Book excerpt: A revision and the first phylogenetic analysis of the widely distributed plant bug genus Tytthus is presented. All 24 species of this genus, including five described as new, prey exclusively on planthopper (Delphacidae) eggs, making them of great importance on agricultural monocots. Two species have been used successfully in biocontrol programs to suppress populations of sugarcane delphacid on sugarcane and brown planthopper on rice. All species of Tytthus are relatively small, but the tiny brachypterous males of one species, ranging from 1.08?1.30 mm long, rank it as possibly the world?s smallest known plant bug. Members of this genus are found in nearly all biogeographic regions, including 18 restricted to the Nearctic and Neotropics and three from the eastern Oriental and Indo-Pacific regions. There are also two Holarctic and one circumtropical (Afrotropical, Neotropical, and Oriental) species. A hypothesized relationship with several Nearctic plant bug genera suggests a New World origin for this group of important predatory bugs.