ENTOMOLOGICAL LITERATURE 7 



Insect Pests of Farm, Garden and Orchard, by 

 E. D. Sanderson, John Wiley & Sons. 



Insects injurious to Vegetables, by F, H. Chitten- 

 den, Orange Judd Co. 



Manual of Vegetable Insects, by C. R. Crosby 

 and M. D. Leonard, Macmillan Co. 



Insects and Insecticides, by C. M. Weed, Orange 

 Judd Co. 



^ Economic Entomology, by J. B. Smith, J. B. Lip- 

 pincott Co. 



Insects Injurious to the Household and Annoy- 

 ing to Man, by Glenn W. Herrick, Macmillan Co"! 



Manual for the Study of Insects, by J. H. Com- 

 stock, Comstock Pub. Co. 



NUMBER OF INSECTS 



Over 350,000 now known and described. Esti- 

 mated to be from two to ten millions. Over 50,000 

 from North x\merica. Several thousand are being 

 described each year. 



GROUPS CONTAINING THE PRINCIPAL IN- 

 JURIOUS INSECTS 



1. Ortlwptcra — Crickets, grasshoppers, cock- 

 roaches, et al. 



2. Hcmiptcra — aphids, scale insects, chinch bugs, 

 et al. 



3. Lepidoptera^ — butterflies and moths. 



4. Dipt era — flies. 



5. Cole opt era — beetles. 



6. Hymenoptcra — sawflies, bees, ants, wasps, 

 etal. 



Again, all of the injurious insects may be gath- 

 ered into two great groups, dependent upon the 

 structure of their mouthparts. These are the suck- 

 ing and biting insects. 



