The Nearctic is generally interpreted as that part of the Americas north of the Caribbean and north of the USA/Mexican border. However, sub-tropical southern Florida has strong faunal connections with the Caribbean, and parts of northern Mexico share faunal similarities with Southwestern USA. Despite this, there is a remarkable discontinuity in the region of the USA/Mexican border, in that the diverse and worldwide genus Thrips appears to have almost no native species south of this border.
The Neotropics is generally considered as that part of the Americas south of Florida and south of the USA/Mexican border. However, southern Florida is susceptible to invasion by species from the tropics, and the thrips fauna of the drier northern parts of Mesoamerica is substantially different from the wet tropical areas further south. Similarly, the thrips fauna of southern South America appears to be different from that of the tropical areas.
The palaearctic region extends from the Atlantic coasts of western Europe to Japan and much of China. Some northern species are known to range across this vast area, but the thrips fauna of the northern palaearctic region differs considerably from that of the southern areas around the Mediterranean and north Africa. These southern palaearctic elements in the Sahel zone extend across Iran to northern India.
The Afrotropical region comprises several different elements, although some thrips species have extensive ranges, for example from Angola to Ethiopia. The tropical fauna seems to be widespread across the continent, but southern South Africa has a different thrips fauna from that of the tropics. The African thrips fauna remains poorly known.
This region has one of the most diverse thrips faunas in the world, with the fauna of Southeastern Asian countries such as Vietnam and Myanmar being largely unexplored, and much of the older descriptive taxonomy from Java and Sumatra being unreliable. In contrast, there have been extensive studies on the thrips fauna of some parts of India, and it is clear that the northern fauna extending along the mountains to southern China has relationships to the southern Palaearctic fauna rather than to the fauna of the tropical zone.
Australia has an extensive endemic thrips fauna, but the northern part of the continent shares many species with Indonesia. Unfortunately, the highly diverse fauna of New Guinea is almost completely unstudied. New Zealand and the Pacific Islands have a few endemic species, but the thrips faunas of these areas are usually dominated by introduced species.