The Hemiphlebia Damselfly 'Hemiphlebia Mirabilis' Selys (Odonata, Zygoptera) as a Flagship Species for Aquatic Insect Conservation in South-Eastern Australia

2007·1.2 MB·English

by  T R New

Invertebrate ConservationIssue
The Hemiphlebia damselfly Hemiphlebia mirabilis Selys
(Odonata, Zygoptera) as a flagship species for aquatic insect
conservation in south-eastern Australia
TRNew
DepartmentofZoology,LaTrobeUniversity,Victoria3086
[email protected]
Abstract
TheendemicdamselflyHemiphlebiamirabilisSelyshasbeenafocusofconservationattentionsince
itsrediscovery inVictoriawaspublicised inthemid 1980s. Itwas listed underthe state’sFloraand
Fauna Guarantee Act (FFG) in 1991. Discovery ofadditional colonies has indicated that
Hemiphlebia is far more widespread than earlier supposed, and continued study indicates that it is
variouslysecure orvulnerable in differentplaces-ratherthan ‘endangered’, as previouslythought.
The historyofstudy ofthe species is summarised briefly, and its values in promotingawareness of
insectconservationasa ‘flagshipspecies’ insouthern Australiaarediscussed.{The VictorianNaturalist
124(4)2007,269-272)
Introduction
The Hemiphlebia damselfly Hemiphlebia was the sister-group to all other Odonata.
mirabilis (Fig. 1) is now' also known as the This isolated position, rendering it a dis-
‘Ancient Greenling’ (Theischinger and tinct ‘oddity’ within the order, is implied
Hawking 2006). It is well known as one of by unusual wing venation and the form of
Australia’s most unusual endemic dam- the larval labium. Trueman (1999) reap-
selflies. It is commonlyreferredto as a ‘liv- praisedboth characters and suggested that
ing fossil’, and is treated conventionally as they may in fact be derived, rather than
the only extant member ofthe superfamily primitive as commonly presumed.
Hemiphlebioidea, implying that it is taxo- Hemiphlebia mirabilis is also of interest
nomicallyisolatedwithintheorderOdonata. for its elaborate display behaviour, and is
Indeed, Trueman (1996) believed that it oneofthe smallestOdonata.
Fig. 1.MaleHemiphlebiamirabilis, WilsonsPromontory,Victoria.
Vol. 124 (4) 2007 269
Invertebrate Conservation Issue
Much of its conservation interest arises subsequent searches showed it to occur in
from its putative isolated phylogenetic the Goulburn Valley as well, both at Yea
position, coupled with the belief that it and near the billabong at Alexandra, from
might have become extinct in the mid where Tillyard described the larva and
1970s. duetohabit lossthrough agricultural found the damseltly over a long period
intensification in the Yarra and Goulburn (1906-1931: ANIC records, see Watson
valleys. Victoria. Over that period, a num- 1995) (Trueman et ai 1992). Hemiphlebia
ber of searches failed to yield the insect, was also found to he quite abundant at
which appears always to have been highly localities in north-east Tasmania and on
localised and known from few places. Flinders Island (Endersby 1993: Trueman
Thus. Wells et ai (1983) categorised it as ei ai 1992). with the implication that it
‘endangered', at a time when it was formerly may have occurred more exten-
believed to be extinct, and Moore (1982) sively across the eastern land bridge that
placed it as the highest global priority for linked Tasmania with south-eastern
conservation of the then newly formed Victoria.
Odonata Specialist Group of the World Hemiphlebia is univoltine, with adults
Conservation Union’s Species Survival present from late November to late
Commission. Hemiphlebia was thus February. Adults are very cryptic, and are
something of a ‘holy grail' for Australian inconspicuous when they rest on dense
dragonfly enthusiasts, but it was not until vegetation. The usual habitat is densely
Davies (1985) publicised a record by vegetated seasonal swamps/ billabongs/
Garrison from Wilsons Promontory and lagoons, with shallow (often 20-60 cm
established its presence there for himself, deep) waterandwiththe margins seasonal-
that its continued existence was confirmed, ly dry. Many formerly suitable habitats,
and the conservation status and biology of particularly in the Goulburn and Yarra val-
Hemiphlebia could be appraised in more leys, have been destroyed or degraded
detail. In this note, I recapitulate brieflythe severely by drainage and cattle trampling.
sequence and extent ofdata accumulation Fringing areas with dense reeds or other
on Hemiphlebia^ and indicate how this has emergent vegetation appear to be critical
ledtomore realistic appraisal ofits conser- habitat components, with seasonal desicca-
vation needs, and also explore the wider tion suggesting strongly that Hemiphlebia
context of Hemiphlebia^^ importance in has a well-developed mechanism for over-
developing insect conservation awareness coming periods ofdrought, possibly as the
in Australia. The species is amongst the egg stage. Larvae are small in early spring,
few invertebrates already the focus ofcon- and their main growth phase is from
servation interest at the time FFG came August to November: there appear to be 9
into force, andhasremained soeversince. or 10 instars.
