Jalmenus eubulus - critically endangered species listing

NSW Scientific Committee - final determination

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the butterfly Jalmenus eubulus Miskin, 1876 as a CRITICALLY ENDANGERED SPECIES in Part 1 of Schedule 1A of the Act. Listing of Critically Endangered species is provided for by Part 2 of the Act.

 

The Scientific Committee has found that:

 

1. Jalmenus eubulus Miskin, 1876 (Lepidoptera: Lycaenidae) is a striking medium-sized butterfly (male wingspan 32 mm and female wingspan 37 mm) that has recently been recognised as a separate species from the closely related Imperial Hairstreak, J. evagoras (Donovan), being distinct in morphology, ecology and genetics (Eastwood et al. 2008). The species was formerly regarded as a subspecies of J. evagoras. The morphological differences between J. eubulus and J. evagoras are subtle. The distinction between the species is detailed in Eastwood et al. (2008, page 413) as: “in J. eubulus the iridescent central areas on the upperside [of the wings] are predominantly white with a very faint suffusion of green (particularly evident in the male) or sometimes blue (especially in the female), and the iridescent areas are more extensive, especially on the hind-wing where they extend close to the termen. In J. evagoras, the iridescent central area is blue or pale blue and rarely extends beyond the postmedian area so that the termen is broadly black. The black markings on the underside of J. eubulus [wings] are considerably narrower, and the short black bar at the end of the cell on the upperside of the forewing is narrower or absent. In addition, the underside ground colour is generally paler; the chestnut-brown subterminal band on the underside of both wings is usually richer and more pronounced; and the termen and tornus of the forewing are generally more rounded in J. eubulus than in J. evagoras. The white iridescent area on the upperside [of the wings] is considered to be an autapomorphy for J. eubulus.”

 

2. Jalmenus eubulus is found in Queensland and NSW. In Queensland it is restricted to the seasonally sub-humid central and southern areas of the state. In NSW it is found only in brigalow-dominated open forests and woodlands in northern areas of the state.

 

3. Jalmenus eubulus is an obligate myrmecophile as it requires the presence of ants to complete its life-cycle (Eastwood et al. 2008). Several ant species are recorded tending J. eubulus eggs, larvae and pupae, principally small black species of Iridomyrmex (Eastwood and Fraser 1999; Eastwood et al. 2006).

 

4. Adult Jalmenus eubulus are active from October to April with a peak in flight activity during February and March (Eastwood et al. 2008). J. eubulus is generally univoltine (one generation per year). Local populations emerge from diapausing eggs following summer rains (Eastwood et al. 2008).

 

5. Larvae of Jalmenus eubulus are monophagous, feeding exclusively on the foliage of Acacia harpophylla ranging in height from 0.5–5.0 m (Common and Waterhouse 1981; Pierce and Nash 1999; Braby 2000; Breitfuss and Hill 2003). The larval biology of J. eubulus is very similar to J. evagoras, but differs in that larvae of J. eubulus generally feed alone or in small groups of up to three individuals, and pupate singly on leaves of the larval host plant (Breitfuss and Hill 2003), whereas larvae of J. evagoras are communal, and pupate in groups in silk webbing on the host plant (Common and Waterhouse 1981).

 

6. Jalmenus eubulus breeds only in old-growth forest or woodland and does not appear to colonise regrowth habitats following clearing or other major disturbance (Common and Waterhouse 1972, 1981; Breitfuss and Hill 2003). Suitable habitat is dominated by Acacia harpophylla (Brigalow) and Casuarina cristata (Belah) on clay soils comprising Quaternary alluvial systems or Tertiary clay deposits, on flat to gently undulating plains with poorly developed drainage systems, usually with scattered emergent eucalypts such as Eucalyptus populnea (Poplar Box) and low trees of Geijera parviflora (Wilga) in the understorey (Young et al. 1999). ‘Brigalow within the Brigalow Belt South, Nandewar and Darling Riverine Plains Bioregions’ and ‘Brigalow-Gidgee woodland/shrubland in the Mulga Lands and Darling Riverine Plains Bioregions’ are listed as Endangered Ecological Communities under the Threatened Species Conservation Act 1995. J. eubulus depends on core breeding sites within its habitat and may breed on adjacent trees only when preferred host trees have been defoliated (Eastwood et al. 2008).

 

7. The range of Jalmenus eubulus in NSW has been greatly reduced through the clearing of its brigalow woodlands habitat (Eastwood et al. 2008). Brigalow communities formerly occupied extensive areas of NSW, but much has been cleared for cropping and grazing. For example, Keith (2004) estimated that 60-90% of Brigalow Clay Plain Woodlands had been cleared since European settlement. Much of what remains is fragmented into small (<400 ha) patches occurring between Boggabilla and Moree to the north, and to the west of Narrabri. Pulsford (1984) estimated that less than 0.5% of the original extent of brigalow woodlands were represented within formal conservation reserves, although small fragments have been protected since his review.

 

8. In New South Wales, the species is known only from one location (one site). The area of occupancy is therefore estimated to be approximately 4 km2, based on 2 x 2 km grids, the spatial scale of assessment recommended by IUCN (2008). The geographic distribution of the species in NSW is therefore very highly restricted. The species has not been recorded in NSW for more than 30 years since the observation of two males in April 1977 (DeBaar 1977), suggesting that the population has undergone a continuing decline and may already be extinct in the state.

