British Insects: the Families of Hemiptera

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L. Watson and M. J. Dallwitz

Introduction

This data set is generated from a DELTA database (Dallwitz 1980; Dallwitz, Paine, and Zurcher 1993). The original intention of the ‘British Insects’ suite of packages, of which it forms part, was primarily to present scans of the fine hand-coloured engravings of insects in John Curtis’s British Entomology: illustrations and descriptions of the genera of insects found in Great Britain and Ireland (1824–1840). The first 12 volumes of the first edition (up to 1835) were directly available to us, and pages issued from 1836-1840 have been accessed from other sources (see Notes on John Curtis’s British Entomology).

In addition to presenting Curtis’s and other early illustrations, however, all the ‘British Entomology’ subsets incorporate descriptive data organized under the DELTA system, and purport to offer at least partial identification and information retrieval facilities via the interactive program Intkey. The extent to which they succeed at this early stage of development has yet to be determined, but in any case the DELTA data (from which updates of the interactive packages are easily generated) are readily accessible for improving, correcting and extending.

With more work, this package would permit reliable identification of all the families of British Hemiptera, via standard morphological and ecological characters. At this stage, it carries preliminary but hopefully workable descriptions of all the families currently recognised as ‘British’, except that the Aphidoidea and Coccidoidea are temporarily represented by outdated, sensu lato versions of the Aphididae and Coccididae. The families are extensively illustrated, Curtis’s plates being supplemented by scans from Saunders (1892, Heteroptera), Edwards (1896, Homoptera) and Southwood and Leston (1959, Heteroptera). Family descriptions were compiled, in the first instance, from the detailed taxonomic descriptions and keys provided by Woodward et al. (in Britton et al. 1970) and Imms (1957); then checked and extended with reference to Unwin’s excellent AIDGAP key (2001), and further improved via Dolling’s (1991) account. The latter presents detailed information on nymphs, which needs to be incorporated; and a continuing operation involves gathering descriptive data from the classic Southwood and Leston treatment of British land and water bugs, which has never been updated or superseded and is sadly out of print.

The nomenclature was initially aligned with the original checklist of Kloet and Hincks (1945), after which the rather numerous names not listed by them were nearly all tracked down with resort to the Second Edition of that work (Southwood et al. 1964). Continued recognition of the traditional taxa Homoptera and Heteroptera, sunk by modern cladisticians in a hopelessly heterogeneous and uninformative version of the Hemiptera, is supported by a recent DNA study (see Nan Song et al., 2012: A Molecular Phylogeny of Hemiptera Inferred from Mitochondrial Genome Sequences. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0048778).

Curtis’s plates are cited in the Intkey displays of taxon images, where they are accompanied by scans of his text. As well as legends for the illustrations and formal taxonomic descriptions, the latter offer numerous examples of his entertaining, informative and elegantly expressed notes on sources of specimens, morphological interpretations, classificatory methodology, general biology, etc. We recommend (for example) the erudite exposition on the ‘affinities’ of Gampsocoris (Berytidae), invoking comparative morphology and ecology; and the delicious description of the Bed-bug, with alarming advice on how to control it.

Family assignments of all the insects illustrated have been checked at family level, in effect with reference to the family descriptions in the cited works, by ‘identifying’ the illustrations using the Intkey package. While it has thus been ascertained that the illustrations conform reasonably well with the family assignments, checking on the generic and specific identities of the insects depicted has so far been fairly superficial. Persons wishing to use the pictures for their own, critical purposes should take the necessary precautions for themselves.

All the compilations in our ‘British Insects’ series, including this one, are readily accessible for extending, improving and making corrections. Organization under the Delta system ensures ready access for corrections and improvements. Informed criticism and constructive input are of course welcome, and will be appropriately acknowledged. Alternatively, complete Delta data sets can be donated if required for teaching purposes, or to any professional or amateur entomologist or organization interested in developing them further.

Edited 16 December 2011


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