Didymuria violescens (Leach, 1814)


Male, after Leach, 1814

Common Name:

Violet-winged stick insect
Spur-legged stick insect

Identification:

Green, with the external edge of the elytra yellowish; the wings, with the exception of the coriaceous margin, purplish; the four hinder thighs spiny beneath. May be readily distinguished by the colour of the wings, and by the long tooth under the middle part of the hinder thighs. (Leach, 1814)


Campbell & Hadlington, 1967
Male: The male is fully winged, has inflated hind femora bearing two or three large black spines ventrally (from Key, 1991)


Campbell & Hadlington, 1967
Female: The female is shorter-winged and flightless, with the hind femora unspecialised. (from Key, 1991)

The costal area is yellowish green tinged with brown; the anterior margin bright yellow, with the outer ridge white; the tegmina are similar to the latter in colour and markings: but the most remarkable character which this insect possesses, is the immense strength and thickness of the hind thighs, though of a moderate length in comparison with the size of the insect; they are also armed with three strong, long, black spines, situated beneath, the one near the base is smaller than the other two; they are also strongly dentated, with elevated longitudinal lines on the upper surface, and are of a reddish yellow; the head is small without any stemmata; the mesothorax is rather long, narrow, but wider at the base, and is brownish yellow, covered with minute tubercles; the abdomen is reddish violet, with the tip green, but the leaflets are reddish violet; the four fore-legs are green, with the thighs of the intermediate pair dentated. (from Gray, 1833)

Lifesspan: nymphs take 4 months to mature, the adult stage a further 2 months.


Key, 1994

Campbell & Hadlington, 1967
The mature female oviposits during late summer and autumn. The eggs hatch when the average temperature rises, which is usually from November to December. Nymphal development is usually complete by the end of March, five (male) or six (female) nymphal instars. Eggs from unmated females yielded female individuals only, and thus the parthenogenesis appears to be thelytokous (however it is rare, 0.6%). (from Campbell & Hadlington, 1967)

Habitat:

Arborial, top of host splants (not necessarily top of canopy).

Most of the Eucalyptus species are acceptable as food, though there are preferences within the genus. While no quantitative tests have been done on food preferences it has been noted in nature that the narrow-leaved “peppermints” E. radiata Sieb. and E. robersoni Blakely, the broad-leaved “peppermint” E. dives Schauer and the “gums” E. viminalis Labill., E. huberiana Naud., E. dairympleana Maiden, E. mannifera (A. Cunn. Herb.) Mudie, E. stellulata Sieb., E. pauciflora Sieb., and E. bicostata Maiden, Blakely and Simmonds appear to be favoured species, and are the first to be defoliated. Other species which are known to have been severely defoliated are E. laevopinea R. T. Baker, E. obliqua L'Hérit., E. delegatensis, R. T. Baker, and E. fastigata Deane and Maiden, though these appear to be less favoured than the former groups. E. andreana Naud. is an acceptable species and has been used for most laboratory rearings. Some Eucalyptus species are avoided and these will only be eaten when there is no choice of food. (from Campbell & Hadlington, 1967)

Similar Species:

Rearing Notes:

Forrestry Commision of N.S.W reared this specied for many years while studying it.

Parthenogenic eggs give rise to male stick-insects in the next generation, thus increasing the chance that the females of that generation will be mated normally. (Hughes, 1975)

For a stick insect with body length 62mm, to keep 2 adult females, you need a cage at least 300mm high, 140mm deep and 140mm wide.

Range:

Dense populations of both these species of phasmatids have been recorded only from highland (above 2,000 ft) forest areas of southeastern Australia, though occasional insects are found at low altitudes and near the coast. (from Campbell & Hadlington, 1967)

This insect has a widespread distribution throughout the forested areas of southeastern Australia, mainly in the highland region and occasionally in the coastal region.

NE coastal, SE coastal, Murray-Darling basin, Gulfs, QLD, NSW, VIC, TAS, SA, Lord Howe Is.

Status:

Not endangered. Know to occur in plague proportions from time to time.

References

Synonyms:

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