For reintroduction in the northern Adelaide coastal plains
Transcript of For reintroduction in the northern Adelaide coastal plains
Yellowish Sedge-skipper butterfly fact sheet For reintroduction in the northern Adelaide coastal plains
Every animal and plant plays a part in shaping where we live, work and
play. When the Yellowish Sedge-skipper butterfly became regionally extinct
from the northern Adelaide coastal plains it could no longer play that part
(i.e. pollinate flowers). Bringing it back will not only restore what it used to
do in the region, it will allow many other native plants and animals to play
their parts. In some cases, native insect species can even control major
horticultural pests.
Restoring a habitat for a species that can no longer survive there has many
potential benefits for native biodiversity, local communities and horticultur-
alists. The habitat must be healthy for the species to return and remain but
this requires the cooperation of many people in the community.
Why reintroduce a butterfly?
Which butterfly? Which habitat?
Thatching Grass sedgelands
- Long lived
- Low maintenance
- Habitat for native animals
- Host predators that control thrips
- Tolerates flooding & drying
- Tolerates fresh to brackish water
The Yellowish Sedge-skipper (Hesperilla flavescens
- Fig. 1), used to flourish in the northern Adelaide
coastal plains. It has not been seen in the area
since 1985 and is believed to be regionally extinct.
It lives in Thatching Grass (Gahnia filum)
sedgelands (Fig. 2), which used to be common in
the region. It now lives in sedgelands in south
eastern Australia ranging, in isolated patches, from
Eyre Peninsula to south west Melbourne, Victoria.
The Nature Conservation Society of South Australia
is working with Natural Resources Adelaide & Mt
Lofty Ranges and BirdLife Australia to restore the
habitat of this butterfly and reintroduce to its
historic range. Yellowish Sedge-skippers
- Close to 3 cm wingspan
- Larval stage lasts 1 yr
- Impetus to restore native
habitats
- Increase native biodiversity
- Attraction for nature lovers
Figure
1: H
esp
erilla flave
scens (Y
ello
wish
Sed
ge-skip
per). P
ho
to: A
lex S
tola
rski
The Yellowish Sedge-skipper study is part of the Samphire Coast Icon Project, supported by the Adelaide
and Mount Lofty Ranges Natural Resources Management Board through funding from the Australian Government.
Figure 2: Male YSS specimens from the top (above) and underwing
(below) and a healthy Thatching Grass tussock. Photo: C. Butcher
Figure 3: Late instar YSS larva. Photo: C. Butcher
Benefits to horticulturalists
Benefits to communities
Horticultural pests are costing local growers dearly either through money lost
due to damaged crops or money spent trying to reduce the damage (e.g.
pesticide). One of the most costly pests is the Western Flower Thrip
(Frankliniella occidentalis), which damages crops directly and also transmits
Tomato Spotted Wilt Virus (Fig. 4).
Thatching Grass sedgelands host native predatory and parasitic insects that
target these thrips. A study revealed that these insects, Eulophid Wasp
(Ceranisus menes ) and Scelionidae Wasps (Telenomus spp.), can be used as a
biocontrol agent that have no known negative impact on crops. The study also
revealed that Thatching Grass is also not attractive for the thrip to seek refuge
like weed species are (Wood and Coleman, 2016).
Horticulturalists that adopt Thatching Grass around their enterprises as part of
an integrated pest management solution could save a great deal of money.
Everybody loves butterflies! The northern Adelaide coastal plains is full of
environmental treasures that are waiting to be promoted. The region has the
Adelaide Dolphin Sanctuary and the newly proclaimed Adelaide International
Bird Sanctuary National Park - Winaityinaityi Pangkara. Furthermore, another
butterfly species being restored in the region, the Bitterbush Blue (Theclinesthes
albocincta). With enough community and government support, starting with
these butterflies, the region could become a butterfly hotspot.
Engaging local schools, community groups and volunteer organisations to get
involved in conservation and habitat restoration projects to bring back the
butterfly will instil a sense of ownership in the land and further promote
environmental stewardship for the region. It will also improve visual amenity
and increase native wildlife, attracting nature lovers to the region, which will
also support local communities and businesses.
Areas of interest The areas of interest are on low-lying wetland
habitats in the northern Adelaide coastal plains
spanning from the Port River Expressway to north of
Two Wells (Fig. 3).
Thatching Grass is suited to low, relatively flat and
open areas (not shaded) that can be seasonally
flooded (fresh water).
The more Thatching Grass sedgeland like this in the
area, the better chance we have of bringing the
butterfly back and maintaining their presence.
There are currently several areas of Thatching Grass
sedgeland that are being restored, protected and
expanded. These sedgelands are both on private and
public land. Each site is unique and requires its own
management plan.
Adelaide CBD
Figure 3: The northern Adelaide coastal plains; part of the former habitat
of the Yellowish Sedge-skipper and Thatching Grass sedgelands
Figure 4: Above: Frankliniella
occidentalis (Western Flower Thrip).
Photo: Lyle Buss. Below: tomatoes
infected with Tomato Spotted Wilt
Virus (photo: anon).
Figure 5: Mature Thatching Grass
tussocks amongst planted seedlings at
Salisbury Greenfields 3 Wetlands
Photo : C. Butcher
Creating a butterfly habitat
One of the best way to create a habitat for this butterfly is to have an existing healthy patch of Thatching Grass
tussocks, which can be added to. The Yellowish Sedge-skipper relies on Thatching Grass* to lay its eggs; its larvae
survive on its leaves until it emerges as a butterfly. Thatching Grass grow in a variety of soil types and thrive where
fresh to brackish water pools over winter and may dry out in summer (Coleman and Coleman, 2000).
