Graceful Sunmoth (Synemon gratiosa)
Graceful Sunmoth (Synemon gratiosa) is a small day-flying sun-moth (Castniidae), listed for the Midwest and Swan regions of Western Australia. It is DBCA Priority 4 (rare, near threatened or in need of monitoring) on the Threatened and Priority Fauna List, and not listed under the EPBC Act. The graceful sun-moth occurs on the coast and Swan Coastal Plain between Kalbarri and Binningup.
Conservation status
Western Australia, WA Threatened and Priority Fauna List: Priority 4.
Seasonal planning
The highlighted months are a general guide from the group biology.
Seasonal evidence: General, not site-specific.
Check local advice; timing varies between years.
- Main activity or breeding period: Plan surveys and avoid disturbance in these months where possible.
Identification: Appearance
Graceful Sunmoth is a small day-flying sun-moth (Castniidae). Reliable identification needs a specialist.
A species-specific field description is not summarised here. Use the original description and museum specimens for identification.
Identification: Similar species
Related species in the same genus or group can look alike and may occur nearby. Confirm identity with a taxonomist before relying on a record.
Distribution: Known records
Listed for the Midwest and Swan regions.
The Atlas of Living Australia holds 70 records at 8 distinct 0.1-degree locations, between latitude -32.3 and -31.4, longitude 115.4 to 116.0. Coordinates are often generalised for listed species, so treat this as an indicative area, not a boundary.
Distribution: Group pattern
The graceful sun-moth occurs on the coast and Swan Coastal Plain between Kalbarri and Binningup. Its larvae feed only on two mat-rushes, Lomandra maritima and L. hermaphrodita.
Distribution: WA listing
DBCA lists the species for the Midwest and Swan regions.
Habitat: Habitat
Coastal heath on secondary Quindalup dunes with Lomandra maritima, thought to be the preferred habitat, and Banksia woodland on deep sands with Lomandra hermaphrodita.
Coastal heath on secondary Quindalup dunes with Lomandra maritima, thought to be the preferred habitat, and Banksia woodland on deep sands with Lomandra hermaphrodita.
Species-specific habitat preferences have not been published in detail; this is based on the group and the listed locality.
Habitat: Site interpretation
Treat matching habitat in or near the listed locality as potentially occupied until a qualified survey shows otherwise.
Foraging habitat: Diet
Larvae tunnel in the roots and rhizomes of their Lomandra host plants.
Larvae tunnel in the roots and rhizomes of their Lomandra host plants.
Breeding habitat: Breeding
The life cycle takes two or more years. Adults live about two to ten days and fly from mid-February to early April, most abundantly in the first half of March.
The life cycle takes two or more years. Adults live about two to ten days and fly from mid-February to early April, most abundantly in the first half of March.
Sheltering habitat: Shelter
Larvae live underground in Lomandra roots and rhizomes.
Larvae live underground in Lomandra roots and rhizomes.
Threats: Threats
Clearing for development, particularly around Perth, and fragmentation of the Banksia woodland subpopulations.
Clearing for development, particularly around Perth, and fragmentation of the Banksia woodland subpopulations.
Threats: Works risk
Removal of Lomandra maritima or L. hermaphrodita and soil disturbance around them. Only surveys in the flight period, mainly March, can show the moth is absent.
Survey methodology: 1. Desktop review and design
Follow the EPA Western Australia technical guidance and engage specialists with the right licences.
Use the EPA Western Australia guidance on short range endemic invertebrates: desktop review of museum and survey records, targeted habitat searches, and collection or photography under the right licence.
Survey methodology: 2. Field survey
Search the habitat named in this profile by hand (litter, logs, rocks, burrows or host plants), and repeat after rain or in the cooler months when many short range invertebrates are active.
Survey methodology: 3. Identification and limits
Identification often needs a specialist taxonomist and voucher specimens. A non-detection is not proof of absence.
Vegetation associations: Woodland
Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.
Coastal heath on secondary Quindalup dunes with Lomandra maritima, thought to be the preferred habitat, and Banksia woodland on deep sands with Lomandra hermaphrodita.
Automatically indexed from existing profile text. Not a verified preference, mapped occurrence or habitat requirement. Check the original source and regional qualifiers before use.
Evidence: Unreviewed profile-derived candidate
Confidence: Not independently verified
Region: Scope as described in the quoted profile text; not independently verified. Profile states: WA.
Habitat use: general
Vegetation associations: Heath
Coastal heath on secondary Quindalup dunes with Lomandra maritima, thought to be the preferred habitat, and Banksia woodland on deep sands with Lomandra hermaphrodita.
Automatically indexed from existing profile text. Not a verified preference, mapped occurrence or habitat requirement. Check the original source and regional qualifiers before use.