 

9. Prior to taxonomic revision, Jalmenus eubulus was listed as a Vulnerable subspecies (as J. evagoras eubulus) in Queensland under the Queensland Nature Conservation Amendment Act 1994. Following taxonomic revision, that taxon continues to be listed as Vulnerable in Queensland (Eastwood et al. 2008).

 

10. The combination of the extensive reduction of its habitat, a single known recent population, specialised habitat requirements, the dependence on a single species of host plant, and an obligate relationship with specific ants render this species at extremely high risk of extinction in NSW.

 

11. Jalmenus eubulus Miskin, 1876 is eligible to be listed as a Critically Endangered species as, in the opinion of the Scientific Committee, it is facing an extremely high risk of extinction in New South Wales in the immediate future as determined in accordance with the following criteria as prescribed by the Threatened Species Conservation Regulation 2002:

 

Clause 15

The geographic distribution of the species is estimated or inferred to be:

(a) very highly restricted,

and

(e) the following conditions apply:

(i) the population or habitat is observed or inferred to be severely fragmented;

(ii) all or nearly all mature individuals are observed or inferred to occur within a small number of populations or locations.

 

Clause 16

 

The estimated total number of mature individuals of the species is:

(a) very low,

and

(e) the following conditions apply:

(i) the population or habitat is observed or inferred to be severely fragmented;

(ii) all or nearly all mature individuals are observed or inferred to occur within a small number of populations or locations.

 

Clause 17

The total number of mature individuals of the species is observed, estimated or inferred to be:

(a) extremely low.

 

 

Dr Richard Major

Chairperson

Scientific Committee

Proposed Gazettal date: 11/12/09

Exhibition period: 11/12/09 – 05/02/10

 

References:

 

Braby MF (2000) ‘Butterflies of Australia: Their Identification, Biology and Distribution.’ (CSIRO Publishing: Melbourne, Australia.)

 

Breitfuss MJ, Hill CJ (2003) Field observations on the life history and behaviour of Jalmenus evagoras eubulus Miskin (Lepidoptera: Lycaenidae) in the southern brigalow belt of Queensland. Australian Entomologist 30, 135–138.

 

Common IFB, Waterhouse DF (1972) ‘Butterflies of Australia.’ (Angus and Robertson: Sydney, Australia.)

 

Common IFB, Waterhouse DF (1981) ‘Butterflies of Australia,’ revised edn. (Angus and Robertson: Sydney, Australia.)

 

DeBaar M (1977) New records for butterflies in Queensland and northern New South Wales. Australian Entomological Magazine 4, 11–12.

 

Eastwood R, Fraser AM (1999) Associations between lycaenid butterflies and ants in Australia. Australian Journal of Ecology 24, 503–537. doi: 10.1046/j.1440-169x.1999.01000.x

 

Eastwood R, Pierce NE, Kitching RL, Hughes JM (2006) Do ants enhance diversification in the Lycaenidae (Lepidoptera)? Predictive patterns from the model myrmecophile Jalmenus evagoras. Evolution 60, 315–327.

 

Eastwood R, Braby MF, Schmidt DJ, Hughes JM (2008) Taxonomy, ecology, genetics and conservation status of the pale imperial hairstreak (Jalmenus eubulus) (Lepidoptera : Lycaenidae):a threatened butterfly from the Brigalow Belt, Australia. Invertebrate Systematics 22, 407–423.

 

IUCN (2008) ‘Guidelines for using the IUCN Red List Categories and Criteria. Version 7.0.’ (Standards and Petitions Working Group of the IUCN Species Survival Commission Biodiversity Assessments Sub-committee: Switzerland). (http://intranet.iucn.org/webfiles/doc/SSC/RedList/RedListGuidelines.pdf).

 

Keith DA (2004) ‘Ocean shores to desert dunes: the native vegetation of New South Wales and the ACT.’ NSW Department of Environment and Conservation, Sydney.

 

Pierce NE, Nash DR (1999) The Imperial Blue, Jalmenus evagoras (Lycaenidae). In ‘Monographs on Australian Lepidoptera, 6: Biology of Australian Butterflies’. (Eds R. L. Kitching, E. Scheermeyer, R. E. Jones and N. E. Pierce.) pp. 279–315. (CSIRO Publishing: Melbourne, Australia.)

 

Pulsford I F (1984) Conservation status of brigalow Acacia harpophylla (Mimosaceae) in New South Wales. In ‘The Brigalow Belt of Australia’. (Ed. A. Bailey.) pp. 160–175. (The Royal Society of Queensland: Brisbane, Australia.)

 

Young PAR, Wilson BA, McCosker JC, Fensham RJ, Morgan G, Taylor PM (1999) Brigalow Belt. In ‘The Conservation Status of Queensland’s Bioregional Ecosystems’. (Eds P. S. Sattler and R. D. Williams.) pp. 11/1–11/81. (Environmental Protection Agency: Brisbane, Australia.) 

Page last updated: 28 February 2011