FNZ 45 - Nemonychidae, Belidae, Brentidae (Insecta: Coleoptera: Curculionoidea) - Introduction
Kuschel, G 2003. Nemonychidae, Belidae, Brentidae (Insecta: Coleoptera: Curculionoidea). Fauna of New Zealand 45, 100 pages.
(
ISSN 0111-5383 (print),
;
no.
45.
ISBN 0-478-09348-9 (print),
).
Published 28 Apr 2003
ZooBank: http://zoobank.org/References/9143DAB5-942F-4E3B-8E68-D47BB28498D5
Introduction
This contribution to the Fauna of New Zealand series is the fourth on weevils. Weevil, a word of Germanic origin, was used indiscriminately for any coleopteron in the 9th to 15th century (Klausnitzer 1983), but became gradually displaced by beetle, Kāfer, chafer, biller, and others in Germanic languages. It is now almost exclusively reserved for beetles of the superfamily Curculionoidea. Derived from a number of spelling forms, such as webila, uubil, wibil, wibel, and wiebel, it ended up as weevil in modern English. The group of beetles it now represents stands out amongst all others by having the head extended forward to a kind of snout or proboscis called a rostrum. Because the group is well represented in Europe in forests, orchards, fields, and barns, it was given vernacular names in most countries. Apart from weevil in English, these beetles are known as Rūsselkāfer (snout-beetle) in German, snudebiller in Danish, charançon in French, gorgojo in Spanish, and gorgulho in Portuguese. The last two names were derived from the Latin word "curculio", which Linnaeus (1758) adopted as a genus to embrace nearly all Curculionoidea described by him, and Latreille (1802) then selected this name as the basis for his family Curculionites.
Schoenherr (1826), who pioneered the study of weevils, distinguished in his 'tabula synoptica familiae curculionidum' two groups - ordo Orthoceri and ordo Gonatoceri - basing the division on an obvious feature of their antennae: those with straight antennae he called Orthoceri, and those with geniculate antennae he named Gonatoceri. This division is not strictly phylogenetic, but has been, and still is, popular and practical to the current day.
Under the name of Orthoceri are grouped five (Kuschel 1995) or six families (Oberprieler 2000), and four of these are represented in New Zealand: Nemonychidae, Anthribidae, Belidae, and Brentidae. Absent are Attelabidae and Caridae, the latter having just a few relict forms in Australia and in the Andes of Chile and Argentina. Orthocerous weevils are perceived as primitive because of the plesiomorphic state of their antennae and other external and internal morphological structures. They are consequently regarded as ancestral and are expected to appear early in the fossil record. A section is devoted to the paleontological evidence of the earliest, mainly Mesozoic, Orthoceri known with some comments on the reliability of their systematic placement.
Orthoceri constitute a small minority of the New Zealand weevil fauna, amounting to only 74 endemic species at present, out of some 1100 species estimated as valid amongst 1500+ names already proposed, or only 6.7% of the total known fauna. This percentage will probably be lowered to about 4% once hundreds of Gonatoceri weevils awaiting description are dealt with. The largest of the orthocerous weevil families is Anthribidae, with 60 species, all but two endemic (Holloway 1982). The other three families have 17 species, 16 of them endemic, and one introduced for partial biological control of gorse (Ulex europaeus).
If Orthoceri appeared earlier in geological times, the question arises whether the plants they were associated with were of the early type as well. Host associations can, of course, only be surmised when dealing with fossils, but it can be done with some confidence if the contemporary fossil flora is also known and the host plant associations of the extant weevil fauna shows a disproportionately high incidence of species confined to ancestral groups of plants. Considering only phanerogamic hosts, 12 orthocerous species are host-specifically linked with gymnosperms in New Zealand (if two anthribid species of the genus Cacephatus are included) and 62 with angiosperms and/or their fungi, or 16% versus 84% respectively. On the other hand, of all of the weevils known or presumed to occur exclusively on conifers, the ratio is 12 Orthoceri to 7 Gonatoceri (63% versus 37%) in New Zealand. By comparison, Australia has 34 Orthoceri and 22 Gonatoceri (61% versus 39%), and Chile 16 Orthoceri and 15 Gonatoceri (52% versus 48%) described weevil species on conifers. These three southern hemisphere countries show patterns in sharp contrast with those of the northern hemisphere where Gonatoceri species on conifers prevail by far over Orthoceri ones. The Orthoceri/Gonatoceri ratio in Europe on conifers is of the order of 2.5% to 97.5%. I am not aware that other workers have considered ratios of their groups for the two hemispheres,or have possibly found similar differences, and, if so, how the phenomenon was explained. I should think that the less severe climate changes of the southern hemisphere and the loss of Araucariaceae and Podocarpaceae in the temperate northern hemisphere has had a good deal to do with it, as well as a most successful proliferation in the northern latitudes of Scolytinae. Table 1 lists the hosts plants for the 17 species of the families revised in this contribution.
