FNZ 50 - Heteroptera (Insecta: Hemiptera) catalogue - Introduction
Larivière, M-C; Larochelle, A 2004. Heteroptera (Insecta: Hemiptera): catalogue. Fauna of New Zealand 50, 330 pages.
(
ISSN 0111-5383 (print),
;
no.
50.
ISBN 0-478-09358-6 (print),
).
Published 14 May 2004
ZooBank: http://zoobank.org/References/A7CCCF4B-BAEA-4515-AE1A-740523FD1289
Introduction
The Heteroptera, or true bugs, are the largest and most diverse group of hemimetabolous insects. They are here treated, as is generally accepted, as a suborder of the Hemiptera. There may be some 37,000 described species of Heteroptera worldwide and possibly another 25,000 species remaining to be described (Schaefer & Panizzi 2000).
True bugs are a highly adaptable group that has managed to occupy most terrestrial as well as many aquatic and semi-aquatic habitats, and to adopt remarkably diverse life habits, on nearly all continents and most islands, suggesting a long evolutionary history for the group.
The world fauna comprises approximately 75 families. The number of species of better known continental faunas such as North America, Europe, or Australia, may be around 2,000 or 5,000 species. Compared with these larger regions of the world the New Zealand fauna, currently comprising 29 families, 136 genera, and 305 species, may appear relatively small, but what it lacks in size it makes up in uniqueness, e.g., 82% of known species are endemic. From this point of view New Zealand can be regarded as a biodiversity "hot spot" for this group.
True bugs have been collected extensively in New Zealand and are well represented in entomological museums and collections. Despite this, no up-to-date catalogue has been published following Wise's (1977) “ ... synonymic checklist of the Hexapoda of the New Zealand sub-region ...” which enumerated 100 genera and 170 species. Numerous nomenclatural changes and new taxa have been published since then and although the aforementioned checklist is still useful, it no longer reflects the current knowledge of the fauna.
The present catalogue attempts to answer the four questions most commonly asked about a group of insects by users of biosystematics information: What, where, when, and how? What Heteroptera occur in New Zealand, what is their status (e.g., endemic, native but not endemic, adventive, pests, beneficial predators), and what are the resources available to identify and study them? Where do species and genera occur (e.g., geographic distribution in New Zealand and overseas, habitats, dispersal abilities)? When are they active (e.g., seasonality, mating, oviposition, overwintering)? How do they live (e.g., food preferences, natural enemies)?
To answer these questions, the present catalogue brings together the available literature and collection-based information on extant taxa recorded from New Zealand's main islands and its offshore islands. It has been written with the needs of biosystematists, identifiers, biosecurity and conservation managers, ecologists, other biologists, and members of the public in mind, hence the sections summarising for all species the geographic distribution, biology, dispersal power, and the citation of main references to available identification tools, taxonomic revisions, and natural history treatments. A species checklist, a full bibliography, a taxonomic index, several appendices, species distributions maps, and primary type photographs are also provided.
All attempts have been made to report information as accurately as possible, but none are more aware than the authors of the inevitability of errors or omissions in this type of work. Therefore, the authors ask the indulgence of readers and can only hope that the usefulness of this catalogue will outweigh any shortcomings.
Brief history of Heteroptera taxonomy in New Zealand.
The first member of the Heteroptera described from New Zealand was the acanthosomatid Oncacontias vittatus (Fabricius, 1781). Subsequently, until the 1930s, the majority of taxa were described by European workers, especially White (1876-1879) and Bergroth (1918-1927).
Several early attempts at cataloguing the fauna were made during that same period, especially by Butler (1874), Hutton (1874, 1898, 1904), White (1878-1879), Kirkaldy (1909a), and Myers & China (1928). Such early checklists were most often straightforward compilations, but Hutton's (1904) Index Faunae Novae Zealandiae was probably the most comprehensive and well documented, although his 1898 checklist was also very useful because it included keys to most known genera. Kirkaldy's (1909a) List of the Hemiptera (excluding Sternorrhyncha) of the Māorian Subregion, with Notes on a Few of the Species was largely based on Hutton (1904), with a few additional critical comments such as new synonymies or deletions from the fauna.
