Alternative common names:
Cypress aphid is a blackish-brown, sap-sucking insect that infests the stems of some hedging conifers. It is on the list of the world’s 100 most invasive species. It is reported to cause significant damage and to have been recently introduced to parts of Europe, Africa, South Americaandthe Middle East. It is commonly seen in colonies along the twigs of infested trees.
Where does this species come from?
What is its invasive status in South Africa?
NEMBA 2020 Category 1b.
Where in South Africa is it a problem?
How does it spread?
Through the flight of the winged forms, which are produced a few times each year in response to overcrowding and environmental cues. It is also transported on imported plant material.
Why is it a problem?
It affects the tree by sucking sap from the twigs, which causes yellowing to browning of the foliage on the affected twig. It damages commercial and ornamental plantings.
What does it look like?
Description: Cypress aphid is a brownish, soft-bodied insect with blackish markings diverging back from the thorax, often with a grey, waxy coating. It is about 2.4mm long. Adults are winged or wingless. They often occur with several young (nymphs), which they produce rapidly.
Habitat: Host, natural forests, planted forests. It is commonly seen in colonies along the twigs of infested trees.
Breeding: In summer, only females are present and reproduce parthenogenetically (without mating), giving birth to live young. There are two adult forms – winged and wingless. As cooler weather approaches, both males and females are found, and eggs are produced instead of live nymphs. The eggs are laid in rough areas on twigs and foliage where they overwinter. Several generations are produced per year, with a single generation living for about 25 days during the peak host plant growing season. In warm regions such as Africa, the aphid does not overwinter as an egg; instead parthenogenetic reproduction continues all year.