnerthan others, segment3 Elytron with visible ventral portion
same length as segment2 Tjirtudessus narrow except in basal quarter (eg. Fig.
32 (30)—mParcornoottaursmusa. lWiatttltesnaanrdroHwuemrphthraenyselytra; 41 (40) — 8L6e)ngth 3.6- 3.8 mm Nirripir4t5i
— Plernogntoht3u.m5 w-i5de.r0mtmhan elytra; length 3.233- —— sLteenggatshtos1.W5a-t2t.s5anmdmHumphreys 42
3.5mm Tjirtudessuseberhardi 42(41) Antenna with segments 6 to 8 greatly
— Watts and Humphreys expanded,much broaderthan segments 9
33(32) Metatrochanter rounded at tip; aedeagus and 10 (Fig. 42)
withcentrallobestraight, tippointed; eye Nirripirti bulbus sp. nov.
remnant small..Tjirtudessus raesideensis - Antenna with segments 6 to 10 of
— Watts and Humphreys — approximately equal size 43
Metatrochanter pointed at tip; aedeagus 43(42) Meso and metatibia elongate triangular;
with central lobe twisted, tip knobbed; body strongly boat-shaped, pronotum
without eye remnant...Tjirtudessus hahni — muchnarrower in front 44
Watts and Humphreys Meso and metatibia cylindrical (Figs 61,
—
34(2) Fromthe NorthernTerritory 35 62); front and rear of pronotum same
- From WesternAustralia 39 width (Fig. 63) Nirripirti
35(34)_ Head short, very broad, strongly — eurypleuron sp. nov.
deflexed; pronotum strongly narrowed at 44(43) Length 2.1 to 2.3 mm; metatrochanter
base; prostemal process anvil-shaped withtip sharplypointed Nirripirti
Nirripirtimacrocephalus — skaphites Watts and Humphreys sp. nov.
— Watts and Humphreys Length 1.5 to 1.9 mm; metatrochanter
Head variably shaped, not deflexed, base with tip rounded....Nirripirtikillaraensis
ofpronotum variably shaped; prosternal — Watts and Humphreys
— process "normally'1 shaped 36 45(40) Antenna with segment 2 largermamnd more
36(35) Protarsus with segment 3 not bilobed; oval than segment 1; 1.2-2.1 long
pronotumnotconstrictedatbase; antenna 52
thin, segments 1 andNi2rrsiupibretqiupaelntameres - Asnatmeensnhaapweitahssseeggmmeenntt21 mororsmealolrerl;es2s.t5h-e
— Watts and Humphreys — 3.9 mm long 46
Protarsus with segment 3 bilobed; 46(45) Mesofemurwith row ofabout 20 closely
pronotum weakly to moderately placed small spines alonghindedge(Fig.
constricted at base; antenna thick, — 43) Nirripirtibyroensis sp. nov.
segment2 much broaderthan segment 1 Mesofemur with 10 or fewer weak to
— 37 — very strong spines along hindedge 47
37 (36) Length 1.8 mm; bodywell-chitinized 47(46) Metasternalplateparallel sided (Fig. 80);
Nirripirtinapperbyensis mesofemur with 8 to 10 spines, closely
— Watts and Humphreys placed, very strong; metatrochanter long
Length 1.2 - 1.6 mm; body weakly andthin about 4 x as long as wide
chitinized 38 Nirripirtifortisspina
38 (37)— Length 1.2 mm; body only slightly — Watts and Humphreys
constricted at junction of pronotum and Metasternal plate narrowingtowards rear
elytra Nirripirti wedgeensis (eg. Fig. 81); mesofemur with 4 to 8
— Watts and Humphreys spines, weak to moderately strong;
Length 1.5 mm; body quite strongly metatrochanter moderately elongate 2 to
constricted at junction of pronotum and — 2.5 x as long as wide 48
elytra Nirripirtinewhavenensis 48(47) Metatarsus with segment 1 as long as
_ Watts and Humphreys otherscombined,with confluentgroupof
39(34) Pronotum (and head) about halfwidth of 5 strongspines in middleonoutside(Fig.
elytra(Fig. 36) Nirripirtiarachnoides 51) Nirripirticopidotibiae sp. nov.
