Leaf purpling on the opposite side of the lerps, chlorosis, leaf necrosis, and defoliation.
Clusters of dark brown, scalloped shell-like structures (lerps). The lerps increase in size with each instar. Immatures, ranging from 0.24 mm to 1.7 mm, remain under the lerps until emerging as young adults. Adults are 3 mm to 4 mm in size. The eggs are reddish brown in colour, smooth and ovoid in shape. Nymphs are brown to yellowish-brown, while adults are orange with small brown spots on the thorax and banded, striped abdomens (Makunde et al. 2023).
Adults lay eggs in clusters on the leaf surface and eggs incubate for 11 days. The nymphs develop under brown scalloped shelters for 23 days, and females reach reproductive maturity 2 days after eclosion, laying an average of 16 eggs. The total life cycle from egg to adult death spans 37 days (Makunde et al. 2023).
Although not much is known, the parasitic wasp Psyllaephagus bliteus, known to parasitize other lerp-forming psyllids, has been found parasitizing the shell lerp psyllid. Planting resistant material is also a potential management strategy.
Makunde PT, Slippers B, Bush SJ, Hurley BP. 2023. Biology of the invasive shell lerp psyllid, Spondyliaspis cf. plicatuloides (Froggatt) (Hemiptera: Aphalaridae). African Entomology 30: e13747. Bush SJ, Slippers B, Neser S, Harney M, Dittrich-Schröder G, Hurley BP. 2016. Six recently recorded Australian insects associated with Eucalyptus in South Africa. African Entomology 24:539-544.
