Forest Insects a Guide to Insects Feeding on Trees in Britain
Total Page：16
File Type：pdf, Size：1020Kb
Forestry Commission D BEVAN ARCHIVE A guide to insects feeding on trees in Britain r Forestry Commission Handbook 1 Forest Insects A guide to insects feeding on trees in Britain By D. Bevan Formerly Principal Entomologist, Forestry Commission The author was greatly helped during the compilation of this handbook by T G Winter, J T Stoakley, M R Jukes and C 1 Carter LONDON: HER MAJESTY’S STATIONERY OFFICE © Crown copyright 1987 First published 1987 HMSO ISBN 0 11 710200 8 BOOKS ODC 453 : 145-7 : (410) HMSO publications are available from: K eyw ords: HMSO Publications Centre Insects. Entomology. Forestry (Mail and telephone orders only) PO Box 276, London. SW8 5DT Telephone orders 01-622 3316 General enquiries 01-211 5656 Acknowledgements (queuing system in operation for both numbers) Line drawings by N J Fielding HMSO Bookshops 49 High Holborn, London, WC1V 6HB 01-211 5656 (Counter service only) Stereoscan photographs by M R Jukes 258 Broad Street, Birmingham, B1 2HE 021-643 3740 Colour photographs from the Forestry Commission collection Southey House, 33 Wine Street, Bristol. BS1 2BQ (0272) 24306/24307 The photograph of Tetropium gabrieli is by Dr M Speight 9-21 Princess Street, Manchester, M60 8AS 061-834 7201 80 Chichester Street, Belfast, BT1 4JY (0232) 238451 Enquiries relating to this publication should be addressed 13a Castle Street, Edinburgh, EH2 3AR 031-225 6333 to the Technical Publications Officer, Forestry Commission Research HMSO's Accredited Agents Station. Alice Holt Lodge. Wrecdesham, Farnham, (see Yellow Pages) Surrey GU10 4LH and through good booksellers Contents 4 Introduction 6 How to use the Handbook 8 List of Insect Orders 10 Guide to Insect Larvae 13 Part One: Tree Hosts, Insects and Damage 117 Part Two: Principal Forest Pests 139 References 147 General Index Introduction Most students of the author's generation were brought up on Dr The 'way into’ the book is outlined on page 6. An experienced Neil Chrystal’s Insects of the British woodlands published in user's point of entry will obviously depend as much on the state 1937. Before that foresters had A.T. Gillander’s Forest en tom olo of his knowledge as it will on whether he finds the larva or the gy (1912), and the excellent papers of Prof. R. Stewart damage. MacDougal, many of them published in the Transactions o f the Recognising and dealing with pest organisms, both insects and Royal Scottish Arboricultural Society, were also notable con fungi, do pose real problems to the generalist or practical man, tributions to early knowledge of forest insects. The great as they do indeed to the specialist facing specimens outside his expansion in plantation forestry followed upon the end of the range of particular expertise. There are some 22 000 insects first world war. Many of the earlier crops planted have since recorded in Britain and the late George Gradwell was fond of reached maturity, been felled and replaced and so it is that the remarking that oak forest had about half the insect species forester has, in a short time, gained a great deal of new recorded in Britain associated with it in one way or another. In knowledge about the particular problems associated with the addition there are many species which cannot be run down to different phases of crop life. As new habitats have been created, specific level on a single specimen and many which can only be insect species have found conditions propitious for establish identified by a full time specialist in that particular group. ment and, in some cases, for great increase. I have concerned myself here only with those insects that rely This work is targeted primarily at the field forester and on the tree directly for food - the primary trophic level of the manager, the arboriculturist, the student, the biology teacher or ecologist. field naturalist. It is divided into two parts; the aim of Part One Since the forester’s concern is with the insect stage which is; firstly to provide a quick tool for identification of insects, damages, emphasis must be placed in most cases upon the down to species where possible, or to group where greater immature insect - with the important exception of the precision demands the service of a specialist; secondly to give Coleoptera in which Order the adult quite frequently surpasses some idea of the forest importance or ecological significance of the larva in both longevity and appetite. The List of Insect the species found. Orders (page 8) has been included primarily for quick reference The choice of species included in Part One is not entirely as purposes. For those who wish to tackle the identification of idiosyncratic as it may seem at first! Most of the species are