— sp. nov. - Metatarsus with segment 1 much shorter
Pronotum>threequarterswidthofelytra than others combined, without confluent
THIRTEEN NEW DYT1SCIDAE(COLEOPTERA)OFTHEGENERABOONGURRUSLARSON 103
— group ofspines on outside 49 03' 55" S 118° 41' 58" E, 6/6/2002 W. F.
49(48) Metastemal platewithoutwings(Fig. 81) Humphreys and R Leys', SAMA; 1, 'BES 9318
Nirripirtiplutonicensis Moorarie Stnnrcalcretequarrysite419,25°52' 26S
Watts and Humphreys 117° 27' 09E, 8/6/02, W. F. Humphreys & R. Leys',
- Metastemal wings obvious but short (eg. SAMA; 2, ditto except 'BES 9320', 1 WAM 34177,
— Fig. 80) 50 1 SAMA; 1, 'BES 9246 WaggaWagga Stn, mineral
50(49) Mctafemurwith2to4small lumpson top exploration bore 28° 26' 36" S 116° 38' 9" E,
edge (Fig. 71) Nirripirti verrucosus 4/6/02, W. F. Humphreys & R. Leys', SAMA.
sp. nov.
—- Metafemurwith smooth top edge 51 Description (numberexamined, 24)
51 (50) Mesofemur with moderately strong Habitus. Length 1.9 - 2.3 mm; relatively flat,
spines; metacoxal plate nearly reaching weakly constricted at junction of pronotum/elytra;
mesocoxae Nirripirtihinzeae elongate oval; uniformly light testaceous, elytra
Watts and Humphreys uniformly darker; hindwing not reduced; eyes of
- Mesofemur with thin spines; metacoxal normal size.
plateatleastthewidthofmetafemurfrom Head. Narrower than elytra; smooth, shiny, weak
mesocoxae Nirripirtidaiiotensis reticulation towards rear, punctures small, sparse;
— Watts and Humphreys without cervical stria, subparallel in posterior half,
52(45) Elytron with shoulder flared outwards widestjustbehindeye, antennastout, segments! and
(Fig. 86) Nirripirtihamoni 2 cylindrical, segment 3 as long as segment 2,
Watts and Humphreys narrower, narrowingslightly towardsbase, segments
- Elytron with shouldernot Oared (eg. Fig. 4 to 8 becoming progressively slightly broader,
— 85) 53 segments 9 and 10 a little narrower than segment 8,
53(52) Metatrochantcrproduced into longstrong segment 11 about twice length ofsegment 10, each
point(Fig. 68) Nirripirti segment, except segment 1, with some very small
innouendyensis sp. nov. setae on inside apically. Maxillary palpus elongate,
- Metatrochanter rounded, at most bluntly segment4 as long as segments 1 to 3 combined.
— pointed 54 Pronotum. A little narrower than elytra;
54(53) Eye remnant absent; metatrochanter anteriolateral angles projecting strongly forward;
large, squat; hind leg stout; length 1.2 base weakly constricted, posterolateral angles
mm
Nirripirtimilgunensis square, surface slightly rugose, with moderately
Watts and Humphreys dense, moderately sized punctures and a row of
- Eyeremnantrepresentedbyashortsuture stronger punctures along front margin; basal plicae
at side ofhead; metatrochanter elongate; strong, excavated somewhat on inside, converging
hind leg elongate; length 1.8 - 2.0 mm.... slightly towards front, reaching to about two-thirds
Nirripirtimelroseensis wayalongpronotum.
