Within the insects, the Hemiptera are the most species-rich group of alien
terrestrial invertebrates, followed by the Coleoptera. The hemipterans are mostly
from the suborder Sterrnorrhyncha (aphids and scale insects), which have piercing,
sucking mouthparts, and thus often have severe economic impacts as plant
pests. Half of all the alien Coleoptera in South Africa are biological control
agents (45 species), most of these being from the families Chrysomelidae and
Curculionidae. These groups are widely used as biological control agents of invasive
alien plants, as many species are monophagous (specialised to eat only one plant
Fig. 7.1 The total number of alien terrestrial invertebrate species per taxa in South Africa, with the
number of biological control agents per taxa shown in black
188
C. Janion-Scheepers and C. L. Griffiths
terrestrial invertebrates, followed by the Coleoptera. The hemipterans are mostly
from the suborder Sterrnorrhyncha (aphids and scale insects), which have piercing,
sucking mouthparts, and thus often have severe economic impacts as plant
pests. Half of all the alien Coleoptera in South Africa are biological control
agents (45 species), most of these being from the families Chrysomelidae and
Curculionidae. These groups are widely used as biological control agents of invasive
alien plants, as many species are monophagous (specialised to eat only one plant
Fig. 7.1 The total number of alien terrestrial invertebrate species per taxa in South Africa, with the
number of biological control agents per taxa shown in black
188
C. Janion-Scheepers and C. L. Griffiths