Citrus greening is a bacterial disease vectored by the invasive Asian citrus psyllid (ACP). The disease is spread primarily by two species of psyllid insects. The mopane tree also serves as a host plant for the mopane psyllid "Retroacizzia mopani". Its use expanded following the widespread defoliation of Leucaena by psyllid in the 1980s. These features distinguish it from the superficially similar African citrus psyllid. It can also consume Asian citrus psyllid, broad mites, and other herbivorous mites. The psyllid was previously introduced into Florida in 1998. The psyllid individuals feed on the knotweed's meristem. In Southern California, an insect called tipu psyllid Platycorypha nigrivirga has invaded several trees. It is the preferred host to the insect pest "Diaphorina citri", the citrus psyllid. Psyllid nymphs are found on new shoots of citrus trees. This psyllid is the vector for the citrus greening disease. The disease is spread through an insect vector, the Asian citrus psyllid. Psyllid fossils have been found from the Early Permian before the flowering plants evolved. The rectangular-lerp forming psyllid "Glycaspis siliciflava" eats only this species.