Heliothine Moths Of Australia: A Reference Guide To Pest Bollworms And Related Noctuid Groups.

Field: Agricultural and Biological Sciences (Life Sciences)

By M. Matthews. CSIRO Publishing, Collingwood, Victoria, Australia. 1999. Pp. 332, colour illustrations. Book (hardcover) and CD-ROM. $US90.00. ISBN 0643 06035 6. On a global scale, noctuid moths of subfamily Heliothinae are perhaps the most serious of all pest Lepidoptera. By consuming the flowers and fruits of their larval host plants, not only do heliothines cause proportionately greater losses in agricultural production than species that attack only the leaves, but they also come into direct competition with humans. Consequently, there is massive expenditure in chemical control measures, which are generally only partially successful. The direct cost of applying these chemicals is further exacerbated by the indirect cost to the environment of prolonged and repeated pesticide applications, which remains unquantified but is probably even greater. Growing concern for both the cost and environmental impact of pesticides is driving the search for new control strategies, and central to this new approach is a critical insight into the systematics of the pest group. Improved understanding of the relationships among heliothine genera and species will permit more specific targeting of biological control agents. In Australia, this work is centred on the development of genetically modified strains of nuclear polyhedrosis viruses (NPVs) for Helicoverpa control. Thus, the Cooperative Research Centre for Sustainable Cotton Production, Cotton Research and Development Corporation, Grains Research and Development Corporation, and CSIRO collaborated to fund a review and revision of Australian Heliothinae. The author chose to write this book for a target audience comprising ‘practical entomologists’, such as agriculturalists, biocontrol engineers, ecologists and molecular biologists. Thus, although it remains fundamentally a taxonomic treatise, the traditional layout of a monographic work has been modified. Purely taxonomic information, such as species synonymies and type data, which is not of prime importance to the target audience, is excluded from the main text. Instead, such information is placed either into appendixes or onto the accompanying CD-ROM. Specimen information is usually presented in taxonomic works as a long list of material examined in the text. Here, it is provided in both word processor and (Australian specimens only) spreadsheet formats on the CD-ROM, and is thus a much more flexible and useful research tool. The overall result is a taxonomic product in which the information required by the target audience is presented in a streamlined and accessible form (mostly, see below), but neither are the needs of the systematic community ignored. Following an introductory section, in which the objectives and layout of the book are explained, there are five general review sections. In keeping with its stated objectives, the first of these is a summary of the ‘Agricultural importance and control of Heliothinae in Australia’. However, as Helicoverpa armigera and Helicoverpa punctigera are currently the only major heliothine agricultural pests on the continent, discussion is restricted to these two species. In the next section, observations of life history strategies, behaviour and other biological traits of Australian Heliothinae are discussed and set into the global context of heliothine biology. This is followed by a review of heliothine systematics, both in general and with particular reference the Australian taxa. The fourth section describes heliothine morphology, both of adults and immature stages, whereas the last reviews heliothine phylogeny. In this section, Matthews builds upon his earlier morphological work by incorporating evidence from more recent analyses based upon molecular sequence data to produce an improved estimate of phylogenetic relationships among the genera. Matthews also presents a brief analysis of the phylogenetic relationships among the Australian Helicoverpa species. The main part of the book is occupied by the genus and species accounts, of which the latter are arranged alphabetically for ease of use. For each of the five genera, there is a diagnosis, followed by succinct sections on monophyly (only Heliothis is not monophyletic), global distribution, general biology and pest status. Each of the thirty-eight species accounts begins with a description of one or two sentences, which gives a general impression of the moth, followed by a detailed diagnostic section in which the features that distinguish a species from similar species are made plain. This is the most important written section for those who need to identify heliothine moths. The remainder of the species account is collated under the general heading ‘Description’ and it is here that the presentational consistency breaks down somewhat. Matthews clearly intended to streamline these species accounts so that they included only the information of relevance to his target audience of ‘practical entomologists’, but was constrained by the standard format of this monographic series. Each species account includes a lengthy description of the adult moth. I do not understand the purpose of this, as the important written information for identification is already provided in the differential diagnoses and readers will, in any case, refer to the colour plates. These descriptions have also led to redundancy and unnecessary repetition. For example, in the introductory overview of heliothine morphology (page 15), we are told that ‘the compound eye is smooth and unlashed, varying in size and shape from full and globular to very small and eliptoid [sic]’. However, no Australian heliothine shows any condition other than the former and thus the sentence ‘Compound eye fully developed, globular’ is needlessly included and repeated thirty-eight times, once in each species account. Likewise, the excellent keys to species based on male and female genitalia mean that formal descriptions of these organs are supererogatory. This descriptive material should have been removed to an appendix, as were the nomenclatural discussions, or even consigned to the CD-ROM. By contrast, while there are no keys to larvae or pupae, neither are there lengthy descriptions of larval or pupal morphology. Instead, in a subsection entitled ‘Biology and immature stages’, concise descriptions of late (usually final) instar larval colour pattern and skin spinulation, and pupal structure are given; otherwise the reader is referred to the excellent colour plates. The only exceptions are the serious pest species, Helicoverpa armigera and H. punctigera, for