Ocybadistes walkeri Heron, 1894
Greenish Grass-dart
Don Herbison-Evans
Stella Crossley

Ocybadistes walkeri
(Photo: courtesy of Merlin Crossley, Melbourne, Victoria)

This species was named after the distinguished English insect collector James J. Walker

The Caterpillar has a dark brown head marked with a white wavy band on each side. The body is green. It feeds at night on common grasses (POACEAE), including :

  • False Brome ( Brachypodium distachyon ),
  • Grazing Brome Grass ( Bromus stamineus ),
  • Couch ( Cynodon dactylon ),
  • Panic Veldt Grass ( Ehrharta erecta ),
  • Cogon Grass ( Imperata cylindrica ),
  • Guinea Grass ( Panicum maximum ),
  • Seashore Paspalum ( Paspalum vaginatum ),
  • Kikuyu ( Pennisetum clandestinum ),
  • She-oak Grass ( Spartochloa scirpoidea ),
  • Beach Grass ( Thuarea involuta ),

    and also :

  • Flax Lily ( Dianella species, ASPHODELACEAE ).

    Ocybadistes walkeri
    grass shelter
    (Photo: courtesy of Lyn Loger, Nathalia, Victoria)

    It usually rests by day in a shelter formed from rolled blades of its foodplant, and grows to a length of about 2 cms. To us, the caterpillar was indistinguishable from that of the related species Ocybadistes flavovittatus. Most of these caterpillars we found in Melbourne were Ocybadistes walkeri, and most of them found in Sydney were Ocybadistes flavovittatus.

    Ocybadistes walkeri
    (Photo: courtesy of Ken Harris, Morwell Park, Victoria)

    The adults have dark brown wings with orange markings above. The undersurfaces of the wings have similar markings, but on a greenish yellow background, except for a dark patch along the hind margin of each forewing.

    Ocybadistes walkeri
    (Photo: courtesy of Michael Gordon, Sydney, New South Wales)

    The wingspan is about 2 cms. The dark grey patch on each forewing of the males, and the more convex margin of the female forewing, are the best means of distinguishing the sexes.

    Ocybadistes walkeri
    (Photo: courtesy of CSIRO/BIO Photography Group, Centre for Biodiversity Genomics, University of Guelph)

    The species is easily confused with Ocybadistes flavovittata. The greenish ground colour beneath the wings of the Ocybadistes walkeri distinguishes them.

    Ocybadistes walkeri
    egg, magnified
    (Photo: courtesy of Ken Walker, Mount Lofty, South Australia)

    The eggs of this species are initially white, but turn yellow with red markings as hatching approaches. The eggs are dome-shaped with 16 ribs, and have a diameter of about 1mm. They are laid singly, and attached to the upper surface of a blade of grass by the female butterfly.

    Ocybadistes walkeri
    Mating pair: female on the right, male on the left.
    (Photo: courtesy of Merlin Crossley, Melbourne, Victoria)

    The species occurs in Australia as the subspecies

  • olivia Waterhouse, 1933, in the north of Western Australia and the Northern Territory,
  • sothis Waterhouse, 1933, in Queensland , New South Wales , Victoria , and Tasmania, and
  • hypochlora Lower, 1911, in South Australia.

    Ocybadistes walkeri
    some adults are very fond of golf balls
    (Photo: courtesy of Ted Cadwallader, Swan Hill, Victoria)

    Further reading :

    Michael F. Braby,
    Butterflies of Australia,
    CSIRO Publishing, Melbourne 2000, vol. 1, pp. 204-205.

    Francis Arthur Heron,
    A vist to Damma Island, with notes on the fauna,
    in James J. Walker :
    The Annals and Magazine of Natural History,
    Series 6, Volume 14, Number 79 (1894), p. 106.

    Wesley Jenkinson,
    Life History Notes on the Narrow-brand Grass-dart, Ocybadistes flavovittata flavovittata (Latreille, [1824])
    and the Greenish Grass-dart, Ocybadistes walkeri sothis (Waterhouse 1933) Lepidoptera: Hesperiidae)
    Butterflies and Other Invertebrates Club,
    Metamorphosis Australia,
    Issue 54 (September 2009), pp. 16-20.

    Australian Butterflies
    Australian Moths

    (updated 3 April 2012, 5 January 2024)