Biology and Host-Range of Boreioglycaspis melaleucae (Hemiptera: Psyllidae), Potential Biological Control Agent for Melaleuca quinquenervia (Myrtaceae)

Abstract

The Australian broad-leaved paperbark tree, Melaleuca quinquenervia S. T. Blake, has become a serious weed in southern Florida. Surveys in Australia identified a sap-sucking psyllid, Boreioglycaspis melaleucae Moore, as a promising biological control agent. We collected this psyllid in Queensland and northern New South Wales; it has also been recorded from Western Australia and the Northern Territory. Eggs are attached to leaves by a pedicel and most hatch within 18 d of oviposition. Nymphs congregate on leaves and secrete white, flocculent threads that can completely cover the immatures in the 3rd-5th instars. Nymphs are parasitised by Encyrtidae and predated by a coccinellid and lygaeid. Both adults and nymphs feed on the sap of M. quinquenervia, but nymphs cause the most damage and high numbers kill potted M. quinquenervia saplings in laboratory cages. Development from egg to adult takes 28-40 d, and females lay an average of 78 eggs. Literature records and our collections indicate that the field host-range of B. melaleucae is restricted to M. quinquenervia and 4 of its close relatives. This psyllid oviposited on 27 of the 42 plant species tested. However, immatures only developed to the adult stage on M. quinquenervia, M. nodosa (Gaertner) Smith, and M. viridiflora Solander ex. Gaertner.