Nymphal behaviour and lerp construction in the mopane psyllid Retroacizzia mopani (Hemiptera: Psyllidae)

Abstract

The nymphal stages of the African mopane psyllid Retroacizzia mopani occur on Colophospermum mopane leaves, feeding on the phloem sap. The emergence of R. mopani coincides with the dry winter period in South Africa, when other trees are leafless. The nymphal stages secrete a scutcheon-like protective covering called lerp. The position of lerps on the leaflets depended on the stage of development of the nymphs. First and second instar nymph lerps were placed along the smaller secondary veins, whereas third, fourth and fifth instars placed their lerps along the main veins on either surface of the leaflet. Nymphs were more common on the adaxial surface than on the abaxial surface of the leaves, suggesting that the lerp offers some form of protection against predators and desiccation. Nymphs do not co-habit the same lerp. Visible damage caused by nymphs and lerps on the host plant includes discolouration of leaflets around feeding sites and occasional curled leaflets.