They can be planted with close spacing (0.5-1 m) in full sun but close to native flowering trees (Fig. 6 & 7). The
butterfly prefers open and flat sedgeland for mating displays. Females need clear accesses to the side of the
tussock to lay their eggs (Fig. 7). Habitats for this butterfly can be quite small. Populations are known to breed on
clumps of only 150 plants (30 young) (Alex Stolarski pers.com. 2017).
What to look for
Figure 6: Guarded Gahnia filum (Thatching Grass) seedlings at
Salisbury Greenfields 3 Wetlands Photo: C. Butcher
Figure 7: Small natural Thatching Grass sedgeland with Melaleuca
trees on Yorke Peninsula. Photo: C. Butcher
Figure 8: A large Hesperilla flavescens shelter made between
three or four Gahnia filum leaves. Photo: C. Butcher
Figure 9: A Hesperilla flavescens larva, fifth instar, this will
pupate (metamorphose) in 1-2 months. Photo: C. Butcher
*Also Gahnia deusta (Heathy Saw-sedge)
Once the butterfly is reintroduced to the region we will start to see signs of it in the sedges. We anticipate they
will spread across the region where habitats are suitable. You will know if you have this butterfly in you park or on
your property if you find one of its shelters (Fig.8). The larvae create shelters between the leaves of the Thatching
Grass where they spend their days protected from the elements and predators. They emerge at night to feed.
The larva will build a shelter to suit its current growth phase (instar) (Fig. 9). It’s common to find 1-2 old shelters
on a tussock. Shelters are normally on the outer leaves of a tussock and they’re usually made between fresh,
green leaves.
Yellowish Sedge-skipper fact sheet
More information
Councils, state government, NGOs and community groups: Local and state government agencies are working together with
non-government organisations and community groups to help improve the Thatching Grass habitat for the Yellowish Sedge-
skipper. Visit their websites or offices to discuss what you want to know or how you can help.
City of Salisbury, City of Playford and Adelaide Plains Council
Natural Resources Adelaide Mt Lofty Ranges
Nature Conservation Society of South Australia (NCSSA)
Management plans and projects: One of the founding documents for this effort is the “Local recovery plan for the Yellowish
Sedge-skipper and Thatching Grass” (Coleman and Coleman, 2000). The Local Recovery Plan helped lead to the inclusion of
this butterfly and its habitat as conservation priorities in the Metropolitan Adelaide and Northern Coastal Action Plan (2009).
The Local Recovery Plan was reviewed in 2015 to see how close we were to reaching our goals. The NCSSA has completed a
feasibility assessment for the reintroduction of the species (Butcher, 2017).
Coleman, P & Coleman, F (2000) Local recovery plan for the Yellowish Sedge-skipper and Thatching Grass. Saint Kilda, South Australia: Delta
Environmental Consulting.
Coleman, P (2015) Progressing the Local Recovery Plan: Yellowish sedge-skipper butterfly & Thatching Grass. Prepared for: Natural Resources
Adelaide & Mt Lofty Ranges and Australian Government, Samphire Coast Icon Project Biodiversity Fund.
Caton, B, Fotheringham, D, Krahnert, E, Pearson, J, Royal, M and Sandercock, R (2009) Metropolitan Adelaide and Northern Coastal Action
Plan. Prepared for Adelaide & Mount Lofty Ranges Natural Resource Management Board and Department for Environment and Heritage,
Adelaide.
Butcher, C (2017) Yellowish Sedge-skipper Butterfly Reintroduction Feasibility Project – Final Report. Prepared for the Nature Conservation
Society of South Australia for the Adelaide and Mt Lofty Natural Resources Management Board (Samphire Coast Icon Project).
Specialist pest management research: There is some very promising research examining using native plants (and animals) as
part of an integrated pest management strategy. This is specifically targeted at common horticultural pests. Read the
following reports for more information.
RIRDC (Rural Industries Research and Development Corporation) (2011) Revegetation by Design - Promoting the ‘on-farm’ use of native
vegetation as agents of ‘natural pest control’. RIRDC Publication No. 11/002. Canberra: Union Offset Printing.
Wood, G and Coleman, P (2016) Gahnia filum: Insect use of Thatching Grass. Prepared for: Adelaide and Mt Lofty Ranges Natural Resource
Management Board.
Other research from the literature: There has been a great deal of work on butterfly conservation in Australia, including the
close relative Hesperilla flavescens flavescens in Victoria.
Braby, M (2000) Butterflies of Australia: Their Identification, Biology and Distribution. CSIRO Publishing.
Grund, R (1997) Interim Recovery Plan. Recovery of Hesperilla flavescens flavia (Lepidoptera: Hesperiidae), the yellowish skipper. Report to
National Heritage Trust, Canberra.
Grund, R (2003) The yellow sedge-skipper on Yorke Peninsula. Prepared for Butterfly Conservation South Australia Inc.
New, T (2011) Butterfly conservation in South-Eastern Australia. 1st ed. New York: Springer, pp.55-65.
New, T and Sands, D (2002) Conservation Concerns for Butterflies in Urban Areas of Australia. Journal of Insect Conservation, 6(4), 207-215
New, T and Sands, D (2004) Management of threatened insect species in Australia, with particular reference to butterflies. Australian Journal of
Entomology, 43(3), 258-270.
Relf, M and New, T (2009) Conservation needs of the Altona Skipper butterfly, Hesperilla flavescens flavescens Waterhouse (Lepidoptera:
Hesperiidae), near Melbourne, Victoria. Journal of Insect Conservation, 13(2), pp.143-149.
Savage, E (2002) Options and techniques for managing Chaffy Saw-sedge (Gahnia filum) as habitat for the Altona Skipper butterfly (Hesperilla
flavescens flavescens). Conservation and environmental management, occasional paper series. Parks Victoria, Melbourne.
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