In 1928, Myers & China provided a more critical inventory of the fauna by reviewing earlier checklists, recording subsequent nomenclatural changes and newly described taxa, and by listing species according to three faunal categories (indigenous, introduced, and erroneously recorded or strongly needing confirmation). Myers & China's work would be long-standing as there would not be another comprehensive faunal list until the publication of A synonymic checklist of the Hexapoda of the New Zealand sub-region, the smaller orders by Wise in 1977. The latter recorded 22 families, 100 genera, and 170 species for the fauna, together with their synonyms, nomenclatural combinations, associated references, and basic distributional information. The majority of taxonomic changes that followed Wise (1977) have been reported by Larivière (1997, 2002), and the New Zealand checklist is continually being updated and made available on the internet (see Larivière, 2002a, http://www.landcareresearch.co.nz, New Zealand Hemiptera website).
The period from 1950 to 1970 yielded several new taxa and important taxonomic revisions, mainly due to the efforts of Woodward (especially 1950, 1953, 1954, 1956) and Usinger & Matsuda (1959). These workers described over 20 genera and 45 species in several families, and provided good keys and very detailed taxonomic descriptions. In addition, various other workers described individual taxa from a range of families which meant that by the end of the 1960s there were twice as many taxa known as had been listed in Myers & China's (1928) checklist. Eyles (1970a) reported 89 genera and 148 species for the fauna, but he did not provide an updated checklist.
Much of the taxonomic effort between 1970 and 1977 went into the family Lygaeidae sensu lato (Artheneidae, Cymidae, Heterogastridae, Lygaeidae, Rhyparochromidae, in this catalogue) . The solid contributions of Malipatil (especially 1976-1979), particularly on the tribe Targaremini, deserve special mention.
The most active period of taxonomic work, however, was still to come. The last 25 years or so have seen the description of more than 100 new species and several new genera. Most of this represents the highly prolific work of one New Zealander, A. C. Eyles, especially on the families Lygaeidae and Miridae (e.g., Eyles, 1990-2003 and collaborations with overseas workers).
In addition to the sharp increase in the number of described taxa in recent years, the Australasian and world heteropterological scene has also substantially changed. Most of these historical developments have been summarised by Schuh & Slater (1995: True Bugs of the World ).
For example, the last 25 years have seen the publication of modern catalogues (e.g., Froeschner 1981, Heteroptera of Ecuador; Kormilev & Froeschner 1987, world Aradidae; Henry & Froeschner 1988, Nearctic Heteroptera; Maldonado-Capriles 1990, world Reduviidae; Aukema & Rieger 1995-2001, Palearctic Heteroptera; Cassis & Gross 1995 and 2002, Heteroptera of Australia; Schuh 1995, world Miridae; Slater & O'Donnell 1995, world Lygaeidae sensu lato; Henry & Froeschne, 1998, world Berytidae; Froeschner 1999, Heteroptera of Panama; Maw et al. 2000, Heteroptera of Canada), electronic lists (e.g., The True Bugs of South Africa website by Villet; Australian Biodiversity Information Facility), world revisions and treatments on higher classification (e.g., Henry 1997a-b Pentatomomorpha and Berytidae), and Hemiptera phylogeny (e.g., Schaefer, 1996a), and other advances in heteropterology.
These scientific developments have resulted in significant contextual changes in which to consider the New Zealand fauna and, together with the urgent need to catalogue taxonomic changes and new descriptions since 1977, provided much of the impetus for preparing the present catalogue.
As far as comprehensive taxonomic revisions are concerned - those including all available nomenclatural data, examination of all types, and detailed comparative study of male genitalia and other morphological features across and within all known populations - these currently cover approximately 160 species or about 50% of the described fauna. Consequently, apart from the Miridae, Lygaeidae, Pentatomoidea, and part of the Rhyparochromidae, all other families (at least 20) occurring in New Zealand are in great need of modern revisionary treatment.
Furthermore, so much new material has been collected and deposited in New Zealand collections in the last 25 years - one of the most dynamic insect surveying periods in New Zealand - that numerous new taxa remain to be described even in families worked on by previous researchers. The authors estimate that the fauna may reach 400 to 500 species when totally described.
