﻿STINK BUGS, GENUS MECIDEA — SAILER 475 



to include one North American species that has a variety in South 

 Africa. 



Several well-established cases of insect genera that have species 

 distributed among the arid regions of North America, South America, 

 and Africa are known, though in several instances genera so listed in 

 the past do not bear critical scrutiny. It is to be expected that the 

 number of genera exhibiting this distribution will be small, since any 

 relationship shown by these desert floras and faunas must be of very 

 ancient origin, and few genera would be expected to survive the 

 prolonged effects of divergent evolution. This view is amply supported 

 by a large number of tribes and subfamilies that exhibit either this 

 distribution pattern or some variant of it. 



Chopard (1938), in a chapter on the habitats of Orthoptera, discussed 

 such relationships and cited 3 subfamilies that contain genera in the 

 desert regions of 2 or more continents. Uvarov (1938) used many of 

 the same genera in an extensive paper on the subject; however, he 

 treated them in tribal rather than subfamily groupings. Uvarov 

 (1937) also mentioned the mecopterous family Bittacidae, which 

 contains 2 allied flightless genera: Apterobittacus, which occurs in 

 California; and Anomalobittacus, which is known from South Africa. 

 The homopterous genus Orgerius, of the family Dictypharidae, has 

 been listed by several authors and most recently by Metcalf (1946) as 

 having about 20 Mediterranean species and at least 4 species in the 

 western United States; however, Ball and Hartzell (1922) expressed 

 the opinion that the Old World species belonged to a different genus 

 and Dr. P. W. Oman, who has examined specimens from both regions, 

 confirms this view. Nevertheless, the tribe Orgeriini remains a good 

 example of the distribution pattern in question. 



At the generic level a termite genus, Amitermes, appears to provide 

 a distribution picture that is in many respects similar to that of the 

 tribe Mecideini. Like Mecideini it is predominantly Australasian but 

 contains species that are widely distributed in the arid or semiarid 

 parts of southwestern North America, South America, Africa, and 

 Asia. This genus was discussed at some length by Hill (1942). 

 Cockerell (1932) has shown that a genus of bees, Hesperapis, occurs in 

 the arid districts of the southwestern United States and under similar 

 conditions in South Africa. 



Another genus that has a marked preference for arid or semiarid 

 regions is Apiocera, in the dipterous famfly Apioceridae. Cazier 

 (1941) has provided a generic review of this family and a discussion of 

 the distribution of the family and its 4 genera. Three of the genera 

 have a restricted one-continent distribution; however, the fourth, 

 Apiocera, contains 13 known Australasian species, 1 from South 

 Africa, 2 from Chile, and 20 from North America. 



