In New Zealand this tropical group of singing insects is represented by one genus, Melampsalta, and they occupy all the available habitats from the coastal rocks and partly fixed dunes, to subalpine scree and rock. M. leptomera, a very thin-bodied, rather drab insect with a very weak song, lives as an adult deep in clumps of marram grass and pingao. M. cruentata, with a red-banded abdomen, green veins on the wings, and a red or pink base to the wings, is reluctant to take flight and is found on fixed dunes and low altitude clearings in the bush throughout New Zealand. Its song is accented in the first note with a long series of unaccented notes following. Although the insect is usually only about 1.4 cm long, material in collections suggests the presence of giant races, almost 1.8 cm long, in several localities. A particular feature of this insect is a very high proportion of males to females. The commonest cicada both in North and in South Islands, M. mudta, is found in open country and is very variable in colour. Its song is shrill and consists of an initial accented note followed by three or four unaccented notes, the whole set repeated continuously. Moderately timid, it usually takes flight on close approach. The colour of the male varies from pale brown, through black-banded deep green, to red brown and nearly black, a yellow or silvery median stripe from the head to the tip of the abdomen being a characteristic feature. The veins of the wings are pale to dark red brown and the base of the wings is buff. The female is invariably much larger than the male, and varies in colour from ochre through pale olive to pale green.
Insects of both sexes usually rest on grass stems but may also be found on herbs and shrubs. On trees and shrubs commonly at the margin of low-level forests in the North Island is a handsome bright-green, hairless insect with two fine black lines outlining the outer margin of a pair of very indistinct olive-green central lozenges on the thorax. This is M. ochrina (1.7 cm) which has a languid, almost lisped song of a long series of unaccented notes. In spite of its softness the song is audible at surprising distances. M. ochrina is slow to take flight but its protective coloration makes it difficult to locate. A highly variable group of green insects of the same size as M. ochrina and larger (1.7–2.5 cm) is represented by cicadas at present classified as subspecies of M. muta, subalpina, and cutora. They are probably members of a separate species. Extreme forms in the South Island approach 2.5 cm in body length. The green body colour is marked by a varying development of black lozenges on the thorax, black bars on the abdomen, and widely varying hairiness. They invariably lack the median silver or yellow stripe on the thorax and head. Its song, like that of ochrina, has a languid tone composed of an initial accented note followed by from two to six unaccented notes. Like ochrina it is found at the lower margins of the forest, but darker and hairier types occur also in the upper alpine scrub. M. cingulata (3.0 cm), New Zealand's largest cicada, commonly gathers on the trunks of trees in large numbers, singing day and night in a deafening chorus that can be heard a quarter of a mile away or more. A feature of the song is a loud wing click. The forewing is strongly angled on the leading edge and there is a black blotch on the forewing, one near the tip and another on the hindwing near the base. The body colour varies from yellow to olive and clear green, with black bars on the abdomen, and four well-developed lozenges on the thorax. The lozenges may be more or less strongly veined with brown.
M. strepitans (North Canterbury, Marlborough, and Wellington) is a smaller (2 cm) relative with similar angle and spotted wings, inhabiting rocky cliffs and river beds. Its body colour is brown, barred with black. The decoration on the thorax differs chiefly in the detail of the central portion of the pattern. Its song is harsh and shrill, without clicks. M. cauta (2.1 cm) is an insect of the trees of lowland forest; its song is harsh and loud and the insect is very timid, taking flight at the approach of possible danger. Its body colour is olive green with silver stripes on the abdomen and spots on the thorax. Both inner and outer lozenges on the thorax are somewhat reduced being replaced by olive brown. This tendency is further developed in M. scutellaris (1.6 cm), a bronze-green species in which the outer lozenges are olive brown with black veins and the inner marked by a black line and central spot. The song of M. scutellaris consists of an equally accented pair of notes monotonously repeated. It is found in tall shrubs, particularly manuka at the forest margin, and can be heard in the tops of the trees of the forest itself. In Auckland and North Auckland the commonest cicada found in open places, and in decreasing numbers further south in the North Island, is M. sericea (1.5 cm) which rests not only on grass but also on shrubs and mud and rock banks and house walls. It is somewhat smaller in size but similar in shape to M. muta but its voice is much louder and its song more diversified in volume and rhythm. The very extensive outer lozenges and the merging central lozenges of the thorax and the dull-brown body colour make the insect appear blackish. There are eight currently identified alpine species of cicadas. These are all very dark and hairy with fat heavy bodies. Only one, M. cassiope, occurs in both islands; the others are confined to the South Island, most with restricted distributions. Recent collecting suggests that this number should be increased.
On the under surface at the rear of the abdomen the female cicada is equipped with a short ovipositor, a spear-like appendage with a flattened diamond-shaped point, used for making elongate slits in the stems and leaves of plants in which the eggs are laid, four or five to a cavity. Some species of cicadas at least are thought to lay several hundred eggs each. Upon hatching, the minute larva escapes from the egg chamber and descends to the ground. In the ground the larvae, which possess a cylindrical proboscis and large claw-like forelegs, grows through several moults. The New Zealand species are believed to feed on the juices of plant roots – few observations, however, have been made. The last stage before emergence of the perfect insect is the formation of a nymph, rather similar to the larva but with rudimentary wings and harder skin. In late spring and summer the nymph emerges from the ground, climbs some distance up bank, grass, stem, or trunk; the skin splits on the back of the thorax and the adult insect emerges with wet crumpled wings and soft skin; the wings dry and harden and the adult insect finally flies away. Although there appears to be some periodicity in the appearance of large numbers of M. cingulata, too little is known of the life history of the New Zealand cicadas to express an opinion on the duration of the life cycle.
by Thomas Ludovic Grant-Taylor, M.SC., New Zealand Geological Survey, Lower Hutt.
- A Revision of the New Zealand Cicadadae (Homoptera) with Descriptions of New Species, Myers, J. G. (Trans. N.Z. Institute (1921), Vol. 53, pp. 238–250)
- Fragments of New Zealand Entomology, Hudson, G. V. (1950)
- Taxonomy, Phyllogeny, and Distribution of New Zealand's Cicadas (Homoptera), Myers, J. G. (Trans. Entomological Soc. of London (1929), Vol. 77, Pt. I, pp. 29–60).