Richness of the New Zealand weevil fauna
The marked prevalence of weevils over any other comparable group of beetles in the composition of local faunas is confirmed for New Zealand. Thomas Broun in the years 1880-1923 recorded 4323 beetle species, and Watt (1977) worked out that 1198 of them (27.7%) were weevils. In a survey of a few hectares of a coastal strip of an Auckland city suburb by Kuschel (1990), which included also a rich adventive element, better adapted to rural and urban conditions than the autochthonous component, 198 out of 982, or one fifth (20%) of the total beetle fauna were weevils. Since Fabricius described the first species collected by Captain Cook's Endeavour, 1501 names have become available for native weevil species. It is estimated that a good many of these names, at least one quarter (25%), will succumb to synonymy and bring down the number of species to about 1100.
Table 1. Host plants of New Zealand Nemonychidae, Belidae, and Brentidae species.
Excepting Lasiorhynchus barbicornis, adults of all other weevil species dealt with in this revision are to a greater or lesser extent host-specific, but larvae may on occasion also develop on plants other than the adult host. If this is the case, the species is marked with an asterisk (*).
Gymnospermae
Araucariaceae
Agathis australis: Lasiorhynchus barbicornis
Cupressaceae
Libocedrus bidwillii: Strobilobius libocedri
Phyllocladaceae
Phylloladus alpinus: Rhicnobelus aenescens
Rhicnobelus metallicus
Rhinorhynchus halli
Rhinorhynchus halocarpi
Rhinorhynchus phyllocladi
Rhinorhynchus rufulus
Phyllocladus toatoa: Rhicnobelus metallicus
Phyllocladus trichomanoides: Rhicnobelus metallicus
Rhinorhynchus phyllocladi Rhinorhynchus rufulus
Podocarpaceae
Dacrycarpus dacrydioides: Rhinorhynchus rufulus
Dacrydium cupressinum: Agathinus tridens
Lasiorhynchus barbicornis Rhicnobelus metallicus Rhinorhynchus rufulus
Halocarpus bidwillii: Agathinus tridens Rhinorhynchus halocarpi Rhinorhynchus phyllocladi Rhinorhynchus rufulus
Lepidothamnus laxifolius: Rhinorhynchus rufulus
Manoao colensoi: Rhinorhynchus phyllocladi Rhinorhynchus rufulus
Podocarpus hallii: Agathinus tridens Rhinorhynchus rufulus
Podocarpus nivalis: Rhinorhynchus rufulus
Podocarpus totara: Agathinus tridens Rhicnobelus metallicus Rhicnobelus rubicundus Rhinorhynchus phyllocladi
Rhinorhynchus rufulus
Prumnopitys ferruginea: Agathinus tridens
Rhinorhynchus rufulus
Angiospermae
Araliaceae
Pseudopanax arboreus: Aralius wollastoni
Pseudopanax crassifolius: Aralius wollastoni
Pseudopanax lessonii: Aralius wollastoni
Asteraceae
Brachyglottis repanda: Lasiorhynchus barbicornis
Olearia nummulariifolia: Agathinus tridens*
Cornaceae
Corokia buddleioides: Agathinus tridens*
Corynocarpaceae
Corynocarpus laevigatus: Lasiorhynchus barbicornis
Eleocarpaceae
Aristotelia serrata: Pachyurinus sticticus*
Epacridaceae
Cyathodes sp.: Agathinus tridens*
Ericaceae
Gaultheria sp.: Agathinus tridens*
Fabaceae
Ulex europaeus: Exapion ulicis
Fagaceae
Nothofagus cliffortioides: Pachyurinus sticticus*
Nothofagus menziesii: Cecidophyus nothofagi
Nothofagus solandri: Pachyurinus sticticus*
Malvaceae
Hoheria sp.: Lasiorhynchus barbicornis
Meliaceae
Dysoxylum spectabile: Lasiorhynchus barbicornis
Monimiaceae
Hedycarya arborea: Lasiorhynchus barbicornis
Laurelia novae-zelandiae: Lasiorhynchus barbicornis
Myrtaceae
Metrosideros albiflorus: Neocyba metrosideros
Metrosideros excelsus: Neocyba metrosideros
Neocyba regalis
Metrosideros robustus: Neocyba metrosideros
Proteaceae
Knightia excelsa: Lasiorhynchus barbicornis
Toronia toru: Rhicnobelus rubicundus*
Rubiaceae
Coprosma sp.: Agathinus tridens*
Past methods of collecting were largely confined to sweeping or beating vegetation, or turning over rocks, logs, and other objects on the ground. Because of Broun's deep involvement with the study of the New Zealand beetles, the more easily accessible fauna of lowlands was reasonably well covered. The smaller, cryptic beetles of forest litter, even that of the lowlands, together with moss mats and the hardly explored montane environment, remained to a large extent undescribed. Judging by the richness and variety of insects collected since by research centres and museums, the number of native weevils in this country should easily reach 1800 species. Including the adventive species, the ultimate number should come to around 2000.
