aphid are small , soft-bodied insect pets also know as ' plant lice ' as they feed on the sap of phloem vessels in plants. In aphids, both sexual and asexual reproduction take place but reproduction is typically parthenogenetic.
Parthenogenesis is a form of asexual reproduction found in femaies, where growth and development of embryos occur without fertilisation by a male.
It occurs in many invertebrates such as aphids, ants, wasps, bees and rotifers.
Aphids are parthenogenetic for most of their lives. They are both parthenogenetic and viviparous during spring and summer and during these seasons, all aphids are female.
In spring, an aphid egg hatches to produce a female aphid or nymph. This female soon begin producing new, wingless females by what is known as viviparous parthenogenesis or giving birth to live young rather than laying eggs (see Figure 9.25). Aphids are prolific and a wingless female can produce up to 12 offspring a day.
Later in the year, some of the aphids develop into males as well as females so that sexual reproduction takes place. In autumn, adult females lay fertilised eggs which overwinter to hatch the following spring and the cycle begins again.