Paralucia pyrodiscus (Rosenstock) (Dull Copper)
Interesting aspects: These small butterflies occur near their foodplants where they are usually seen sunning themselves with opened wings. The common name is appropriate as the butterflies are not very obvious even with wings opened, due to the small areas of orange on the uppersides of the opened wings. They are very similar to their close relative Paralucia aurifera with which they sometimes fly. Both sexes of P. pyrodiscus can be differentiated from P. aurifera in that they lack a series of blue-white subterminal spots at the edge of the hindwing upperside. Female P. pyrodiscus also lack a large orange area on the forewing underside. Males of both species have stubby hindwing tornal tails, which differentiates them from other Australian coppers.
P. pyrodiscus has a rapid flight but of short duration, sometimes reminiscent of skippers. An elusive butterfly, it occurs in well-defined small colonies that can exist for many years if left undisturbed. Males will establish territories in sunny areas within or near the breeding grounds by perching on the hostplants or other low bushes. Females are seen on or close to their hostplants. When settled, the butterflies are easily approached and can sometimes be touched by hand. If startled they fly only a short distance before settling again.
The butterfly has yet to be recorded in South Australia, but a relict population is known to occur in western Victoria near Kiata, 75 km from the S.A.-Vic border, and so it is possible this butterfly may eventually be found in S.A. Butterflies from this area are sometimes known as subspecies lucida Crosby.
Larval food-host: Larvae usually feed on Bursaria spinosa (Christmas bush) (Pittosporaceae) in western Victoria. The larvae eat the leaves and soft new growth of the foodplant.
Larval attendant ant: Larvae are attended by numerous small black ants Notoncus species. In western Victoria the attendant ant is N. ectatommoides, while in central Victoria it is N. capitatus.
Eggs: Small, initially greenish white, later turning greyish white, sub-conical, with a very fine reticulated pattern. The reticulations are trigonal (ordered into hexags), and at each intersection there is a short raised spine. The egg is apically flattened with a depressed micropylar area. Laid singly or in small clusters, usually at the base of the trunk of the hostplant, but sometimes also on leaf litter near the trunk or within the new growing tips of the foodplants. The eggs start to hatch after about 14 days in late spring. Females prefer to lay eggs on small plants below 1.5 m in height.
Larvae: Larvae feed at night accompanied by attendant ants, and hide during the day in cavities made by the ants beneath the ground around the base of the hostplant.
Flight period: In western Victoria the butterfly has a main flight from late October to late December and there is a weak second flight from late February to early April. It overwinters as larvae.
Distribution: The butterfly has yet to be recorded in South Australia, but is known to occur in western Victoria including Kiata, 75 km from the S.A.-Vic border, and so it is possible this butterfly may eventually be found in S.A. as small relict populations. However, surveys for the butterfly have already been undertaken in S.A. without success. The range of the butterfly extends through the coastal and subcoastal areas of south Queensland, NSW and eastern Victoria, but in western Victoria the range shifts inland away from the coast. Inland butterflies from western Victoria are sometimes known as subspecies lucida Crosby and tend to be brighter than the nominotypical subspecies that occurs in subcoastal areas but this difference has also been attributed to thermoregulation.
Habitat: The butterfly has a preference for moist temperate open woodland and open forest. It requires open sunlit areas and the understorey to be open and not overly congested by understorey plants, and has a tolerance for lower rainfall than P. aurifera. The Kiata site has been disturbed historically but appears to be open eucalypt woodland with buloke and similar tall trees, and an understorey containing sporadic developments of very sparse and runty Bursaria. The surrounding area is agricultural land. Similar habitat existed in the Upper Southeast Region of S.A.
Conservation Status: Likely to be extremely rare and localised if found in South Australia. The butterfly is widespread in its range and can still be locally common in NSW if conditions are favourable, but elsewhere known populations are rare or threatened.
Threats: Suitable habitat for this butterfly is now extremely rare in SA. Such prime agricultural habitat was long ago cleared, fragmented and degraded, and turned into farm land. Surviving habitat has been used for grazing with consequent understorey degradation. Bushfires, drought, stock overgrazing and trampling, and the effects of toxic spray drift from adjacent farming properties would likely be the main threats under present conditions.
Conservation Strategy: If colonies of the butterfly were found, then they would need to be monitored to prevent invasion by choking exotic weeds to their habitat, and stock grazing would also have to be closely monitored. Toxic agricultural insecticides and weedicides used in adjacent areas would need to be judiciously applied, particularly those sprays distributed by aerial means. The butterfly should be a good candidate for reintroduction into conserved areas.
Author: R. GRUND, © copyright 10 August 2004, all rights