Insects of Britain and Ireland: butterflies (Lepidoptera-Papilionoidae)

DELTA home

L. Watson and M. J. Dallwitz


This data set is generated from a DELTA database (Dallwitz 1980; Dallwitz, Paine, and Zurcher 1993). It currently permits interactive identification and automated retrieval of descriptive information to the levels of family and genus, but species should be readily identifiable with reference to the comprehensive illustrations accompanying the generic descriptions. In this connection, we are unable to resist drawing attention to the inadequacy of nearly all the readily available books and Internet sites purporting to enable people to identify organisms; viz., the absence of keys. This failing is the more remarkable in the present case, given that the rather obvious advantages of keys were explained and exemplified with reference to British butterflies by Stainton in 1857 (pp. 4–9)! He simultaneously demonstrated the (again, rather obvious) identificatory value of differences in size, which are extensively de-emphasized by professional taxonomists when constructing keys. Our package incorporates comparative data on all the characters traditionally used to describe butterflies, and users will see that the Intkey display of ‘best’ characters for identification (calculated to express identificatory efficiency, including ease of access) presents ‘wingspan’ at the top of the list.

The original intention of the ‘Insects of Britain and Ireland’ suite of packages, of which this 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 the pages issued from 1836 on have been accessed from other sources (see Notes on John Curtis’s British Entomology). In addition to illustrations from Curtis and other classic works (Newman, 1869 and 1871; Nodder and Shaw, 1789 et seq.; Hubner, 1795; Stephens, 1828–1846; Morris, 1843; Coleman (1860); Kirby, 1907; see References), the present package offers original photographs portraying nearly all the species. The latter mainly depict specimens from a collection made by L. Watson between 1948 and 1960, supplemented by recent photographs of living butterflies by Giles Watson. Details of dates and localities of specimens depicted can be accessed via the Intkey displays of the images.

The generic descriptions were first compiled from works listed in the References, in particular from Meyrick and South, and then rather extensively checked against specimens in Watson’s small collection. In effect they represent a first draft, and being in DELTA format, they are easily accessible for correcting and improving. They could also readily be extended to species level, or the present character list could be augmented and adapted for application to other geographical regions.

The nomenclature and classification have been aligned with Bradley’s (2000) checklist, to the extent of including rather numerous species the ‘British’ status of which is tenuous to say the least. Some of these presumably represent genuine, wind-assisted migratory penetrations beyond the normal ranges of species, or accidental transport by human agencies (ships, aircraft), and a few undoubtedly attest to sad, fairly recent extinctions. Others probably reflect honest mistakes of one sort or another, but one or two of the inclusions represent early records that were probably fraudulent.

Edited 16 May 2016