424 



CONNECTICUT GEOL. AND NAT. HIST. SURVEY. 



[Bull. 



plants. Even among- species which always breed on a single host 

 plant, a general dispersal of individuals usually takes place. Fol- 

 lowing the time of emergence and mating, individuals of Tropi- 

 dosteptes cardinalis Uhler, Lopidea staphyleae Knight, and others, 

 have been observed to migrate from their host plant to shrubbery 

 in the general vicinity; from thence they doubtless become dis- 

 persed over wider territory and to new plants, although in the 

 normal course of their life, eventually returning to suitable growth 

 of the preferred host plant for the purpose of oviposition. 



As regards the number of species, the Miridae by far outnumber 

 all other families of Heteroptera. In the Palearctic region, where 

 the total number of Heteroptera is best known,* one thousand 



Fig. 48. A phylogenetic tree of the subfamilies of the Miridae. 

 by Dr. H. H. Knight. 



Drawing 



seventy-eight species are listed for the family Miridae while all 

 other families of Heteroptera combined total but 2,486 species. 

 The Oshanin Katalog enumerates 5,476 species of Heteroptera and 

 Homoptera for the Palearctic region, from which it may be seen 

 that the family Miridae forms nearly one-fifth of all the species 

 of Hemiptera listed. This is perhaps a fair indication of what 

 may be expected for the relative number of species of Miridae in 

 North America, after our fauna has been more systematically 

 collected and worked. 



After considerable study of the arolia and genital structures in 



* Katalog der palaarktischen Hemipteren (Heteroptera, Homoptera- 

 Auchenorhyncha iind Psalloidae). 1912. 