adults 1 would suggest as a next step the key in the Collins Guide common subjects of enquiry whether for the damage they cause to the insects o f Britain and western Europe by Michael Chinery or through some eye-catching characteristic of their appearance, ( 1986 ). behaviour or activity. A few foreign species considered to have a Conventionally larvae are classified into 'types’ within a high pest potential have also been included - as much as a framework of a series of recognisable embryological develop reminder that the flow of exotic pests has been a feature of ment phases. There are both marked variations within the afforestation and is likely to remain so, as it is to provide 'types' as well as adaptations to specific feeding environments. characters by which the species might be spotted on arrival. As a result there are a plethora of shapes, sizes and forms within Part Two deals with the more important pest species, or individual Orders and across a wide range of Orders. For anyone groups of species, and summarises accumulated experience of wishing to enter this rather esoteric field How to know the their patterns of behaviour, site preferences and potential for immature insect by H.F. Chu (1949), is to be recommended. increase. Meanwhile, we shall have to find our own unsteady way 4 through the field by a less sophisticated means - the Guide to trees, with insects names and authorities according to revised Insect Larvae on page 10 (one developed from an original by Kloet and Hincks (published by the Royal Entomological Society Miss J.M. Davies). The guide will certainly be found over of London), up-dated where necessary. It also provides English simplified for more refined tastes and a little latitude is names and a list of the species under their host plants. The third recommended in its use. publication is The use o f chemicals in forest and nursery (due for The references have been chosen in order that the reader can revision as a FC Bulletin), which reflects both up-to-date gain easy access to more detailed information than presented attitudes to the use, as well as choice of, insecticides and other here and to provide a first 'entry' into the literature. Wherever pesticides. possible selection has favoured a late date, English language, and I have to thank all my old colleagues in the Entomology a premium has been put on availability. The four volumes, in Branch, both at the Northern Research Station and at Alice Holt German, by Schwenke (which are to be highly recommended as Lodge, for their help with this publication. They will no doubt be general reference) are here used where no alternative in English involved in future gathering of further information upon the could be found. species covered and upon species yet to demand recognition. It This handbook should be regarded as one of a family of three is equally certain that I have failed to recognise some sources of Forestry Commission publications on insects. This volume aims knowledge, both people and literature. I would therefore to aid recognition and enable the reader to take decisions encourage anyone who feels there have been omissions worthy appropriate to his field. It covers some 280 or so species. A of future inclusion to please make contact with the Entomology second publication, A catalogue of phytophagous insects andBranch of the Forestry Commission’s Research Division. mites on trees in Great Britain by T.G. Winter (FC Booklet 53). provides a list of some 1500 species of insects and mites on DERMOT BEVAN 5 How to use the Handbook The handbook has been divided into two main parts. In addition Part One: Tree Hosts, Insects and Damage there is a list of Insect Orders, a Guide to Insect Larvae, a section Insects have been placed under the HOST TREE GENUS upon which of colour photographs and a list of literature references. they feed (e.g. Quercus - oak. or Larix - larch). Within the GENUS they have been listed according to the PART OF THE TREE on which List of Insect Orders and Guide to Insect they will be found, starting at the top of the tree with LEAF and Larvae working down to ROOTS and finally WOOD. Forests team with insects of many Orders and representatives of all those in the LIST OF INSECT ORDERS on page 8 may be found in Part Two: Principal Forest Pests woodland as well as many species of mites, spiders and other A few species, or groups of species, are dealt with in more detail. arthropods. All combine and interact to recycle basic materials A short summary of their more recent history in Britain is given and nutrients to perpetuate the forest ecosystem. Some breed or and their significance to the management and conservation of feed in or on trees, others depend on herbs, mosses, lichens, the crops upon which they feed is discussed.