Biodiversity

Species Profile and Threats Database


For information to assist proponents in referral, environmental assessments and compliance issues, refer to the Policy Statements and Guidelines (where available), the Conservation Advice (where available) or the Listing Advice (where available).
 
In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.

EPBC Act Listing Status Not listed under EPBC Act
Listing and Conservation Advices NON-CURRENT Commonwealth Listing Advice on Synemon gratiosa (Threatened Species Scientific Committee (TSSC), 2008aei) [Listing Advice].
 
Commonwealth Listing Advice on Synemon gratiosa (Graceful Sun Moth) (Threatened Species Scientific Committee (TSSC), 2013aw) [Listing Advice].
 
Recovery Plan Decision Recovery Plan not required, species delisted from the EPBC Act (18/05/2013).
 
Adopted/Made Recovery Plans
Federal Register of
    Legislative Instruments
Inclusion of species in the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (69) (19/12/2008) (Commonwealth of Australia, 2008d) [Legislative Instrument].
 
Amendment to the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (143) (07/05/2013) (Commonwealth of Australia, 2013m) [Legislative Instrument].
 
Non-statutory Listing Status
WA: Listed as P4 (Priority Flora and Priority Fauna List (Western Australia): April 2014 list)
Scientific name Synemon gratiosa [66757]
Family Castniidae:Lepidoptera:Insecta:Arthropoda:Animalia
Species author  
Infraspecies author  
Reference ANZECC Threatened Fauna List May 2000
Distribution map Species Distribution Map not available for this taxon.
Illustrations Google Images

Synemon gratiosa was removed from the Environment Protection and Biodiversity Conservation Act 1999 list of threatened species on 18 May 2013,

Scientific name: Synemon gratiosa

Common name: Graceful Sun Moth

The genus Synemon is well researched and there are 45 identified Australian species (24 from south-west Western Australia), 160 from Central and South America and two from Asia (Edwards 1997; WAISS 1993).

The Graceful Sun Moth is a medium sized diurnal flying sun moth that is similar in appearance to a butterfly (WAISS 1993). It typically has dark forewings and brightly coloured hind wings, and generally looks and behaves like a butterfly (WA DEC 2011). The upper surface of the forewings are dark grey-black with obscure light grey markings, whereas the upper surface of the hind wings and the undersides of both pairs of wings are bright orange with some darker grey-black bands (WA DEC 2011). The extent of the orange colouration is variable, and specimens become less brightly coloured as they age (WA DEC 2011). Images of the Graceful Sun Moth are available from online information sheets (e.g. Bishop et al. 2010a; WA DEC 2011).

The Graceful Sun Moth has a wingspan of 25–35 mm, with males smaller than females (WA DEC 2011). Adults are active only in autumn, predominantly in March. The larvae are white and hairless (WAISS 1993). Adults are usually inconspicuous when settled, displaying only the dark forewings, but the hind wings are exposed in flight and they are easily recognised (WA DEC 2011).

General range

The Graceful Sun Moth occurs within the Swan, South West and Midwest WA DEC regions, and the South-west, Swan and Northern Agricultural Natural Resource Management regions (WA DEC 2011).

The range of the Graceful Sun Moth is from Namburg National Park (near Dandaragan) in the north to Mandurah in the south (Bishop et al. 2010). A list of known sites is provided by WA DEC (2011).

There is insufficient data to determine how many subpopulations of Graceful Sun Moth there are. Previously, it was suggested that at least nine subpopulations were known (WAISS 1997b; WA CALM 2005a), however, recent targeted surveys by WA DEC have resulted in a significant range extension (WA DEC 2011). Further targeted surveys are scheduled for early 2011 (WA DEC 2011).

A number of sites where the Graceful Sun Moth has previously been recorded have been lost as the result of habitat clearance (WA CALM 2005a). For instance, a location where a collection was made in 1996 has since been cleared for urban development (TSSC 2008aed). These lost populations are evidence of a decline in the known range of the Graceful Sun Moth, however, it is difficult to determine the effects of particular threats or the impact on the population size (TSSC 2008aei).

Extent of occurrence

In 2010, the extent of occurrence for the Graceful Sun Moth was estimated to be 2015 km² (Bishop et al. 2010). This extent is substantially greater than previous estimates (i.e. 230 km², TSSC 2008aei).