Potential revisers of the fauna may find it useful to note that over 65% of primary types of New Zealand Heteroptera (see type photographs, pp. 225-275) have been deposited in this country's entomological museums and collections (see Early & Gilbert 1993; Larivière 2000 and 2002b; Larivière & Rhode 2002; Nicholls et al . 1998; Palma et al. 1989). Approximately 15% of types can also be located in the Museum of Natural History (London), which leaves around 20% of types scattered among other overseas collections. The high proportion of primarily local or readily accessible type repositories means that specimens can be more easily studied, making the process of revising taxa much easier in Heteroptera than in many other insect groups with most New Zealand types scattered through several overseas collections. "Virtual collections" of New Zealand types are being made available on the internet (see Larivière & Rhode 2002, http://www.landcareresearch.co.nz, New Zealand Hemiptera website).
Taxonomic works published until now generally deal with the adult stage. Less than 15% of described New Zealand Heteroptera have had immature stages described. Among all families, only the last instar nymphs of Acanthosomatidae, Cydnidae, and Pentatomidae have been better documented, together with a few species of the superfamily Enicocephaloidea and the families Lygaeidae, Miridae, Rhyparochromidae, and Veliidae.
Identification keys are also few. The most up-to-date keys to identify New Zealand Heteroptera at the family level are The Insects of Australia , Chapter 26. Hemiptera (Carver et al . 1991) and A key to the bugs of Australia (Elliott & Cassis 2001; LUCID key, http://www.faunanet.gov.au/).
Below the family level, identification is problematic and one has to rely mostly on original taxonomic descriptions, when available, and apart from some recent works that include keys to taxa of Lygaeidae, Miridae, Pentatomoidea, and Rhyparochromidae, the literature is scattered. In addition, Eyles (2000b) provided an overview of introduced Mirinae and Deitz (1979) published a very useful paper listing selected references for identifying New Zealand Hemiptera. Much of Deitz's information on Heteroptera has been included and updated here with bibliographic resources listed under the appropriate taxa in the catalogue.
The authors are preparing keys to Heteroptera so far recorded from New Zealand. Electronic versions of these keys will be made available on the internet (http://www.landcareresearch.co.nz, New Zealand Hemiptera website), and printed in the Fauna of New Zealand series.
Higher classification.
The historical developments leading to the current higher classification of Heteroptera have been well summarised by Schuh & Slater (1995) for the world, and by Cassis & Gross (1995, 2002) for Australia and neighbouring areas.
The higher classification used in the present catalogue (Table 1) is based on Cassis & Gross (1995, 2002). In particular, this involves the adoption of Henry's (1997a) classification for the Lygaeoidea which, as far as New Zealand is concerned, gives family rank to the Artheneidae and restores the family status of the Cymidae, Heterogastridae, and Rhyparochromidae. In addition Lis' (1999) proposed higher classification for the Tingoidea is adopted, resulting into the classification of New Zealand taxa into two families (Tingidae and Cantacaderidae).
On a world basis, there may be more agreement on the phylogenetic classification of infraorders, superfamilies, and families of Heteroptera (represented in Table 1) than on the classification of suprageneric taxa within families.
The following references are the main sources of information on infraordinal and superfamilial classification in general, and on existing alternative arrangements to the ones adopted here: China & Miller (1959, world families); Stys & Kerzhner (1975, classification for whole suborder, full synonymical list for higher taxa); Schuh (1986b, review of infraorders and their included families, morphological cladistics); Slater (1982, descriptions of superfamilies); Stys (1985, additional categories and sister-group relationships of infraorders); Stys & Jansson (1988, classification of Nepomorpha); Schuh & Stys (1991, phylogeny of Cimicomorpha); Schaeffer (1993, outline of Pentatomomorpha systematics); Wheeler et al . (1993, morphological and molecular cladistics of higher taxa); Henry (1997a, phylogeny of Pentatomomorpha, especially Lygaeoidea), and Lis (1999, phylogeny of Tingoidea).
The subfamilial and tribal classifications used in the present catalogue also follow Cassis & Gross (1995, 2002) who provided overviews of existing alternative classifications for a number of families. The reference section under each family in the present catalogue gives the major reference sources dealing with family-group classification on a world basis.
Geographic distribution.