Watts and Humphreys Elytra. Not fused, with weak inner ridges near
apex (ligula), lacking in some; elongate, nearly
Descriptions parallel-sided in middle; rugose, quite densely
covered with moderate sized punctures; plicae well
The following species descriptions are grouped in impressed, straight, aboutas long as pronotal plicae.
alphabetical order under genus which are placed in Epipleuron well differentiated from rest of elytra
the orderBoongurrus, Tjirtudessus, Nirripirti. particularly anteriorly, lacking basal carina,
relatively broad in anterior quarter then
Boongurrus Larson (Hydroporinae, Bidessini) progressively narrowingto nearapex.
Boongurrusoccidentalis sp. nov. Ventral surface. Prosternal process strongly
FIGS 13-18 narrowed between coxae, reaching mesothorax,
apical half elongate triangular, weakly arched in
Holotype lateral view with highest point (viewed ventrally)
m: '10 K NW Eerala Stn CHS Watts 23/5/01', between coxae. Mesocoxae separated. Metathorax
WAM
34222. Card mounted. strongly triangular in front in midline; wings short;
broadlyroundedin midlinebehind. Metacoxal plates
Paratypes large, quite strongly punctate, moderately rugose,
25; 8, as for holotype, SAMA; 12, 'Wittenoom metacoxal lines distinct, moderately widely spaced,
Gorge Town Pool CHS & GA Watts 26/5/01', 10 reaching to metastemum, weakly diverging; closely
SAMA,2, Lars Hendrich collection(Berlin); 1, 'BES adpresscd to ventrite 1. Ventrites 1 and 2 fused,
9277 Killara Station north, unused water bore, 26° sutural lines distinct, ventrites 3 to 5 mobile, rugose.
104 C. H. S. WATTS&W. F. HUMPHREYS
well covered with moderate sized seta-bearing Male
punctures. Little external differentiation between the sexes.
Legs. Protibia triangular, outer edge bow-shaped, Median lobe ofaedcagus broad in middle narrowing
widest towards apex where it is about fourtimes its to sharp point; paramere broad, apical segment with
basal width; protarsus weakly expanded, segment 1 relatively stout apical lobe well separated from rest
asbroadas long,segment2aswideassegment 1 and ofsegment. Figs 13-14.
abouthalfits length, segment3 as longas segment 1
and a little narrower, deeply bifid, segment 4 very Remarks
small, hidden within lobes ofsegment 3, segment 5
narrow, cylindrical, about 1.5x length ofsegment 3, This new speciesofBoongurrus closely resembles
segments 1 to 3 with dense covering of adhesive B. rivulus (Larson) from the Atherton tableland
setae; claws short and simple. Mesotrochanter region ofnorth Queensland differing externally only
elongate-oval with a few relatively long, thin setae in the larger eyes, slightly less rugose body, slightly
on inner edge; mesofemur with 4 to 5 moderately weaker tarsi and thinner antennae. The main
strong setae in basal half, only slightly strongerthan differentiating characters are the size of the eyes
those on other parts of the femur (Fig. 16), which in the new species are ofnormal epigean size
mesotarsus slightly less expanded than protarsus. in contrast to those of B. rivulus which are about
Metatrochanter tip rounded (Fig. 17); metafemur three quarters normal size and in the male genitalia.
relatively stout, lacking spines; mctatibia narrow, The aedeagus ofB. occidentalis is broader medially
moderately curved, widening towards apex; and tapers to a longer and sharper point. The apical
metatarsi relatively stout, segment 1 longest, segment ofthe paramere is longer than in B. rivulus
segment 5 longer than segment4, segments 1 and 2 and the apical lobe smaller but much more distinct
in combination about as long as others; claws weak. (Larson 1994).
Figs 1-6. Tjirtudessus hitlviewensis: 1, lateral view ofcentral lobe ofaedeagus; 2, ditto dorsal view; 3, paramere; 4,
mesotrochanter and mesofemur; 5 metatrochanter and metafemur; 6, dorsal view. Scale bar represents 1mm (habitus
only).