Hemiphlebia was a natural candidate for
Biology andConservation early nomination for protection under
Although H. mirabilis was stated to have FFG, as a formal prelude to preparing an
been described from Port Denison,
Action Statementon its conservation status
Queensland, this locality citation is now and needs. Grounds included in the nomi-
accepted generally as erroneous for Lake nation (April 1990) were that (1) it had
Denison, Victoria, which has long been disappeared from localities in the state
drained but is in the same general area as where it previously occurred; (2) isprimar-
all other mainland distribution records. ily threatened by habitat degradation, par-
Davies (1985) documented a strong colony ticularly involving drainage, damage by
in Wilsons Promontory National Park, cattle, and river regulation: (3) that the
which was explored further in 1987-1988 Wilsons Promontory population was
(Sant and New 1988), to clarify its life threatened by park management practices;
historyfurther, tocharacterise its habitat as and (4) that the species is rare in ternis of
far as possible, and to explore its distribu- abundance and distribution. Together with
tion on the northern part of the park. uncertainties over the recovery from a
Wilsons Promontory was then the only major bum ofthe largest known colony on
place known to support Hemiphlebia^ but
270 The Victorian Naturalist
Invertebrate ConservationIssue
Wilsons Promontory (1987), Hemiphlehia Indeed, ifwe categorise the majorthreats
was a strong candidate for listing, and it to native invertebrates in Australia, the top
was formally listed in May 1991 as one of concerns would be habitat change through
the first batch ofnon-marine invertebrates vegetation clearing, impacts of exotic
tobe sodesignated. (often, invasive)organisms, andagricultur-
Progressive accumulation ofinformation al practices. All are relevant to
on Hemiphlehiahas ledto informal down- Hemiphlehia, with the last-namedthe most
grading of conservation status, with vari- significant impetus forhabitatdegradation.
ous sitesnowregarded as secureorvulner- Nevertheless, and despite evidence of its
able, notwithstanding Watson’s (1995) widespread survival, Hemiphlehia does
commentthat ‘its futurecan be regardedas appearto havebeen lost from some fomier
secure’. inhabited sites, with agriculture and cattle
The major concern for its welfare in the clearly implicated in this decline. The
late 1980s centred on the outcomes of a small number and dispersion of colonies
fire at Wilsons Promontory. The main currently known merits its retention as a
habitat of Hemiphlehia, on Five Mile species ofconservation significance. Some
Road, abutted a fire break mown along a colonies in both range-states are in
road, and a control bum (part ofthe man- National Parks, so that opportunity for
agement strategy to regenerate heathland practical management is present, and
along the northern part of the National methods ofhabitat maintenance are rea-
Park, to reduce ground fuel loads, and to sonably clear - with ambiguities over the
provide abarriertopassage ofmore severe extentofdisturbancethatmaybetolerated.
uncontrolled blazes) got ‘out of control’ It is likely that Hemiphlehia will be more
and swept through the swamp, with poten- widespread than the few current disjunct
tially severe consequences; it was feared records imply, although searches have so
that the damselfly might have been extir- farfailedto confirm this and more detailed
pated. surveys, particularly through the Goulburn
In fact, the mown area, across about half Valley,arewarranted.
the swamp area, remained green.
However, the very dry summer and Discussion
autumn also led to concentration of cattle As well as being a species of significant
seekingwater-atthistime,theregionwas conservation interest as a ‘target’,
part ofa long-term grazing lease, phased Hemiphlehia also has become a notable
out in 1992 - which led to considerable flagship species, as a wider conservation
trampling ofthe swamp. Factors causing ‘tool’. As a member ofa small portfolio of
concern for the colony were (1) loss of ecologically disparate invertebrates target-
emergent vegetation, increasing exposure ed for conservation in Victoria, all of
woafttehre;waatnedr;(3()2)idnecproesaisteidoncaotftlaeshacocnestsh,e ewahrilcyhyewaerrs,e iptrhoamsotheeldpeudndteormFaFkGe minanitys
trampling and dung deposition. people aware ofthe ecological variety of
Subsequently the area was fenced by the invertebratesandtheirconservationneeds.
parksstaffto exclude cattle. The fencewas Flagship species are ‘ambassadors’, help-
left in place for some seven years, whilst ing to communicate importance and con-
the area had a chance to recover. servation lessons to a wider audience and
Subsequent monitoring (New 1993) to increase appreciation ofthe ‘place’ of
showed gradual recovery ofHemiphlehia, invertebrates in natural systems. Because
apparentlyreflectingthatthe mown partof of its presence in National Parks,
the habitat constituted a refuge for part of Hemiphlehiahas had aspecial role in help-
the population, and numbers of adults ing to get invertebrates included in park
gradually increased in the entirely burned conservation agendas. Particularly at
area. Recovery from severe habitat distur- Wilsons Promontory it has been accepted
bance is clearly possible, and it is likely by staff as one of ‘their’ special species,
that Hemiphlehia may have experienced with staffbeing aware ofwhere it occurs
numerous similar catastrophes during its and its significant interest. This increased
longhistory. awareness has had a wider impact. In
Vol. 124 (4) 2007 271
Inverfebrafe Conservation Issue
Australiawe havenocoordinated inventory References
program to document invertebrates in high CaughicyG(1994)Direclioiisinconservationbiology.