Area of occupancy

Between 2000–2010, the Graceful Sun Moth was recorded at 49 sites (WA DEC 2011), with a surveyed area of occupancy of 25 km² and a maximum estimated area of occupancy of 42.6 km². The 2010 surveys also indicated that the species was locally extinct at a further 14 sites (WA DEC 2011). Nevertheless, occupancy estimates are substantially greater than previous approximations (i.e. 18 km², TSSC 2008aei).

Fragmentation

Prior to 2009, the distribution of the Graceful Sun Moth was considered highly fragmented (e.g. WA CALM 2005a). However, as new populations have been discovered on secondary dunes, the inferred level of fragmentation has decreased (WA DEC 2011).

Targeted surveys

WA DEC carried out a targeted survey program for Graceful Sun Moth in 2010, resulting in a significant range extension from that known previously (WA DEC 2011). The surveys located a number of large populations as well as populations on conservation estate (WA DEC 2011). This new information on habitat and distribution has led WA DEC to consider that further surveys are essential to clarify its distribution and the appropriate conservation response (WA DEC 2011).

Systematic surveys

In the 1990s and 2000s, over 40 sites on the Swan Coastal Plain were systematically surveyed for butterflies and day-flying moths (Pollard & Yates 1993; Williams in prep.). At each site, a fixed-route transect of 1–6 km in length was walked every two weeks during the flight period, and all butterflies and day-flying moths within 5 m of the observer were identified and tallied.

There is insufficient data to estimate the size of all known subpopulations of the Graceful Sun Moth, and there is insufficient information to calculate a reliable estimate of the total number of mature individuals. In 2010, the largest population count had been recorded in Yalgorup National Park (WA DEC 2011).

Based on comparisons between transect counts and mark-recapture estimates of butterflies (Pollard & Yates 1993), population sizes of the Graceful Sun Moth are typically one order of magnitude larger than transect counts on a given day. For example, a one day observation of 12 would suggest approximately 120 individuals at the site.

Fluctuations

There is no evidence to suggest that the Graceful Sun Moth undergoes any natural changes in extent of occurrence or area of occupancy. Limited information on annual fluctuations in population numbers shows no evidence of extreme fluctuations. Transect surveys conducted over three consecutive years at Warwick Bushland (2003–2005) and at Koondoola Bushland (2002–2004), have recorded consistently low numbers of individuals. At Warwick Bushland, numbers observed in the three years during the main flight period (two surveys each year) were 12, 12 and four. At Koondoola Bushland, numbers observed in the three years during the main flight period (two surveys each year) were three, one and one (WA CALM 2005a).

A list of sites that have been recorded in conservation reserves can be found in the WA DEC conservation advice (WA DEC 2011).

General habitat

Graceful Sun Moth is associated with two habitat types:

  1. Coastal heathland on Quindalup dunes where it is restricted to secondary sand dunes due to the abundance of the preferred host plant Lomandra maritima. Targeted surveys by WA DEC in 2010 indicate that Graceful Sun Moth is recorded at substantially higher rates on the L. maritima habitat and is therefore more numerous/dense in this coastal habitat (WA DEC 2011).
  2. Banksia woodland on Spearwood and Bassendean dunes, where the second known host plant L. hermaphrodita is widespread. The relative contribution of the Banksia woodland (L. hermaphrodita) habitat to the total population and area of occupied habitat of the Graceful Sun Moth is small (WA DEC 2011).

The remaining remnant habitat is severely fragmented, with most subpopulations disjunct and separated by urban and agricultural areas that limit or prevent dispersal (WA DEC 2011).

Specific habitat descriptions

Koondoola Regional Bushland (120 ha), Errina Road Bushland (8 ha), Marangaroo Bushland (33 ha), Landsdale Park (16 ha), Shenton Bushland (20 ha) and Warwick Conservation Area (58 ha) are all located on Spearwood dune soils; with low open woodlands or forest dominated by Banksia and Eucalyptus (Williams 2003).

Warwick Conservation Area is divided into three major fragments by a road, high school and playing fields. This area has been subject to greater disturbance from fire and weed invasion, and only two of the fragments are occupied by the Graceful Sun Moth (Williams 2003).

Gumblossom Reserve (2 ha) is located on Quindalup dune soils, with open shrubland dominated by Dryandra, Melaleuca and Acacia and open Banksia woodlands (WA CALM 2005a).

