none This review presents a variety of data relevant to embryonic patterning in hymenopterans and dipterans. The aim is to define common traits as well as differences that from the evolutionary point of view might merit further study. The individual chapters review molecular data, expression patterns, perturbation experiments and some steps in normal oogenesis and embryogenesis, with evolutionary implications mentioned only in passing. In a closing chapter, the - still very patchy - data are summarized under phylogenetical aspects. The species considered come from the hymenopteran families Apidae and Ichneumonidae and from the dipteran families Psychodidae, Scatopsidae, Sciaridae, Culicidae, Phoridae, Calliphoridae, Muscidae and Drosophilidae. Documentation; Publications; Life cycle and development; Development; Genetics; Evolution Diptera; Hymenoptera; Literature review; Embryo development; Patterning mechanisms; Molecular genetics; Variation; Embryonic patterning mechanisms, review