Aphid, a short germband insect, displays an embryogenesis different from that of long germband insect species. Furthermore, the development of its parthenogenetic and viviparous embryo is different from that of the embryo resulting from sexual reproduction. To better understand the genetic regulation of this type of embryogenesis, the functions of hunchback in asexual Acyrthosiphon pisum were investigated by parental RNAi. Microinjection of Aphb double-stranded RNA yielded several defective phenotypes. Quantitative real-time PCR analysis revealed that these defects resulted from reduction of Aphb mRNA level in injected aphids. All these results suggested that the hb gene in parthenogenetic and viviparous Acyrthosiphon pisum was involved in abdominal identity suppression and germband growth as its homologue does in sexual insects.