which detailed differential diagnoses of both late instar larvae and pupae are provided. This subsection also includes larval host plant records, tabulated where appropriate. A distribution map of Australian records is provided for each species, together with flight period information, which is presented as a histogram of monthly records when warranted by the data density. A miscellaneous ‘Remarks’ subsection concludes each species account. Next comes the Nomenclatural Appendix, comprising a checklist of Australian Heliothinae, full species synonymies (including full details of type series and lectotype designations), and details of the slide-mounted material examined. I can understand Matthews' concern that his audience of ‘practical entomologists’ could be unresponsive to such taxonomic minutiae, but I, for one, am pleased that this section was included in the printed text. I found the attention to detail compelling. But then I freely admit I enjoy solving the taxonomic, bibliographic and nomenclatural riddles that have been bequeathed to us by our predecessors. The insight they provide into human nature and historical contingencies can be quite fascinating. This book is lavishly illustrated and the figures and plates are of the highest quality. All male and female genitalia (where available) are figured as monochrome photographs. Vesicas were everted using the ‘phalloblaster’ and mounted such that their three-dimensional coiled structure is spectacularly clear. The exceptional coiling and spination of the vesicas of Helicoverpa species makes eversion particularly difficult, so to facilitate species identification in this important pest genus, photographs of uneverted vesicas are also given. Forewings, legs and male terminal abdominal segments, where relevant to the text, are also illustrated as monochrome photographs. Electron micrographs of larval skin spinulation and pupal cremasters complete the monochrome plates. The colour plates are equally impressive. There are eight plates of conventionally prepared dead adult moths, which together with the differential diagnoses, can be used to identify most species (with the exception of some very difficult Heliocheilus). Additional colour plates illustrate living moths, mostly resting on various grass stems, and living larvae, mostly posing on apparently the same grass stems. Separate plates illustrate the diagnostic features of Helicoverpa armigera and H. punctigera adults and larvae. There are also colour photographs of living pupae and sixteen habitat shots of heliothine field survey collecting localities. Finally, one monochrome and two colour plates provide highlighted illustrations of technical terms associated with wing pattern, venation and genital structure. There are very few errors in the printed text and the author pointed out most to me. The majority of these are quite trivial, concerning such matters as missing running heads to some of the colour plates, occasional (but obvious) misspellings and lack of emboldening of Australothis in Figs 1 and 2 (giving the false impression that this genus does not occur in Australia). Only four mistakes are potentially misleading. First, on page 17, setae L1 and L2 in final instar Heliothis phloxiphaga come to lie in a horizontal plane, not vertical as printed. Second, on colour plate 3.1, the claviform stigma is incorrectly labelled as ‘reniform stigma’; the real reniform stigma is the larger and more distal of the two labelled as such. Third, on plate 24.5, a small red open circle highlighting the ampulla has not been printed, making it difficult to identify this minute lobe on the dorsal edge of the sacculus. Finally, in the details of plate 7 (p. 298), the name ‘Heliocheilus cladotus’ has been omitted before the data for Fig. 25, although the information in the corresponding figure legend is correct. The accompanying CD-ROM contains four folders. ‘Material examined’ is a full list, in Microsoft Word 97 and rich text file formats, of specimens examined and includes standard taxonomic data on number, sex, locality, date of collection, collector and depository. ‘Nomenclatural database’ includes a zoological catalogue written using the taxonomic package, platypus. Unfortunately, this program does not yet seem to be widely employed outside Australia, thus severely restricting the current utility of the catalogue to external users. The database can be opened using Microsoft Access, once it has been copied to a writeable disc and the read-only attribute turned off. However, I found the resulting thirty-one tables totally unintelligible and there was also the ominous warning that any changes made using Access ‘may have unpredictable results if the file is subsequently opened with platypus’. My cynical side cannot help but see a subtle sales pitch here. ‘Specimen list’ contains Australian specimen data as a Microsoft Excel 97 spreadsheet, a delimited text file and formats suitable for viewing using GIS packages such as MapInfo and ArcView. Finally, ‘Type specimen images’ contains images (TIF format) of eighty-one primary types of Australian heliothine species (including synonyms, but excluding infrasubspecific taxa and homonyms). Missing are those of Helicoverpa armigera (Hübner) and three of its synonyms, which Matthews either did not examine or could not locate. There can be no doubt that monographs and taxonomic revisions form the bedrock of biological science. They collate and interpret fundamental data derived from individual specimens, and provide critical appraisal of species limits, relationships and distributions. Unfortunately, however, monographs and revisions are presented all too often in a very formal and, frankly, boring format, in which the important data they contain are not apparent. Consequently, these basic information sources often go unappreciated by those for whom the information could be of the greatest use. The present work is an excellent example of why this need not be so. By carefully considering his target audience, Matthews has ensured that they can find the information they want, in a form that is useful to them, while at the same time ensuring that the basic body of systematic data is also recorded in a flexible and useful format. I would recommend this book to virtually everyone with an interest in biology: to systematists, as an example of how to ensure taxonomy and revisionary monographic studies remain relevant in the 21st century; to ‘practical biologists’, as an example of the sort of thing they could have had, if they had known it could be provided; and to publishers, as an example of how extremely saleable taxonomic products of very high quality can be made widely available at relatively low cost.