The New Zealand fauna is highly insular, with 40% of genera and 82% of species presently recorded as being endemic (Table 2).
The maps on pages 283-318 summarise the geographic distribution of Heteroptera taxa (species and subspecies) occurring in New Zealand, based on the areas and codes of Crosby et al. (1976, 1998). This catalogue is the first attempt at presenting a synopsis of species distributions across all families of Heteroptera for New Zealand, based on information scattered through entomological collections as well as the literature. Consequently, most species now appear to be more widely distributed than originally perceived in the literature; even reputedly well-studied species have been shown to occur in more areas of New Zealand. Nevertheless, roughly 130 taxa (42% of the total fauna) are currently known from 10 populations or fewer, and many of these species are known from the type locality only.
A greater number of taxa (224) occurs on the South Island, although 79 native species are actually restricted to it. A slightly lower number of taxa (206) occurs on the North Island, including 61 native species restricted to this island. As many as 137 taxa are shared between the North and the South Island.
Patterns of taxonomic diversity and the number of taxa restricted or endemic to areas of New Zealand are illustrated on Maps 4-7 (pp. 279-282). The areas so far known to contain the highest diversity are (from north to south): ND (123: 84 endemics, 16 other natives, 23 adventives), AK (124: 80 endemics, 18 other natives, 26 adventives), WN (109: 84 endemics, 13 other natives, 12 adventives), NN (147: 114 endemics, 14 other natives, 19 adventives), and MC (111: 87 endemics, 7 other natives, 17 adventives).
Several native species are restricted or endemic to a single area (Map 6, p. 281). Currently, the areas known to have the greatest number of such taxa are: ND (10), WN (4), NN (5), and FD (8). Most Heteroptera families found in New Zealand include taxa that are primarily forest-dwellers and these areas have relatively large remnants of native bush.
The areas that include the largest number of adventive taxa (Map 7, p. 282) are: North Island - ND (23), AK (26), GB (18), BP (16); South Island - NN (19), MC (17). Generally, these are the warmest areas of New Zealand as well as its main trading ports or agricultural regions. Many of the adventive taxa are also known to fly to artificial lights on warm nights.
Finally, no true bugs have been recorded from the Antipodes Islands, Bounty Islands, Campbell Island, and Snares Islands.
Faunal composition and affinities.
Cassis & Gross (1995, 2002) and Schuh & Slater (1995) published up-to-date faunal overviews for Australia and the world respectively. Larivière (1997) provided a preliminary analysis of the composition and affinities of New Zealand Heteroptera based on generic and suprageneric data. Parts of this treatment are updated and expanded here.
Table 2 shows the number of genera and species occurring in New Zealand compared to Australia and the rest of the world. Table 3 provides a more detailed overview of the New Zealand fauna, by families and genera. The New Zealand fauna (305 species) is about 14% the size of the Australian fauna which, according to Cassis & Gross (1995 & 2002), is around 2,100 species. Currently, thirty-eight (38) families occurring in Australia are not represented in New Zealand.
The number of recognised adventive species in New Zealand is currently thirty-three (33) or about 11% of the total fauna. No family of Heteroptera is endemic to New Zealand, but all eight (8) subfamilies of world Aradidae are represented. The native Heteroptera fauna is characterised by a large proportion of ground-dwelling or litter-inhabiting species, and 25% of species are flightless (approximately 65% of Aradidae and 70% of Rhyparochromidae). The largest Heteroptera families in New Zealand are the Miridae (115 species or 38% of the fauna), Rhyparochromidae (42 species or 15%), Aradidae (39 species or 14%), and Lygaeidae (33 species or 11%). In Australia, the four largest families are the Pentatomidae (363 species or 17%), Reduviidae (226 species or 11%), Miridae (186 species or 9%), and Rhyparochromidae (185 species or 9%), but these numbers will change as large portions of the Australian fauna are still unrevised. The Tingidae sensu lato (147 species) and Aradidae (143 species) are also well represented in Australia. The largest Heteroptera genus in New Zealand is Chinamiris (Miridae, 31 species). Many (over 30) unrevised Heteroptera genera are currently represented by a single species in New Zealand.
