Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

FNZ 59 - Erotylinae (Insecta: Coleoptera: Cucujoidea: Erotylidae) - Introduction

Skelley, PE; Leschen, RAB 2007. Erotylinae (Insecta: Coleoptera: Cucujoidea: Erotylidae): taxonomy and biogeography. Fauna of New Zealand 59, 59 pages.
( ISSN 0111-5383 (print), ; no. 59. ISBN 978-0-478-09391-9 (print), ). Published 07 Sep 2007
ZooBank: http://zoobank.org/References/351ADE1F-65D8-44E1-9F57-C94CACEA93DF

Introduction

In Fauna of New Zealand 47, Leschen (2003) restructured the family Erotylidae to include the family Languriidae (see also Wegryznowicz 2002) and examined the status of the higher taxa based on a cladistic analysis of adult characters. He also reviewed the New Zealand species that would have been included in the former family Languriidae. The purpose of this paper is to complement Leschen’s (2003) review of New Zealand’s Erotylidae by covering the species of subfamily Erotylinae. The Erotylinae, also known commonly as the “pleasing fungus beetles” for their often striking colours (which do not occur in New Zealand species), are represented in New Zealand by two genera, one of which is endemic with several species. Various authors have described erotyline species, or created lists for them, but none has attempted to evaluate these taxa and update their taxonomy.

Early collections of the erotyline fauna followed the standard tradition for the British Empire whereby expeditions or colonists provided specimens for enthusiastic European workers. Among these were two New Zealand entomologists, Thomas Broun and Richard Helms, who provided or described much of the Erotylinae material used to define the fauna. Thomas Broun not only described thousands of beetle species, but in a long series of works, also attempted to list the beetle fauna of New Zealand.

The first New Zealand erotylid species described was Engis politus White, 1846, later transferred by Crotch (1876) to the genus Thallis Erichson. White’s description is very short, lacking data such as length, but a type exists and was available for this study. Next came the descriptions of species in Cryptodacne Sharp, 1878: Triplax brounii Pascoe, 1876, Cryptodacne synthetica Sharp, 1878, and Cryptodacne ferrugata Reitter, 1879. Following these species, came Broun’s works describing Cryptodacne lenis Broun, 1880, Cryptodacne vagepunctata Broun, 1882, Cryptodacne vittata Broun, 1886, Cryptodacne pubescens Broun, 1893, and Cryptodacne ocularia Broun, 1913. Broun also covered species of earlier workers by reprinting, or translating, the original work. One species listed by Reitter (1879: 183) and Broun (1910: 78) as an erotylid is Tritomidea rubripes Reitter, 1879, which was transferred to the family Cerylonidae by Ślipiński (1990: 70) under the genus Hypodacnella Ślipiński.

The only larval work has been the description of Cryptodacne synthetica by Sen Gupta (1969) where also the tribe Cryptodacnini is defined, presumably only for Cryptodacne, in his classification for the family. Lawrence (1988) also commented on the larval characters of Cryptodacne compared with Australian Cnecosa Pascoe and other Dacnini.

Based on adult characters, all members of the Erotylinae in New Zealand belong in the tribe Dacnini, a placement that is firmly established (Wegrzynowicz 2002, Leschen 2003). Continued retention of a single genus tribe based on a few larval characters is not advised. Thus, the Cryptodacnini are here considered synonymous with the Dacnini. However, the relationships of dacnine genera to one another around the world are not well understood. A more thorough cladistic analysis of the Dacnini is needed to gain a better understanding of this mainly Gondwanan tribe.

Most New Zealand species of erotylines are fairly widespread, and all, apart from two species, are found in both islands. We describe a new species, C. rangiauria, which is restricted in distribution to the Chatham Islands, located some 800 km east from the coast of the South Island. There is some controversy about the origin of the Chatham Islands fauna, mainly relating to whether the taxa arrived there by dispersal, or whether the fauna was isolated through vicariance (Trewick 2000). One test of the dispersal theory is to determine the phylogenetic relationships of Cryptodacne and the relationship of C. rangiauria to other members of the genus. A basal position in the tree, as sister taxon to the remaining members of the genus, could indicate a vicariant event that separated C. rangiauria from the rest of New Zealand taxa, whereas a more derived position could represent a dispersal event. Source areas of the Chatham Islands have not been adequately identified and we attempt to determine whether these are in the South Island, North Island, or both (Craw 1988, 1989; Emberson 1995, 1998) by examining all the available phylogenetic information for plants and animals.

The phylogeny of Cryptodacne may also help determine the taxonomic status of the species C. brounii, which is very similar to the species C. lenis. Cryptodacne brounii is known from two specimens described by Pascoe (1876) from ‘Auckland,’ and placing this species in the phylogeny of the genus may provide clues to its validity as a species.

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