Amphipsalta zelandica

Chorus cicada
A chorus cicada, Amphipsalta zelandica
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hemiptera
Suborder:	Auchenorrhyncha
Infraorder:	Cicadomorpha
Superfamily:	Cicadoidea
Family:	Cicadidae
Genus:	Amphipsalta
Species:	A. zelandica
Binomial name
Amphipsalta zelandica (Boisduval, 1835)
Synonyms
Cicada zealandica Walker, 1850 (Lapsus) Cicada zeylandica Walker, 1858 (Lapsus) Cicada zelandica Cicadetta zealandica Melampsalta zelandica Amphipsalta zealandica

The chorus cicada, Amphipsalta zelandica, is the most common species of cicada in New Zealand where it is endemic and found in most areas. They typically live in forests and areas with open bush, where their left-over nymph skins can be seen on tree trunks and branches during the summer months. The males produce their cicada sound in unison, which can reach deafening proportions at the height of their population around February. Groups of cicada can suddenly transition from the typical cicada sound to synchronised clicks, using their wings to clap against the surface they are sitting on.

Description

Amphipsalta zelandica have a nymph stage before their last molt and become an adult. During this nymph stage they are a soft and creamy white,^[1] and very similar looking to the adult form of the chorus cicada. The lengths of the adults are usually larger than 2 cm in length ^[2] while the largest species are up to 4 cm; this includes the wings.^[3] Chorus cicadas’ wing span is about 6 cm and the wings of the chorus cicada only appear after molting to adult stage, they are membranous with veins and they filter out ultraviolet light. The colour of the chorus cicada can be black/green/brown and many have stripes along their body. The antenna of the Amphipsalta zelandica has seven segments with the seventh being constricted medially ^[4] which means the last segment is tightened towards the middle. The adult male cicadas differ to the females by the presence of a clasper sheath, and also the females don’t have finger like extensions which the males do have. The song made by cicadas is the loudest noise made by an insect. Only the male Chorus cicada produces a communication song that is specific to their species. The species can be identified by their song. A pulse group of their song is made up of five clicks where the central click (third click) is stronger than the two on either side of it. The central click can become two clicks if the cicada is tired and has no energy.^[5] These clicks are made by the cicada hitting its wings against the surface it’s sitting on. These pulse groups can be produced quickly and continuously in a prolonged note during chorus sing. It is New Zealand's biggest cicada, their size is averaging around 40 mm.^[6]

Diet and foraging

The adults and immatures of the chorus cicada both feed on xylem sap made from plants, this sap is low in nutrients and doesn’t contain all the necessary amino acids so to make up for this the insects rely on an endosymbiotic bacteria to provide the lacking nutrients from the sap.^[7] This type of food makes the chorus cicada a generalist feeder as it has a range of host plants that it feeds on. An orchard root system provides a good food source the nymphs which live in the soil.

Distribution

Natural global range

Chorus cicadas are endemic insects to New Zealand. The most closely related species are found in Australia, New Caledonia and Norfolk Island. Through study about the New Zealand fauna show that the fauna of New Zealand was from several invasions across the Tasman Sea from Australia or New Caledonia.^[8]

New Zealand range

Chorus cicadas are often found in towns and cities. In addition to central Otago and parts of Canterbury. Chorus cicadas are distributed throughout the whole country.^[9] They distribute in the North Island and some coastal areas of the South Island commonly.

Habitat preferences

Sometimes chorus cicadas are found on buildings, fences or some lamp posts. Cicadas preferred to stay at the eastern coast, in sub-tropical, sub-humid and temperate environments. Chorus cicadas are easily to be seen in open forests and woodlands. Chorus cicadas lay eggs in a herring-bone pattern in the thin branches of tree.^[10] The size of eggs is like a grain of rice. Nymphs crawl up from deep below the soil surface perch and sing. They would sing louder when the weather is warmer. Sometimes, you can watch that two cicadas fight each other. They usually mate on trunk of tree silently.

Cultural uses

The Maori name for cicadas is kihikihi wawa, or matua kihikihi or ngengeti.^[11] The meaning of wawa is ‘to roar like the sound of heavy rain’. One Maori folk song about cicadas name is Tarakihi based on the shrill summer-singing of the tarakihi (cicada), which is an extremely popular haka.

Life cycle/phenology

Adult Cicada has the short life span of two to three weeks. This is because after mating the adult cicada die off.^[7] Mating is triggered by the sound of the males which facilitate the gathering of mass amounts of both sexes. Males compete with each other in terms of producing the loudest and best musical sound. The females lay eggs in either the soil or in the stems of plants (which are split by the female’s ovipositor.^[12] Each Female can lay from 5 to 700 eggs.

The eggs take 3–10 months to develop and hatch. Hatching occurs from May to mid-December.^[13] After hatching the Larvae turn into Nymphs. The larvae bury into the ground therefore they can develop their organs and increase in size. This process and the transformation into Nymphs occurs during the springs and winter months. During this period the Nymphs feed on the juices of roots and other underground organisms. The Nymph stage of the Cicada can last from 25–44 months.

Once the Nymphs have grown to their maximum size they will climb along the tree trunk and out of the ground. This is the transformation turns the Nymphs to adult Cicada. This process occurs on summer nights during the period of mid-December to late February. Once out of the ground the Cicadas wait for their wings to harden before they can fly into the tree trunks.

Predators, parasites, and diseases

The Chorus Cicada has a number of predators but little known parasites. In the adult stage, cicada are killed on birds, Wasps (Such as the Vespula vulgaris), spiders and fungal diseases. In the nymph stage, beetles and also fungal diseases can kill cicada. Parasitic wasps lay eggs into the cicada’s eggs ^[14]

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References

Wikimedia Commons has media related to Amphipsalta zelandica.