Identification of Kikihia species
Genus Kikihia Dugdale, 1972
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| Type species: Kikihia subalpina (Hudson, 1891). | |
Table of contents
Highly diverse yet little known genus
The native genus Kikihia counts 14 described species, including one species (K. convicta) known from Norfolk Island only. In New Zealand, the genus has traditionally been regarded as including three sets of species grouped together by Fleming (1975, 1984) mainly on the basis of habitat preference: the "shade singers" (K. cauta, K. scutellaris), the "green foliage cicadas" (K. cutora, K. dugdalei, K. horologium, K. laneorum, K. ochrina, K. paxillulae, K. subalpina), and the "grass and scrub cicadas" (K. angusta, K. longula, K. muta, K. rosea). These groups are not supported phylogenetically (see Arensburger et al., 2004), i.e. species within each group are not descendants from a single immediate ancestor. Nevertheless, Fleming's groupings provide a convenient way to look at species that are closely similar in external morphology, and quite often also in habits, ecological preferences, and/or acoustic behaviour. Consequently, references will be made to these 'groups of convenience' in later parts of this identification guide.
Although Kikihia may be the most widely distributed and ultimately the most highly diverse of New Zealand cicada genera, with an estimated 28 species (Arensburger et al., 2004), it is currently the least known taxonomically. The shade singers and the grass and scrub cicadas have never been revised taxonomically. Fleming (1973, 1984) reviewed the green foliage cicadas in some depth, but he did not provide an identification key and his morphological descriptions are too incomplete and not sufficiently comparative to allow the writing of such a key at this stage.
Apart from the early taxonomic work of Myers (especially 1929) and Hudson (e.g., 1891, 1950), which are considerably outdated and of limited use for identification, the remaining Kikihia literature mostly deals with hypotheses about the evolutionary history of the genus, speciation mechanisms, acoustic behaviour, and some general biology (see list of references in Arensburger et al., 2004). The catalogue of New Zealand Auchenorrhyncha published by Larivière, Fletcher and Larochelle (2010: Fauna of New Zealand 63) provides a detailed inventory of the fauna, including nomenclature (valid names, synonyms, combinations, and associated bibliographic information), primary type repositories, and information on geographic distribution (including maps), biology and dispersal.
Problems with species identification
Kikihia species identification is highly problematic simply because there exists no identification key to species or sufficiently detailed comparative morphological descriptions to adequately support this process. In addition, the available morphological descriptions are too often biased towards depicting male characteristics and generally accord too much reliability to overall colouration and patterns of dorsal dark markings on head, thorax, and abdomen. The patterns of dark markings are especially unreliable diagnostic characters as they can vary considerably within species and even between sexes. In general, females are paler than males in background colouration and marking patterns; overall colour tends to be yellowish green in usually bright green species or yellowish brown in more darkly coloured ones. Finally, most green Kikihia populations have a small percentage of individuals (about 10%), males or females, with a yellowish orange or reddish background colouration.
Currently, even seasoned cicada enthusiasts agree that identifying Kikihia species involves a lot of guessing work. Much emphasis is put on being familiar with the male call (or song) and on collecting or observing cicadas in locations already known to harbour particular species. Consequently, identifying live male individuals from their song (if one happens to be familiar with it) or live females found mating with such males, in locations known from authoritatively published records to harbour certain species, appears to be the most reliable identification method. Most other ways are tentative and totally dependent on the identifier's level of expertise in the group. For example, the chances of obtaining a correct identification increases as one becomes more familiar with many of the following factors: which species occur in a particular area; their song (applies to males only); their external morphology (although highly variable for many species, with available descriptions most often superficial and biased towards males), and their habitat.
Finally, dentifications are most often required for dead, colour-faded, and not necessarily male specimens, or, live individuals collected or observed in locations so far unrecorded for Kikihia species, and specimens generally not supported by detailed geographic or biological information. These very common situations leave most people, nature enthusiasts as well as trained entomologists, at a dead-end in terms of their ability to identify Kikihia individuals to species level.
Solutions for species identification
What is urgently needed is a comprehensive revision of the genus Kikihia, one that would include detailed morphological descriptions that are comparative between species and characters such as the genitalia (both sexes), tymbals, opercula, etc. Such revision would also attempt to correlate information from morphological, ecological, behavioural (including acoustic behaviour), and molecular studies. Only then would it be possible to prepare a reliable identification tool based on morphology and to offer a more holistic understanding of this genus. Unfortunately, study datasets (morphological, molecular or otherwise) are too often developed or used in isolation from each other. So far, too much emphasis may have been put on acoustic behaviour at the expense of thorough morphological investigation, and molecular studies have primarily been correlated to geographic and acoustic data, hardly ever to morphological attributes.
In the meantime, it should be possible to increase access to species-level diagnostic information contained in the literature and in New Zealand insect collections, at least for described species, by bringing this information together on the present website and rendering it more palatable to non-specialists while retaining its usability for trained entomologists and cicada specialists.
Hopefully, the following preliminary identification aids (image gallery, location guide, factsheets) will go some way to achieve these goals.
Preliminary identification aids and how to use them
Browsing through the image gallery can offer some initial guidance; a limited number of species are readily recognisable by their overall external appearance. However, the most logical way for end-users to go about their identification is by first using the location guide where they will be able to click on the area(s) where specimens were collected or individuals observed. This will yield a result page listing possible species to be identified with hyperlinks to images and factsheets that describe species in more detail, diagnose them against closely similar species, and provide additional information (e.g., range, habitat) and, when appropriate, hyperlinks to other websites (e.g., containing additional images, song files, etc.).
A higher level of confidence in the final identification may be reached if the location guide, the image gallery, and the species factsheets are used in combination.
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Image gallery |  |
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Location guide |  |
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KIKIHIA SPECIES FACTSHEETS |
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| Shade singers |  |
Green foliage cicadas |  |
Grass and scrub cicadas |
| K. cauta-scutellaris | K. dugdalei-ochrina | K. angusta-longula-muta-rosea | ||
| K. horologium-laneorum-subalpina | ||||
| K. cutora-paxillulae | ||||
Note about the location guide. End-users may find it useful to click on area(s) neighbouring the target area they are after in the location guide. This may yield additional species recorded in adjacent areas and that can potentially be found in the target area; areas of New Zealand have been unequally surveyed for cicadas and a number of areas have not yet been recorded for described species.
Note about factsheets. Each factsheet includes more than one species, i.e. species that are most closely similar morphologically but not necessarily closely related phylogenetically, i.e., not necessarily descendants from a single immediate ancestor. The geographic areas listed in the range of each species follow Crosby et al. (1976, 1998).