Most taxa shared with Australia and other parts of the world are cosmopolitan and probably introduced, except those listed in Table 4, with distribution ranges including southern Australia, Tasmania, New Zealand, and in three instances southern Chile, and for which a Gondwanan origin is more likely.
In Acanthosomatidae, the subfamilies Ditomotarsinae and Blaudusinae are dominated by elements from the southern landmasses of southern Africa, Chile, and Australia. These subfamilies are not represented in New Zealand, although Rhopalimorpha (Acanthosomatinae) is found in this country and southern Australia, while Oncacontias is restricted to New Zealand. The nature of the relationship between Rhopalimorpha and other acanthosomatine genera is unclear. Southwood & Leston (1959) hypothesized that this old austral lineage has "revived" in the Oriental and Palearctic regions during the Tertiary. This, however, remains to be tested cladistically.
The New Zealand and southern Pacific Enicocephalo-morpha are diverse and include a number of typically austral taxa. In the Aenictopecheidae, the tribe Nymphocorini comprises only Nymphocoris , with two species, one from New Zealand and one from Tasmania. In the Enicocephalidae, the subfamily Phthirocorinae includes two tribes from the southwest Pacific and the subantarctic islands. The Phthirocorini include four genera, two of which are monobasic and endemic to New Zealand ( Gourlayocoris , North and South Islands; Phthirostenus , South Island and Auckland Islands).
Nearly half of all Aradidae occur in the Oriental-Pacific area. Degrees of generic endemism vary throughout this region, reaching a peak in the old land masses of Australia, New Zealand, New Caledonia, and mainland Asia (Monteith, 1982). All eight subfamilies are represented in New Zealand and Australia. The Chinamyersiinae are restricted to the south-west Pacific, and the Isoderminae and Prosympiestinae have a classic east Gondwana distribution in Chile, New Zealand, and south-east Australia.
In the Corixidae, the subfamily Diaprepocorinae contains only Diaprepocoris which is restricted to Australia and New Zealand.
As in many other parts of the world the family Rhyparochromidae is taxonomically diverse. The main faunal relationships with other parts of the Southern Hemisphere are in the tribes Drymini (Brentiscerus), Lethaeini (Paramyocara), Myodochini (Remaudiereana), Rhyparochromini (Stizocephalus), Targaremini (Geratarma ), and Udeocorini (Udeocoris). New Zealand shares only one genus of Targaremini (Geratarma) with Australia. Extensive radiation of the Targaremini has, however, occurred in New Zealand, which has nine (9) endemic genera representing about 40% of the world genera. All but 3 genera of Targaremini have a typical southwest Pacific distribution (Eyles 1967). The tribe is known from 23 genera and 57 species found in Australia, New Guinea, New Caledonia, Vanuatu, and New Zealand (Slater 1986; Slater & O'Donnell 1995). They appear to be an ancient group, probably of New Zealand-Australian origin, and occur in mesic forests (including Nothofagus) on both sides of the Tasman sea.
In the Miridae, the genus Chaetedus is known from four species in New Zealand, Australia, and New Guinea. Chaetedus longiceps is shared by New Zealand, continental Australia, and Tasmania. Chaetedus plumalis is known from the Kermadec Islands and Norfolk Island.
Two genera of Tingidae sensu lato (Cantacaderidae and Tingidae in this catalogue) are shared with other areas of the Southern Hemisphere. The genus Carldrakeana belongs to the primarily austral family Cantacaderidae, which includes at least another 19 genera. Tanybyrsa belongs to the cosmopolitan subfamily Tinginae of the Tingidae.
At the generic level New Zealand shares with Australia about 10% of its native fauna. At the species level, this is approximately 5%. Most faunal relationships are of a trans-Tasman nature. The composition of the shared fauna has not varied much over the past several decades to 100 years, which may suggest that overseas dispersal may not have made a major contribution to the New Zealand fauna.
As for the island groups in the Tasman Sea between Australia and New Zealand, only Norfolk Island has one taxon (Lissaptera, Aradidae) with solely a New Zealand relationship. Close relationships are not shown with New Caledonia; the few generic and subgeneric affinities documented in Table 4 may or may not represent natural distributions, except perhaps for Aradus australis (Aradidae). Most taxa recorded from the Kermadecs are either adventive, widely distributed in the subtropical South Pacific, or (sometimes) shared with New Zealand and Australia. Not one species has a sole relationship with New Zealand. Only one species (Diomocoris raoulensis, Miridae) is currently recorded as being endemic to the Kermadec Islands.