Whiteman Park (1548 ha) is located on Bassandean dune soils and is dominated by low open Banksia woodlands (WA CALM 2005a).

Koondoola Bushland, Marangaroo Bushland, Landsdale Bushland and Errina Road Bushland are within the Swan Coastal Plain Threatened Ecological Community '20a - Banksia attenuata woodland over species-rich dense shrublands' which is listed as Endangered in Western Australia (WA CALM 2005a).

The Graceful Sun Moth is univoltine. Adults breed only once, in February–April each year, and have a short flight period of approximately one to two weeks (WA DEC 2011). They are active during daylight and may not fly if the weather is cool, overcast or windy (WA DEC 2011).

The larvae tunnel within the roots or rhizomes of the host plants (L. maritima and L. hermaphrodita), upon which they then feed (WA DEC 2011). It is not yet known how long the Graceful Sun Moth takes to complete its life cycle, but, based on similar species it is likely to be one year or possibly two years (WA DEC 2011).

Graceful Sun Moth males establish small territories in open areas and often employ tracks or firebreaks for this purpose. This behaviour markedly increases their detectability. In contrast, females are thought to practice male avoidance after mating, as this is a common behavior in species with a similar breeding strategy. This contrasting detectability is reflected in the observed sex-ratio: approximately 90% of all individuals detected in track-based surveys are males (WA CALM 2005a).

Two known food plants for the Graceful Sun Moth are L. hermaphrodita and L. maritima (McNamara 2009).

Adults of the Castniidae are diurnal (Common 1990), emerging during hot weather in bright sunshine during summer and autumn (Chapman 2002); predominantly March.

Graceful Sun Moth males are sedentary, but the extent to which females disperse is unknown. Based on mark-recapture studies of butterflies with similar social organisation in the same habitat, it is thought that females disperse less than 1 km from their colony of birth and are unlikely to cross unsuitable habitat (WA CALM 2005a).

Despite being able to fly, most species of butterflies and day-flying moths that have been studied, both in south-west Australia and elsewhere in the world, will not disperse across unsuitable habitat. These species rarely disperse "more than a few hundred metres (if that) during their lifetime" (Williams 2003).

Detectability

Adult Graceful Sun Moths are usually inconspicuous when settled, displaying only the dark forewings, but when they fly the hind wings are exposed and they are easily recognised (WA DEC 2011). Images of the species are available from online information sheets (e.g. Bishop et al. 2010a; WA DEC 2011).

Field survey methods

A standard technique for surveys of Graceful Sun Moths has been prepared by Bishop and colleagues (2010a). Key methods include (Bishop et al. 2010a):

  • Surveys should focus on the two known vegetation types: coastal heathland on Quindalup dunes, thought to be the preferred habitat, where it is restricted to secondary sand dunes due to the abundance of the host plant L. maritima; and Banksia woodland on Spearwood and Bassendean dunes, where the second known host plant L. hermaphrodita is widespread (this description has been taken from WA DEC 2011).
  • Surveys should be timed between late February and early April; only March surveys can prove that Graceful Sun Moths are not present at a site.
  • Weather should be warm (20–32 °C), sunny, between 10 am and 3 pm, calm wind conditions (< 18 km²) and prior to the onset of a sea breeze.
  • Surveys around host plants should be prioritised (i.e. L. maritima and L. hermaphrodita).
  • Repeat surveys during flight period are essential (four surveys in coastal heathland and six surveys in Banksia woodland).
  • Transect length should follow the standard butterfly walk transect method as described by Pollard and Yates (1993).

Use of aerial photography

It is possible to identify the coastal dune systems where Graceful Sun Moth have been located on air photographs and therefore identify areas of similar landform that might also support the species (WA DEC 2011). The larger reserves in the Midwest Region appear to have extensive areas of these dunes (exceeding 15 km² in total). Further surveys of these areas for the food plant, and the presence of the Graceful Sun Moth, are required to confirm the assumption that areas of coastal dune preferred habitat can be identified from aerial photography (WA DEC 2011).

If it is shown to be possible to correctly identify the coastal dune habitat of the Graceful Sun Moth from aerial photography or other mapping, there are likely to be additional areas of similar landform in private property and other lands in the WA DEC Midwest Region (WA DEC 2011).

