S. vayssierei is the only known hypogeal (below-ground) species in the family Stictococcidae (Tindo et al., 2006). It is a Sternorrhynchan with incomplete metamorphosis. Ngeve (2003a) described the males as rare and the more common adult female as dark-red, circular and flattened. In contrast, Tindo et al. (2006) described the adult females as brown and the first and second instars as purple-red.
Related crop
- Dioscorea
- Manihot esculenta
Related invasive species
- Dieback
Related Farm Practice
- Cuttings
- Damage
- Feeding
- Host plants
- Hosts
Young feeder roots of germinating cassava cuttings are attacked by both the nymphs and adults of S. vayssierei. The feeding damage causes premature leaf-fall, wilting, tip dieback and ultimately results in death. Those plants that are not attacked until later develop normally and tuberize, however, they exhibit small mature tuberous roots and become covered in scales, making them unsuitable for sale (Ngeve, 2003a).
S. vayssierei feeds on the root system of cassava (Manihot esculenta), affecting tuber formation of the plant (Williams et al., 2010);however, there is evidence to suggest either polyphagy or involvement of more than a single scale species (Tindo et al., 2006). Sixteen plant species belonging to 13 families have been identified as hosts of S. vayssierei in the Congo basin (Tindo et al., 2009;see Host Plants/Crops Affected), but this may reflect the involvement of more than one species, as yet unidentified. It is thought that native Dioscorea species may play an important role in maintaining Stictococcus populations during long fallows and in secondary and primary forests. Cassava, an exotic plant in this area, may contribute to the growth of S. vayssierei in fallows less than 8 years old (Tindo et al., 2009).