Biology and dispersal.
Schuh & Slater (1995) and Wheeler (2001) provided up-to-date overviews on the biology of world Heteroptera and Miridae, respectively.
The majority of Heteroptera families occurring in New Zealand are terrestrial. Some families are semiaquatic (Gerridae, Hydrometridae, Saldidae, Veliidae) or aquatic (Corixidae, Notonectidae), but these represent only 20 species or so (less than 7% of the fauna). Lentic habitats are not a major feature of the New Zealand environment and the majority of lakes and ponds are of volcanic or of relatively recent glacial origin.
The Mesoveliidae include one native taxon Mniovelia kuscheli which is terrestrial, and one (probably adventive) taxon, Mesovelia hackeri , recorded here for the first time for New Zealand, which is semiaquatic. There are no freshwater waterstriders (Gerridae) recorded from New Zealand; the only gerrid species occurring in this country's territorial waters is the oceanic species Halobates sericeus .
The introduced representative of the Cimicidae (Cimex lectularius, the bed bug) is a well known cosmopolitan mammal ectoparasite.
Terrestrial species can be either predominantly epigean (e.g., Enicocephaloidea, Aradidae, Rhyparochromidae), planticolous (e.g., Anthocoridae, most Miridae, Reduviidae, Pentatomidae, Tingidae sensu lato), or arboreal (most Deraeocorinae, Chinamiris species, many Bipuncticorisspecies (Miridae)). The Lygaeidae are an epigean group, except for the genus Rhypodes which has most species living both on the ground and on plants, and at least three species living on trees. The Rhyparochromidae are also predominantly epigean, but a number of species live on the ground as well as on plants and trees (e.g., Paramyocara, Remaudiereana, Woodwardiana evagorata, Metagerra helmsi, Metagerra obscura, Targarema electa). The endemic rhyparochromid Margareta dominica lives strictly on sedge (Gahnia spp.). A number of families include corticolous species (e.g., Anthocoridae, many Aradidae, Enicocephalidae, and the endemic cylapine Peritropis aotearoae (Miridae)).
The two native habitats harbouring the greatest number of species are forests and shrublands (in the lowlands and on mountains). Tussock grasslands and open subalpine environments also harbour their own special suites of taxa (e.g., Kiwimiris (Miridae) or Rhypodes (Lygaeidae) species). In general, native species tend to live within the confines of native habitats, but many species also survive in modified environments. Adventive species seem to be able to invade natural habitats but, in general, only to a slight degree. Closterotomus norwegicus, Stenotus binotatus, Halticus minutus, Lopus decolor (Miridae), Nabis kinbergii (Nabidae), Cuspicona simplex, Dictyotus caenosus, and Nezara viridula (Pentatomidae) are notable exceptions with wide-ranging distributions across all kinds of habitats from sea level to high elevations. On the other hand, some native species also dwell successfully in exotic or highly modified ecosystems. Some of the most commonly encountered examples are: Oncacontias vittatus (Acanthosomatidae), Ctenoneurus hochstetteri (Aradidae), some Rhypodes species (Lygaeidae), Cermatulus nasalis nasalis , Oechalia schellenbergii (Pentatomidae), and Targarema stali (Rhyparochromidae), in exotic forests; Rhopalimorpha lineolaris and R. obscura (Acantho-somatidae), Cymus novaezelandiae (Cymidae), Deraeocoris maoricus , Lincolnia lucernina (Miridae), in pastures; Chaetedus longiceps , some Diomocoris species, Romna scotti , Sejanus albisignatus (Miridae), in cultivated fields; and Nysius huttoni (Lygaeidae) in grassy habitats.
Very few native species live almost exclusively in coastal lowlands. Some species more characteristic of these areas are: Clavaptera ornata , Modicarventus wisei (Aradidae), Chilocoris neozealandicus (Cydnidae), Chinamiris aurantiacus (Miridae), in coastal lowland forests and shrublands; Chaetedus longiceps (Miridae), in coastal grassy habitats; and many Saldidae (some undescribed), in intertidal habitats in estuaries. On the other hand, most coastal sand dunes, estuarine habitats, and coastal wetlands are typically inhabited by adventive species; these habitats are of relatively recent origin (Quaternary era) in New Zealand.