quality reserves, and most records are sim- DaJvoiusrnDaAlL,of(A19n8i5m)alHeEmcioplholgeyh6i3a,m2i1r5a-h2i4l4i.s StHys: some
ply serendipitous. Odonata, thanks to notes on distribution and conservation status
recent handbooks (Watson et al. 1991: (Zyaoptcra: Hemiphlebiidae). Odonatologica 14.
Theischinger and Hawking 2006) are En3d3e4r23s3b1y;.ID (1993) A new locality for Hemiphlehia
largely identifiable to species level as mirahilisSelys(Odonata,Hemiphlebiidae). Viclorian
adults and larvae, and an increasing num- MoEonrteomoNlWogi(s1t92832,)4M-5i.nutes ofthe second meeting of
ber ofpark surveys is being instigated as a the lUCN Odonata Specialist Group (1981) (lUCN:
basis for evaluating species' representation Gland).
on reserves, to provide a sound template NewTR(1993).HemiphlehiamirahilisSelys:recovery
from habitat destruction at Wilsons Promontory,
for future complementarity of protected Victoria,Australia,andimplicationsforconservation
areas. management.Odonatologica22,495-502.
The cryptic nature ofIlemiphlehia means SavnattiGoJnaonfdHNeemwipThRleh(1i9a88m)i.raThhielibsioSleolgyysa(nOddcoonnastear:-
that, unlike more conspicuous insects such Hemiphlebiidae) in southern Victoria. Arthur Rylah
as butterflies, most people who support its Institute for Environmental Research, Technical
conservation strongly have never seen it ThReeipsocrhtin8g2e.r Cj and HawkingJ (2006). The complete
alive,butneverthelessacceptitasimportant. field guide to dragonllies ofAustralia (CSIRO
Whereas Hemiphlehia is now known Publishing:Collingwood)
from two states, with the strong implica- Troufeomdaonna.tIeWwHin(g19v9e6n)atAionp.reOldiomninaatroylocgliadciast2i5c,a5n9a-l7y2s.is
tion that it has been distributed more wide- Trueman JWH (1999). The enigmatic Australian
ly in the past (so that present colonies are species Hemiphlehia mirahilis Selys (Zygoptera:
remnant populations), it is still known rHeecmoirpdh.leIbntieorindaetai)o:nafloJurousrhnoartloobfsOedrovnaattioolnosga\n'd2,a1n1e5w-'
from relatively few localities and has not 121
been found west of Melbourne, on King Truem.an JWH. Hoye GA. Hawking.IH. Watson JAL
and New' TR (1992). Hemiphlehia mirahilis Selys:
Island or north-western Tasmania, so that new' localities in Australia and perspectives on
it may never have occurred on the western conservation (Zygoptera: Hemiphlebiidae)
land bridge region. It may well occur else- WaOtdsoonnatoJlAoLgi(c1a99251.).36T7h-e374c.onservation status ofthe
where. but is elusive, and has successfully enigmatic Australian dragontly Hemiphlehia
evaded detection during numerous com- mirahilisSelys. pp. 16-18 in Corbet PS. Dunkle SW
and Ubukata H (eds) Proceedings of the
prehensive surveys ofaquatic invertebrates International Symposium on Conservation of
throughout the state undertaken through Dragonllies and theirHabitats (Japanese Society for
Museum Victoria. It is clearly resilient to WatthseoPnreJsAerLv,atTihoenioscfhBiinrgdes:rKGusahnidro)Abbey HM (1991).
disturbance, but not to loss ofhabitat, and TheAustraliandragonflies.Aguidetotheidentifica-
appears to fly weakly and thus to be a fee- tion.distributionsandhabitatsofAustralianOdonata
ble disperser. Individual site/colony man- We(lClSsIRSOM:,CaPnybleerrRaMandanMdelCboolulrinnes).NM (1983). The
agementisthusthekeytopractical conser- lUCN Invertebrate Red Data Book (lUCN: Gland
vation but, as formany other invertebrates, andCambridge).
‘management’ may mean prevention of
major change or intrusion, and - in some
cases - possibly changing land tenure to
help meet this basic need. Its conservation Received22March2007;accepted28June2007
needs thereby reflect it satisfying both the
‘small population’ (thereby being suscepti-
ble to stochastic effects in small areas) and
the ‘declining population’ (implied, with-
out solid population data, and reflected in
overall decline in range) of Caiighley
(1994).
111 The Victorian Naturalist