\
,
THIRTEENNEWDYTISCIDAE(COLEOPTERA)OFTHEGENERABOONGURRVSLARSON 105
Most ofthe specimens have been collected at the elongate, segment 4 as long as segments 1 to 3
edge ofpools in sandy riverbeds and interstitially to combined.
at least two meters from the water's edge in an Pronotum. About same width as elytra;
upstreamdirection. Ithasalsobeenrecordedasflying anterolateral angles projecting strongly forward;
to light (in Australian Insect Collection CSIRO base weakly constricted, posterolateral angles
Canberra).Alittle surprisinglya few specimenswere obtuse, overlying elytra somewhat; smooth, with
collectedduringthisyear's fieldworkfrom boreholes sparse, very weak punctures and a row of stronger
in two separate calcretes together with a true punctures along front margin; basal plicae
stygobitic fauna. The Killara North site was an open moderately impressed, converging slightly towards
unused waterbore ca 3 in to waterandawaterdepth front, reaching to about half way along pronotum;
of ca 9 m in a calcrete area and the associated numerous long setae laterally in anteriorhalf.
stygofaunaincluded Bathynellacea,crangonytoidand Elytra. Not fused, tightly closed, lacking inner
Ceinidae Amphipoda, Harpacticoida, Cyclopoida. ridges; elongate, almost parallel sided, smooth, very
The Moorarie site was a sealed monitoring bore in weakly reticulate, sparsely covered with small
calcrete within 30 m of a calcrete quarry that punctures, a few widely spaced larger punctures
penetratedthe groundwater; theboreholecontained a close to inner edge; row of long setae near lateral
stygobitic fauna comprising Bathynellacea and edge, a few additional larger punctures with long
Amphipoda. DNA studies (Remko Leys pers. com.) setae, more frequent towards sides and apex.
found differences between B. occidentalis Epipleuron moderately differentiated from rest of
specimens collected from epigean and stygal elytra, moderately broad in anterior quarter,
habitats. progressively thinnertill nearapex.
Ventral surface. Prosternal process strongly
Etymology narrowed between coxae, not reaching mesothorax,
Latin. 'Occidental' western. A reference to its apical half broad, sides slowly converging to
distribution. rounded apex, strongly arched in lateral view with
highest point (viewed ventrally) between coxae.
Tjirtudessus Watts & Humphreys Mcsocoxae in contact at midline. Metathorax
(Hydroporinac, Bidessini) broadly triangular in front in midline; wings stout,
Tjirtudessushillviewensis sp. nov. narrow; narrowly rounded in midline behind.
FIGS 1-6 Metacoxal plates large, weakly reticulate, metacoxal
lines indistinct, moderately widely spaced, reaching
H
oiotype to about halfway to metasternum, quite strongly
m. 'BES 9399, Hillview Station, bore at Camel diverging; a few small setae-bearing punctures
WHeulmlp,h2r6e°ys58'&20SR.11L7e°y2s7\' 0W9"AME, 1334/167/802., WS.lidFe. tVeonwtarridtsesmi1dlianned; 2clofsuesleyd,adspurteusrsaeld ltionesvendtirsitlienct1,.
mounted. ventrites 3 to 5 mobile, sparsely covered with small
seta-bearingpunctures, ventrites 3 and4with a long
Paratype central seta orbunch oflong setae.
1 (partial) as for holotype except ^BES 9398 Legs, Protibia bow-shaped, relatively narrow,
SAMA.
