Zizina otis

Zizina otis Fabricius, 1757
Common Grass Blue
(often known as Zizina labradus)
POLYOMMATINI, POLYOMMATINAE, LYCAENIDAE, PAPILIONOIDEA

Don Herbison-Evans
(donherbisonevans@yahoo.com)
and
Stella Crossley

Zizina otis
(Photo courtesy of Harold McQueen, Goodna, Queensland)

These caterpillars are green slug-like creatures, with short pale hairs, and a dark green stripe along the back, and a thin yellowish stripe along each side of the body. The head is brown or black, although it normally cannot be seen, as the caterpillar holds it tucked under the thorax.

(Photo courtesy of Harold McQueen, Goodna, Queensland)

The caterpillars rest by day at the base of the foodplant, and feed nocturnally on various members of FABACEAE, such as:

Emu Foot ( Cullen tenax ),

Australian Indigo ( Indigofera australis ),

Lucerne ( Medicago sativa ),

Glycine ( Neonotonia wightii ),

Romano Beans ( Phaseolus coccineus ),

Garden Peas ( Pisum sativum ), and

Clover ( Trifolium species).

oops: the girdle broke
(Photo courtesy of Harold McQueen, Goodna, Queensland)

The caterpillars grow to a length of 1 cm. The pupa is dirty pink, pale green, or pale yellow, with variable dark markings. The pupa is attached to a convenient surface by cremaster and girdle. The pupa has a length of about 1 cm.

female
(Photo: courtesy of Edwin Vella, Yarramundi, New South Wales)

The female adult has a black body, and the upper surfaces of the wings are dark brown, with a purplish blue sheen around the bases.

male
(Specimen: courtesy of the Macleay Museum, University of Sydney)

The male adult has a black body, and the upper surfaces of the wings are purplish blue except for a black edge to each margin.

close-up, showing white spot on the antenna club
(Photo: courtesy of Harold McQueen, Goodna, Queensland)

The butterflies have an interesting white spot on the club of the antenna. They normally fly very close to the ground. The undersides are greyish blue with a fawn pattern of spots and stripes.

egg, magnified
(Photo: courtesy of Ken Walker, Melbourne, Victoria)

The bluish toroidal eggs are laid singly on the leaves of a foodplant. Each egg is covered in a microscopic triangular network of white ribs. The eggs each have a diameter of about 0.5 mm. In summer in Melbourne, eggs that we collected hatched in three days from being laid.

mating pair
(Photo: courtesy of Tony Rodd)

The species is found as a number of subspecies over most of Africa, Asia, and the Pacific, including:

Democratic Republic of the Congo,

as well as in Australia in :

South Australia, and

The subspecies labdalon Waterhouse & Lyell, 1914, occurs on

Cape York.

underside
(Photo: courtesy of Trevor Jinks, North Burnett, Queensland)

There are controversies whether all the occurrences in Australasia are of Zizina otis labdalon, and whether Zizina labdalon is a separate species.