Most New Zealand families, however, are characterised by a majority of lowland-montane species, the altitudinal range of which more or less matches that of most forested areas in New Zealand, with a few species more widely distributed from the lowlands to the subalpine zone. A number of native taxa seem to have radiated extensively in high mountain or subalpine habitats (e.g., many Rhypodes (Lygaeidae), most Deraeocorinae, many Bipuncticoris species, and the genus Kiwimiris (Miridae)). The only endemic pentatomid, Hypsithocus hudsonae , is restricted to subalpine-alpine habitats. The evolution of these taxa may have followed that of the bulk of New Zealand shrubby and herbaceous plants; these have evolved in response to new environments of the Quaternary era (Wardle 1991). The majority of Targaremini species (Rhyparochromidae) occur from the lowland to the subalpine zones although most species are brachypterous, hence limited in their ability to disperse.
Some adventive species can be regarded as being synanthropic, i.e., living around human dwellings, e.g., Xylocoris galactinus , Lyctocoris campestris (Anthocoridae), Cimex lectularius (Cimicidae), Stenolemus fraterculus (Reduviidae), and, to some extent, Dieuches notatus (Rhyparochromidae).
Relatively little is known about the natural history of native Heteroptera. Host plants have been confirmed for less than 25% of species, mainly in the families Lygaeidae and Miridae. However, Appendix B lists over 350 plants recorded in association with New Zealand Heteroptera. Practically no life-cycle study has been published so far. The seasonality of species, especially the adult stage, is only becoming clearer in this catalogue with more data gathered from New Zealand collections. Adults are probably diurnal in most families, and although they may be active for most of the year, their peaks of activity are between November and March, that is, the end of spring (September-November), summer (December-February), and early autumn (March-May). The seasonality of immature stages as well as the breeding type of most species, i.e., the time of the year at which they reproduce, are mostly unknown. Population biology and locomotory activity remain virtually undocumented, although the present catalogue attempts to fill parts of this knowledge gap by providing observations on wing development which may be indicative of dispersal abilities. Current knowledge about feeding strategies is mostly extrapolated from what is known of family trends worldwide rather than based on direct observations of New Zealand species. The majority of Heteroptera found in New Zealand are phytophagous (plant-feeding) extracting sap directly from the plant vascular system (most families), feeding on seeds, developing fruits, or flowers (e.g., Lygaeidae, Pentatomidae, Rhyparochromidae), or sometimes pollen (e.g., some Miridae). The majority of species of the family Aradidae are thought to feed on the mycelia or fruiting body of various wood-rotting fungi. Almost all families of Heteroptera also include species that are predacious on insects and other arthropods (e.g., subfamily Deraeocorinae in the Miridae), and there are entire families that are predominantly predacious (e.g., Anthocoridae, Ceratocombidae, Nabidae, Enico-cephaloidea). Some predacious species may also at times have to feed on plant substances for moisture or to make up for lack of suitable prey (e.g., some Nabidae, Anthocoridae, Reduviidae). Only the introduced cimicid Cimex lectularius is haematophagous, feeding on the blood of vertebrates; there does not appear to be any evidence of disease transmission.
Little is known about the natural enemies of New Zealand Heteroptera. Hymenopteran egg-parasites, some birds (e.g., pipit, rook, starling), spiders, damsel bugs (Nabidae), ground-beetles, and mites have been observed as enemies of some Heteroptera in New Zealand, but published observations are few and far between. The authors' field experience suggests that spiders could be the most important predators, especially in open habitats such as tussock grasslands and alpine environments.
Economic importance.
Schuh & Slater (1995) and especially Schaefer & Panizzi (2000: Heteroptera of economic importance ) gave thorough up-to-date reviews on the economic importance of Heteroptera on a world basis.
Economic importance, as generally perceived in terms of direct damage to crops or disease transmission by a single species, is probably lower in Heteroptera than in other major insect orders.