widest towards apex where it is about fourtimes its
basal width; protarsus weakly expanded, segment
1
Description (numberexamined, 1 + 1 partial) asbroadas long,segment2aswideassegment 1 and
Habitus. Length 2.35 mm; relatively flat, weakly abouthalfitslength, segment3 aslongassegment 1
constricted atjunction ofpronotum/elytra; elongate narrower, deeplybifid, segment4very small, hidden
oval; uniformly light testaceous; hindwing reduced, within lobes of segment 3, segment 5 narrow,
broad, about half length of elytron, tip slightly cylindrical about 1.5x length of segment 3,
folded; weakly sclerotized. segments 1 to3 with verydensecoveringofadhesive
Head. A little narrower than elytra; smooth, setae; claws short and simple. Mcsotrochanter
reticulation weak, punctures sparse, very small; elongate/oval with a few thin setae on inner edge;
subparallel in posterior half, widestjust behind eye mesofemurwith 4 evenly spaced spines inbasal half
remnant; eye remnant reduced to small triangular (Fig. 4) mesotarsus a little more elongate than
area. Antenna moderately stout, segments 1 and 2 protarsus. Metatrochanter tip angular (Fig. 5);
broad, oval, segment 3 as long as segment 2, metafemur relatively stout, lacking spines; metatibia
narrower, narrowing towards base, segments 4 to 10 narrow, moderately curved, widening towards apex;
subequal, segment 11 abouttwice length ofsegment metatarsus elongate, segment 1 longest, segment 5 a
10, each segment, exceptsegment 1, with somevery little longer than segment 4, segments 1 and 2 in
small setae on inside apically. Maxillary palpus, combination about as long as others; claws weak.
106 C. H. S. WATTS&W. F. HUMPHREYS
Figs 7-12. Tjirtudessus microocula: 7, lateral view ofcentral lobe ofaedeagus; 8, ditto dorsal view; 9, paramere; 10,
mesotrochanterandmesofemur; 11,metatrochanterand metafemur; 12,dorsal view. Scale barrepresents 1mm (habitus
only).
Male Tjirtudessusmicroocula sp. nov.
Female not known. Median lobe ofaedeagus with FIGS 7-12
unusually long thin apical portion, slightly
crenulated on top; paramere broad, apical segment Holotype
with long, narrow, apical lobe separated from restof m. 'BES 9223, Bunnawarra Station, bore nr.
sseeggmmeenntt.eFxicgespt1-2a.t its apex which overlaps rest of Wsh.eaFr.inHgumshpehdr,e2y8s° &36'R.35L"eySs'1,1°W3A4'M253"41E7,9.3/S6/l0i2d,e
mounted.
Etymology
Named after the pastoral station on which it was Paratypes
found. 37; 19+ 5 partial specimens, asforholotype, 8+5
partial specimens WAM 34180 - 34192, 11 SAMA;
Remarks 4, as for holotype except 'BES 9224, well near
shearers quarters, 28° 36' 36" S 116° 34' 18" E\
Most closely resembles T. windarraensis in size, WAM 34193 -34196;4,asforholotypeexcept 'BES
presence ofan eye remnant, row oflarge punctures 9225', SAMA.
on elytron adjacenttothe sutureandpointedmedian
lobeofthe aedeagus, butdiffers in the shorterapical Description (numberexamined, 38)
segment ofthe paramere and larger apical lobe, as Habitus. Length 2.2 - 2.3 mm; relatively flat,
well as having a more oval eye remnant, and a weakly constricted at junction of pronotum/elytra;
complete suture between the first and second elongate oval; uniformly light testaceous; eyes
ventrites which is obliterated laterally in T. reduced to about a fifth normal size; hindwing
windarraensis. reduced, aboutlength ofelytron,tip folded.
THIRTEEN NEWDYTISCIDAE(COLEOPTERA)OFTHEGENERABOONGURRUSLARSON 107
Figs 13-18. Boongurnisoccidentalis: 13, lateralviewofcentral lobeofaedeagus; 14,dittodorsal view; 15, paramere; 16,
mesotrochanterand mesofemur; 17 metatrochanterand metafemur; 18, dorsal view. Scalebarrepresents 1mm(habitus
only).
