Currently about 5500 thrips species are described worldwide. A few of them are known as serious crop pests and vectors of bacterial, fungal, and viral diseases. Thrips species show different lifestyles ranging from solitary forms to eusocial species. Reproduction mode is either arrhenotoky or thelytoky. This study represents results on different aspects of thrips biology including morphological and developmental investigations. The aim was to describe (with the help of different methods) the thrips species process of reproduction and to outline the underlying morphological and developmental mechanisms. Data on the sex ratio of different thrips species, copulation and oviposition behaviour, and morphology of the genital organs were collected from Frankliniella occidentalis, Echinothrips americanus, and Suocerathrips linguis. Life tables were determined for F. occidentalis and E. americanus and data on the tospovirus-transmitting thrips species Frankliniella fusca and F. occidentalis were also included. The progenesis of thrips describes the differentiation of the genital organs during the larval and metamorphic stages of F. occidentalis, E. americanus, and S. linguis. Embryogenesis data on egg morphology, duration of embryogenesis, and mortality rate of F. occidentalis and S. linguis were collected and histological techniques and video documentation were used to describe the embryogenesis of both species as representatives of the two suborders Terebrantia and Tubulifera. The results of this study represent useful information to answer questions, which are connected with the development of thrips as pests, the growing progress of resistance of these species against insecticides, and the development of suitable pest management strategies. Knowledge about morphology and developmental processes as well as the resulting behaviour and adaptations help to clarify, why some species are highly adapted to their host plant and while others show a broad host plant spectrum, why only a few thrips species act as tospovirus-transmitters, and which are the basics of the development of different social lifestyles within the order Thysanoptera.