Evidence: Unreviewed profile-derived candidate
Confidence: Not independently verified
Region: Scope as described in the quoted profile text; not independently verified. Profile states: WA.
Habitat use: general
Ecosystem associations
Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.
No species-specific ecosystem association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.
Soil and substrate associations: Sandy soils or sand
Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.
Coastal heath on secondary Quindalup dunes with Lomandra maritima, thought to be the preferred habitat, and Banksia woodland on deep sands with Lomandra hermaphrodita.
Automatically indexed from existing profile text. Not a verified preference, mapped occurrence or habitat requirement. Check the original source and regional qualifiers before use.
Evidence: Unreviewed profile-derived candidate
Confidence: Not independently verified
Region: Scope as described in the quoted profile text; not independently verified. Profile states: WA.
Habitat use: general
Water and wetland associations
Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.
No species-specific water association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.
Fauna records and mapped habitat: Not yet analysed
Record locations can be overlaid with mapping, but record frequency alone does not measure habitat preference. No species is excluded from desktop assessments by this analysis.
No quality-controlled record-to-map analysis has been completed for this species. The existing generalised distribution dots and indicative range polygons have not been treated as precise occurrence coordinates.
A defensible run needs dated, independently attributable records, coordinate uncertainty, duplicate and captive-record checks, layer versions and regional scope. Preference and absence require additional survey-effort and detection evidence.
Habitat limitations and contrary evidence: No supported exclusion recorded
Not recorded is not the same as cannot occur. Low suitability, resident habitat, breeding habitat and occasional movement are different conclusions.
This library has not established a vegetation, ecosystem or soil-type exclusion for this species. This does not mean all habitat is suitable; the evidence needed to justify an exclusion has not been assembled.
Habitat limitations and contrary evidence: Before using a negative association
- Confirm the taxon, geographic region, life stage and habitat function covered by the evidence.
- Check survey methods, season, repeated effort and detectability before interpreting non-detection.
- Investigate credible contradictory records and microhabitats absent from broad mapping.
- Do not convert a missing map class, low record count or failed data request into species absence.
Before disturbance: 1. Pre-start review
Confirm whether the project could affect the species before any works begin.
Check the project footprint against the listed locality, DBCA records and any survey results. Map habitat that matches this profile.
Before disturbance: 2. Approvals
Taking or disturbing listed threatened fauna in WA needs authorisation under the Biodiversity Conservation Act 2016. Seek DBCA advice early.
Before disturbance: 3. Crew briefing
Brief crews on the habitat to avoid, the exclusion areas and who to call if the species or its habitat is found.
During disturbance: 1. Protect habitat
Keep works inside the approved footprint.
Removal of Lomandra maritima or L. hermaphrodita and soil disturbance around them. Only surveys in the flight period, mainly March, can show the moth is absent. Fence or flag known habitat and keep vehicles, stockpiles and spoil out of it.
During disturbance: 2. Stop and report
If the species or suspected habitat is found outside the approved area, stop work at that spot and contact the project ecologist and DBCA.
After disturbance: 1. Record outcomes
Record what was done.
Record any sightings, specimens, habitat lost or retained and any incidents, and submit records to DBCA as required by the authorisation.
Rehabilitation: 1. Restore
Restore disturbed areas where possible.
Return surface materials, logs, rocks and litter, restore drainage and revegetate with local species. Use hygiene controls for dieback in the south-west.
Sources
- Threatened and Priority Fauna List, 1 July 2025, WA Department of Biodiversity, Conservation and Attractions: https://library.dbca.wa.gov.au/static/Journals/082696/082696-2025.07.01.xlsx
- Graceful sun-moth survey guidelines, WA Department of Environment and Conservation: https://library.dbca.wa.gov.au/FullTextFiles/070291.pdf
- Conservation Advice for Synemon gratiosa (graceful sun-moth), WA Department of Environment and Conservation: https://library.dbca.wa.gov.au/static/FullTextFiles/922303.pdf
- Atlas of Living Australia: Synemon gratiosa, Atlas of Living Australia: https://bie.ala.org.au/species/https://biodiversity.org.au/afd/taxa/fb531b39-fd0b-4afb-9115-5e4f4691cf7f
- Technical Guidance: Sampling of short range endemic invertebrate fauna (2016), Environmental Protection Authority, Western Australia: https://www.epa.wa.gov.au/sites/default/files/Policies_and_Guidance/Tech%20guidance-%20Sampling-SREs-Dec-2016.pdf
- Atlas of Living Australia: scatterplot case study and survey-effort limitations, Habitat evidence reference: https://support.ala.org.au/support/solutions/articles/6000208426-scatterplot-case-study