PREFACE TO THE FIRST EDITION vii 



pinned in a corner of the box as a guard against mites, the great enemy 

 of the dipterist as of the entomologist in general. 



The chief season for collecting in this country is from March till 

 October, the sunny forenoon being the best time. Windy days are very 

 unproductive. Even well-known and good localities are sometimes a 

 blank, from causes we do not know, for flies seem very capricious in their 

 habits. But, like other creatures, they have special haunts where they 

 may usually be found at the proper season, and where they may be 

 expected to occur if carefully searched for. Considerable experience in 

 their habits and localities is needed by the collector. Generally speaking, 

 umbelliferous plants, also bramble, hawthorn and ivy bloom seem to 

 be most attractive. Flies often settle upon gate-posts, railings, and tree- 

 trunks, especially if wounded or decayed. Others frequent salt-marshes 

 and swamps, ponds and river-sides; whilst heath-lands, sheepruns, bare 

 hot sandy areas and commons attract others. Horse and cattle 

 droppings and decomposing animal and vegetable matter are well- 

 known baits for many species. Others attack living animals, not 

 excepting man ; and certain flies prey on insects and spiders. Should 

 horses or cattle be approached for the purpose of taking flies, much 

 care must be exercised, as a net will generally stampede them ; it is 

 difficult to employ it to advantage under such conditions. 



This little book has received the kind encouragement of many 

 entomologists, among whom I may mention Professor Nuttall and 

 Mr Warburton, both of Cambridge. Much practical help in the 

 selection of species, and information as to types selected and their 

 larvae, has been afforded by the kindness of Professor Theobald, whose 

 assistance, it is hoped, has added greatly to the utility of this book. 

 Thanks are also due to Mr Harwood, of Sudbury, Suffolk, for some of 

 the fine specimens of diptera which he has furnished for the photographs 

 herewith presented. It has not always been possible to do them justice, 

 owing to the difficulties previously noted as besetting the photographer. 

 Mr H. Waddington kindly supplied some fine microscopic slides. 

 The author's brother, Mr N. D. F. Pearce, has also helped with the 

 illustrations, as to the success of which the reader must be left to 

 judge. Acknowledgement has been made in every case, it is thought, 

 where help has been received: and if this effort is successful it is 

 hoped that it may be some day supplemented by a further series of 

 pictures, to fill a few gaps that were unavoidable in the present volume. 

 The life history (ovum, larva, pupa) of many of the species shown is 