Head. Narrower than elytra; smooth, retieulation punctures, rowoflongsetaenearlateral edge,afew
weak, punctures sparse, small; subparallel in additional larger punctures with long setae, more
posteriorhalf, widestjustbehindeye; eyereducedto frequent towards sides. Epipleuron well
about a fifth normal size, lacking individual facets, differentiated from rest ofelytra, moderately wide
darkly pigmented. Antennarelatively thin, segments in anterior fifth, virtually absent along rest of
1 and 2 cylindrical, segment 3 as long as segment 2, elytron.
narrower, narrowingtowards base, segments 4 to 10 Ventral surface. Prosternal process strongly
subequal,segment 11 elongate,alittlelessthantwice narrowed between coxae, not reaching mesothorax,
length ofsegment 10, each segment, except segment apical half elongate triangular, sides subparallel,
1, with some very small setae on inside apically. rapidly narrowing to small blunt point posteriorly,
Maxillary palpus, elongate, segment 4 as long as strongly arched in lateral view with highest point
segments 1 to 3 combined. (viewed ventrally) between coxae. Mesocoxae in
Pronotum. A little narrower than elytra; contact at midline. Metathorax triangular in front in
anteriolateral angles projecting strongly forward; midline; wings narrow; broadly rounded in midline
base moderately constricted, posteriolateral angles behind. Metacoxal plates large, very weakly
bluntly pointed, smooth, with sparse, very weak reticulate, metacoxal lines obsolete; a few small
punctures and a few stronger punctures along front setae-bearing punctures towards midline; closely
margin;basalplicaeweak,stronglyslantinginwards, adpressed to ventrite 1. Ventrites 1 and 2 fused,
reachingtoabouthalfwayalongpronotum;withrow sutural lines distinct except in lateral fifth, ventrites
oflong setae laterally in anteriorhalf. 3 to 5 mobile, sparsely covered with small seta-
Elytra. Notfused buttightlyclosed, lacking inner bearing punctures, ventrites 3 and 4 with a long
ridges; widest behind middle, smooth, very weakly central seta orbunch oflong setae.
reticulate, sparsely covered with very small Legs. Protibia triangular, relatively narrow, widest
108 C. H. S. WATTS&W. F. HUMPHREYS
Figs 19-24. Tjirtudessuspadburyensis: 19, lateral view ofcentral lobe ofaedeagus; 20, ditto dorsal view; 21, paramere;
22, mesotrochanter and mesofemur; 23, metatrochanter and metafemur; 24, dorsal view. Scale bar represents 1mm
(habitusonly).
near apex where it is about three times its basal with long, narrow, apical lobe well separated from
width; protarsus expanded, segment 1 as broad as restofsegment. Figs 7-8.
long, segment2 as wideas segment 1 andabouthalf
its length, segment 3 as long as segment 1 much Etymology
narrower,deeplybifid, segment4verysmall, hidden Latin. 'Oculus'-eye, 'micro'-small.Areferenceto
within lobes of segment 3, segment 5 narrow, the small eyes in this species.
cylindrical, about 1.5x length of segment 3,
segments 1 to 3 with dense covering of adhesive Remarks
setae; claws moderately long, simple.
Mesotrochanter elongate/oval with a few thin setae Tjirtudessusmicroocula appears to be in an earlier
on inneredge; mesofemurwith 5 to 6 spines inbasal stage ofadaptation to an underground environment
half, basal two close together (Fig.10); mesotarsus than the other stygal Dytiscidae previously recorded
similar to protarsus. Metatrochanter weakly pointed in Australia (with the exception of Boongurrus
(Fig.11); metafemur relatively thin, lacking spines; occidentalism which is certainly not an obligate
mctatibia narrow, curved, widening towards apex; stygobiotic). The eyes are only about a fifth the size
metatarsus elongate, segment 1 longest, segment 5 ofthose in epigean members ofthegenusanddonot
longer than segment 4, segments 1 and 2 in seem tobe organised into individual ommatidia. Itis
combination about as long as others; clawsweak. hard to envisagethem as fully functional.As well as
thepresence ofpartial eyes T. microoculahas wings
Male which are still large enough to require folding and
Little external difference between sexes. Median still retain veins, the prosternal process is not
lobe ofaedeagus variable in width along shaft, tip deflexed and reaches the metathorax hence
bluntly pointed; paramere broad, apical segment separatingthe mesocoxac as in epigean species.