CONTENTS. 



Page. 



Introduction 13 



Previous work in the practical handling of natural enemies of injurious insects. . 16 



Early practical work 17 



Permitting the parasites to escape 18 



The transportation of parasites from one part of a given country to another 



part 20 



The transfer of beneficial insects from one country to another. 23 



Early attempts 23 



The Australian ladybird (Novius cardinalis Muls.) in the United 



States 24 



Novius in Portugal 27 



Icerya in Florida 28 



Novius in Cape Colony 28 



Novius in Egypt and the Hawaiian Islands 28 



Icerya in Italy 29 



Icerya in Syria 29 



The reasons for the success of Novius 29 



Introduction of Entedon epigonus Walk, into the United States 30 



Other introductions by Koebele into California 31 



International work with enemies of the black scale 31 



The Hawaiian work 34 



An importation of Clerus from Germany 36 



Marlatt's journey for enemies of the San Jose scale 36 



The parasites of Diaspis pentagona Targ 38 



The work of Mr. George Compere 38 



Work with the egg parasite of the elm leaf -beetle 39 



Work with parasites of ticks 41 



Mr. Froggatt's journey to various parts of the world in 1907-8 42 



Other work of this kind (by Berlese; by Silvestri; in Algeria; in the 



Philippines; by De Bussy; in Peru) 44 



Early ideas on introducing the natural enemies of the gipsy moth 47 



Circumstances which brought about the actual beginning of the work 49 



An investigation of the introduction work 50 



Narrative of the progress of the work 54 



Known and recorded parasites of the gipsy moth and of the brown-tail moth. . . 84 



Establishment and dispersion of the newly introduced parasites 94 



Disease as a factor in the natural control of the gipsy moth and the brown-tail 



moth '. 97 



Studies in the parasitism ^feiative insects 102 



Parasitism as a factor in insect control 105 



The rate of increase of the gipsy moth in New England 109 



Amount of additional control necessary to check the increase of the gipsy moth 



in America 114 



The extent to which the gipsy moth is controlled through parasitism abroad 117 



Parasitism of the gipsy moth in Japan 120 



Parasitism of the gipsy moth in Russia 123 



Parasitism of the gipsy moth in southern France 129 



5 



