TABLE OF CONTENTS 



PAoa 



Introduction • ^ 



List of Plates xix 



List of Text Illustrations xxi 



Order Hymenoptera * 



Table of Suborders and Superfamilies .... 2 



The True Bees (Superfamily Apoidea) ... 4 



Life History of a Bumble Bee (Bombus fervidus) . 12 



Wasps '^ 



The Solitary Wasps (Superfamily Sphecoidea) . . 18 

 Life History of a Digger Wasp (Sphecius spectosus 



Say.) 22 



The Social Wasps and Their Allies (Superfamily 



yespoidea) 25 



Typical Life History }} 



Life History of a Parasitic Wasp (L(Blius trogoder- 



matis) 34 



The Ants (Superfamily Formicoidea) ... 37 



Typical Life History 48 



The Proctotrypoid Parasites (Superfamily Proctotry- 



poidea) 49 



The Gall-Flies (Superfamily Cynipoidea) ... 53 



The Chalcis Flies (Superfamily Chalcidoidea) . . 56 

 Life History of a Chalcis Fly ( Euplectrus comstocki 



How.) 57 



The Ichneumon Flies (Superfamily Ichneumonoidea) 61 

 Life History of an Ichneumon Fly ( Pimpla inqui- 

 sitor) 64 



The Horn-Tails (Superfamily Siricoidea) ... 69 



Life History of a \\ovn-l 2a\ ( Phylloecus integer) . 71 



The Saw-Flies (Superfamily Tenthredinoidea) . . 73 

 Life History of the Pear Slug ( Eriocampoides 



limacina) 7^ 



The True Flies (Order Diptera) 79 



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