Chapman (2002) provided a list of aims for the conservation of the Graceful Sun Moth on the Swan Coastal Plain in an unsubmitted draft grant application, and included:

  • research history and ecology
  • collate historical distribution on the Swan Coastal Plain
  • increase public awareness of this species and the importance of remnant urban bushland on the Swan Coastal Plain
  • survey locations where this species may occur to establish current distribution, abundance and habitat requirements.

Management documents for the Graceful Sun Moth include:

  • Survey guidelines for the Graceful sun-moth (Synemon gratiosa) & site habitat assessments (Bishop et al. 2010a).
  • Graceful Sun-moth surveys and habitat assessments across the Swan, South West and southern Midwest Region (Bishop et al. 2010); which includes further survey methods.
  • Management documents for the Golden Sun Moth (Synemon plana, occurring in south-east Australia), can be found on the Golden Sun Moth SPRAT profile.

No threats data available.

Bishop C., M. Williams, D. Mitchell & T. Gamblin (2010a). Survey guidelines for the Graceful sun-moth (Synemon gratiosa) & site habitat assessments. [Online]. Perth, Western Australia: Department of Environment and Conservation. Available from: http://www.dec.wa.gov.au/content/view/5695/1813/.

Bishop C., M. Williams, D. Mitchell, A. Williams, J. Fissioli & T. Gamblin (2010). Conservation of the Graceful Sun-moth: Findings from the 2010 Graceful Sun-moth surveys and habitat assessments across the Swan, South West and southern Midwest Regions. Interim report. Kensington, Western Australia: Department of Environment and Conservation.

Chapman, T. (2002). Decline of the Graceful Sun Moth Synemon gratiosa (Westwood 1877) on the Swan Coastal Plain. Draft manuscript. Draft manuscript. Perth: Department of Conservation and Land Management.

Common, I.F.B. (1990). Moths of Australia. Melbourne: Melbourne University Press.

Edwards, T. (1997). Moths in the sun. ANIC News. 10:1-3.

McNamara, K. (2009). Brighton Development - Graceful Sun Moth. Letter regarding moth surveys on the Swan Coastal Plain.

Nielsen, E.S., E.D. Edwards & T.V. Rangsi (1996). Monographs on Australian Lepidoptera. Canberra: CSIRO Publishing.

O'Dwyer, C., S. Hadden & A. Arnold (1998). Golden sun moth Synemon plana action statement No. 106. Victoria: Department of Natural Resources and Environment.

Pollard, E. & T.J. Yates (1993). Monitoring butterflies for Ecology and Conservation. London: Chapman and Hall.

Threatened Species Scientific Committee (TSSC) (2008aed). NON-CURRENT Commonwealth Conservation Advice on Synemon gratiosa. [Online]. Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/66757-conservation-advice.pdf.

Threatened Species Scientific Committee (TSSC) (2008aei). NON-CURRENT Commonwealth Listing Advice on Synemon gratiosa. [Online]. Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/66757-listing-advice.pdf.

Western Australia Department of Conservation and Land Management (WA CALM) (2005a). Records held in CALM's Fauna Database and rare/priority fauna files. Perth, Western Australia: WA CALM.

Western Australia Department of Environment and Conservation (WA DEC) (2011). Conservation Advice for Synemon gratiosa (graceful sun-moth) - January 2011. [Online]. Perth: WA DEC. Available from: http://www.dec.wa.gov.au/content/view/6296/1/.

Western Australian Insect Study Society (WAISS) (1993). Moth studies in the CSIRO. Western Australian Insect Study Society Inc. Newsletter. April:2-4.

Western Australian Insect Study Society (WAISS) (1995). Western Australian Insect Study Society Inc. Newsletter. April:7.

Western Australian Insect Study Society (WAISS) (1997b). Excursion. Western Australian Insect Study Society Inc. Newsletter. April:5.

Williams, M. (2003). Effect of fire on butterflies. Western Wildlife. 7(4):1 & 4.

Williams, M.R. (in prep.). Methods for assessing butterfly biodiversity in temperate regions: a literature review and recommendations based on surveys in southwestern Australia.

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This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.

Citation: Department of the Environment (2014). Synemon gratiosa in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Fri, 25 Jul 2014 17:39:07 +1000.