Extraction of DNA from whole aphids, in combination with random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) (Williams et al. 1990) markers can detect interspecific and intraspecific genetic variation (Black et al. 1992; Cenis et al. 1993). However, these techniques entail destructive sampling of fresh or preserved specimens. To allow experimental replication from a single sample while preserving the same aphid for morphometrical or karyotyping analyses, we describe a technique for RAPD-PCR using DNA from single aphid embryos. We evaluated the usefulness and reliability of single-embryo analysis, using four species of our laboratory colonies, namely Acyrthosiphon pisum (Harris), Aphis fabae Scopoli, Aphis frangulae group, and Aphis gossypii Glover.