In New Zealand, this is currently documented for a limited number of adventive species, e.g., Miridae- Engytatus nicotianae (vector of velvet tobacco virus), Closterotomus norwegicus (pest on various seed and vegetable crops), Sidnia kinbergi (pest on seed crops, strawberries, carrots); Pentatomidae - Cuspicona simplex (pest on solanaceous plants), Dictyotus caenosus (pest on boysenberries, lucerne), Nezara viridula (pest on a wide range of vegetable crops). In addition, species with pest status in other parts of the world, including neighbouring island countries and other parts of Australasia, represent potential biosecurity risks for countries like New Zealand that rely heavily on primary industry for their economy. For example, chinch bugs and other species of Lygaeidae have historically been among the most destructive plant-feeding pests in several countries of the world, hence the need to update the inventory of the New Zealand and neighbouring faunas continually through sustained fieldwork and taxonomic re-assessments.
Crop damage is also documented for some endemic species, e.g., Lygaeidae - Nysius huttoni (mostly crucifers and wheat); Miridae - Diomocoris maoricus (peach), Lincolnia lucernina (lucerne).
As a group, Heteroptera can serve humans and the environment in positive ways, especially predacious species which can be useful biological control agents. The importance of zoophagous Heteroptera for integrated pest management programmes has been reviewed by Alomar & Wiedemann (1996) and Schaefer & Panizzi (2000). In general, this issue has received more attention in overseas countries with larger faunas than in New Zealand. For example, Anthocoridae have been identified as important predators of thrips, mites, and Lepidoptera eggs. Predatory Miridae have been successfully used to control leafhoppers. Predatory Pentatomidae of the subfamily Pentatominae have acted as biocontrol agents against lepidopterous caterpillars. Some species of Microvelia (Veliidae) have been used for mosquito or rice planthopper control.
The subject of beneficial Heteroptera has received limited attention in New Zealand, e.g., Orius vicinus (adventive Anthocoridae, in orchards), Cermatulus nasalis and Oechalia schellenbergii (native Asopinae, in a range of situations). In general, most native predacious and zoophytophagous species have not been investigated for use as biocontrol agents.
Finally, other seemingly economically unimportant groups of Heteroptera may also be important to humans or to nature conservation. Notonectidae and Corixidae, for example, may have positive importance as foodstuffs for fish, as good indicators of water quality, or as biological control agents against the larvae of disease vector mosquitoes.
Conservation status.
The Department of Conservation has responsibility for protecting and conserving New Zealand's native plants and animals. The Department's Species Priority Ranking System established by Molloy et al. (1994) provides criteria for scoring species according to various levels of threat, so that management and/or recovery plans can be subsequently established. A list of priority invertebrate species for conservation was established in this way by Molloy et al. (1994). McGuinness (2001) developed species profiles for species on the list, providing additional descriptive information to initiate or support key conservation actions. In addition, McGuinness (2001) added a number of invertebrates of potential conservation interest to the original list.
The Department of Conservation's Species Ranking System is summarised in Table 5. Criteria in bold are thought to be more readily applicable to Heteroptera given current levels of taxonomic and biological knowledge. Four species of Heteroptera were profiled by McGuinness (2001): Rhopalimorpha alpina (Acanthosomatidae, conservation category X), Hypsithocus hudsonae (Pentatomidae, conservation category I), Empicoris aculeatus , and E. seorsus (Reduviidae, conservation category I).
The conservation status of these species is reviewed here. The current status of Hypsithocus hudsonae seems appropriate. Rhopalimorpha alpina could be more appropriately regarded as a category I species. As far as the authors know, it has never been 'presumed extinct'. Although this species has not been sighted for a number of years, this is probably due to a lack of active surveying, a low knowledge of its biological requirements, or to a localised or disjunct geographic distribution.
The authors also think that the Empicoris species should both be removed from the list of threatened species. Information on this genus in New Zealand is simply too scanty for any serious evaluation. The situation of Empicoris species could apply to several other Heteroptera genera not well revised taxonomically, little known biologically, or not yet targeted by specialised field surveys.
When the above criteria are applied, new knowledge brought forward in the present catalogue suggests that over sixty-five (65) endemic Heteroptera may, however, be of potential conservation concern. These species are listed in Appendix I (names preceded by an asterisk).