LACE-BUG GENERA — DRAKE AND RUHOFF 



19 



NEW ZEALANDIAN 

 PAPUAN 8 



Figure 4. — Distribution of tingid genera by faunal subregions. 



Faunal Exchange 



Natural: Numerous genera are shared by two or more faunal 

 subregions (table 2). Distribution of existing species is shown in 

 figure 5 and in table 2. The fossil species are treated in table 1. 



Natural emigration of tingids is a more or less continuous phenom- 

 enon and varies greatly with the biotic potential and vagility of the 

 species. The faunal subregions (figs. 3-5) with land-connections such 

 as the Nearcticand Neotropical, and the Palearctio, Oriental, and Ethi- 

 opian subregions share more genera and species than subregions with- 

 out such connections, such as Soul h America and Australia, and Sout b 

 America and Africa. Some tingid species have disseminated over large 

 areas, although most species are not very active or strong fliers and 

 are rather sedentary in habit. Macroptery and brachyptery are 

 present in a considerable number of species. The brachypterous form 

 has metathoracic or flight wings atrophied or entirely absent. Apterous 

 forms are unknown. 



Imported: Only a few species of Tingidac from the Old World 

 have been introduced across the seas into the Americas through the 

 agency of man, all unintentionally. However, only one transport has 

 occurred in the opposite direction, and that purposely. The latter 

 case concerns the purposeful introduction of Teleonemia scrupulosa 