Composition of the New Zealand weevil fauna
Before dealing with the subject matter of this section, it is necessary to state which classificatory system is being followed, because there is little agreement at present on the number of families of the weevils. If the old tradition of emphasising morphological distinctiveness, including the presence of ancestral features (plesiomorphies) is followed, a proliferation of families is a natural consequence. One hundred years ago six families were recognised: Anthribidae, Aglycyderidae, Proterhinidae, Brentidae, Curculionidae, and Scolytidae. The ambit of these families did not change to any major degree until Crowson (1955) introduced innovations of phylogenetic significance. The result was that Proterhinidae and Scolytidae were demoted, and Nemonychidae, Belidae, Oxycorynidae, and Apionidae were proposed as new, to which the family Allocorynidae was subsequently added (Crowson 1981). Kuschel (1995), by dissecting a large assortment of species of all major weevil groups, produced a matrix of 141 characters, which was processed through PAUP. Six family clades were obtained whereby Oxycorynidae, Allocorynidae, and Aglycyderidae of Crowson were included in Belidae, and Apionidae in Brentidae. Oberprieler (2000), in examining a few controversial taxa in and around Brentidae, removed Carinae from this family to raise it to family status. Kuschel's system, with inclusion of the alteration introduced by Oberprieler, is adopted in the present paper. Thompson (1992), Zimmerman (1994), Zherikhin & Gratshev (1995), and Alonso-Zarazaga & Lyal (1999) proposed or followed other classifications accepting anything from 11 to 18 families. Because these do not provide characters for a phylogenetic analysis and proper systematic assessment, they are not considered here.
Of the seven accepted weevil families, five occur in New Zealand: Nemonychidae with four native species, Anthribidae with 58, Belidae with seven, Brentidae with six native and one introduced species, and Curculionidae with approximately 1100 valid species. The family Attelabidae is not present in New Zealand, and is present with only one rhynchitine species in New Caledonia and four rhynchitines in Chile. The family Caridae has six extant species - four in Australia and two in Chile - but fossils are known from the Baltic amber (Voss 1953, Kuschel 1992) and others from the Lower Cretaceous are considered probable members of the family (Kuschel 1983).
The present paper revises the families Nemonychidae, Belidae, and Brentidae. The fourth family, Anthribidae, the largest of the four orthocerous families in New Zealand, was revised by Holloway (1982) in great detail and with a profusion of illustrations. The three orthocerous families treated here are poorly represented, but being of basic ancestral groups, are of special biogeographic interest. Nemonychidae, with only 70 known species world-wide, is represented by four species in New Zealand, making up 5.7% of the world fauna. By comparison, the ratio is 1.87% for the world fauna of Anthribidae, 2.0% for Belidae, 0.16% for Brentidae, and 2.29% for Curculionidae. Large groups elsewhere, for instance Dryophthorinae, Baridini, Lixini, Anthonomini, Ceutorhynchini, Zygopini, and Mesoptiliini (Magdalidini), to cite just a few weevil groups, have no native species in New Zealand. On the other hand, groups rather poorly represented elsewhere, in areas of a similar climate, for instance Eugnomini, Molytini, Erirhinini, and Cryptorhynchini, as well as Cossoninae, are very richly represented in this country.