'0 J . Id 



PREFACE. 



The absence of any work treating exclusively of British species has been 

 felt more keenly during recent years in the case of the Ichneumonidae 

 than in that of any other branch of our native fauna ; firstly, because all 

 ^ those Orders of insects which entomologists most generally study have 

 J been already adequately monographed, some of them over and over again, 

 and secondly, because all the remaining groups which have not yet formed 

 "^ the subject of indigenous comprehensive works, such as the smaller 

 L^ hymenopterous, dipterous and neuropterous families, are so minute in 

 d size and obscure of definition that few students have experienced incon- 

 venience from the deficiency. In the Ichneumonidae, however, the large 

 size and handsome coloration of the majority of its species, together 

 ^vith their ubiquity and interesting economy, have led many collectors to 

 I. accumulate large numbers of specimens, and their disgust at discovering 

 ^ the almost entire impossibility of satisfactorily determining their captures 

 has usually led them to at once cease collecting these insects ; hence the 

 <^ scarcity of material upon which to work and the extreme rarity or any 

 oinote or reference to them in serials which teem with those upon other 

 {^Orders of insects. What Curtis said so long ago (B.E. 120), " the vast 

 -frnumber of species, together with the difficulty of seizing distinctive 

 ^characters, has either caused this family to be totally neglected or but 

 imperfectly understood in most countries, but in none more so than in 

 our own," is still substantially true to-day. 



From the earliest times, I have experienced much affection for these 



_j; elegant and sagacious insects, and one night in August, 1898, I determined 



tto devote myself to their study. The short time which has since elapsed 



vwill, it is hoped, be sufficient excuse for those inaccuracies and imperfec- 



;-tions which the present volume doubtless contains, but it has been 



' j^ought expedient to present what is already known of our species rather 



'^lan to delay its publication for an indefinite period, and, by so doing, to 



Jat once engage the interest and co-operation of those who, failing some 



-^ext book however imperfect, would never have thought of commencing 



^ the study. 



•P f^.nncxC 



