The family Pneumoridae is a group of 17 species distributed along the coast of southern Africa, but also extending northwards into Tanzania and Uganda. Most species occur in transitional habitat comprising mosaics of bush and grassland, with the rest in forests or desert. All species are highly cryptic in appearance and behavior, being color-matched to their particular food plant and rarely noticed except at night when the loud mate location call of the male may be heard ca, 2 km away (van Staaden & Romer 1997
). There are large differences in the morphology and behavior of adult males and females. Only adult males are capable of flight and may be attracted to light, but when approached during the day generally do not fly. In several species males can either develop an inflated abdomen or mate as a flightless alternative male without the anatomy and behavior for sexual signaling (Alexander & van Staaden 1989
). Threatened females and nymphs will drop to the ground and feign death (thanatosis), although nymphs may also jump. The family is significant because individuals possess two forms of ears, providing the first functional evidence for the evolutionary transition from stretch to hearing organs in insects (van Staaden & Romer 1998
Members of the Pneumoridae may be locally abundant, with several species often occupying the same locality. However, there is reason to believe that many populations are threatened or recently extinct.
The species can be distinguished by external characteristics detailed in the most recent revision of this group by Dirsh (1965; key to the genera and species
), although there is now some doubt as to the authenticity of several taxa (see "Discussion of phylogenetic relationships").