Abstract:

Melaleuca quinquenervia, native to Australia, is an introduced, invasive, pest tree in south Florida USA.  Expansive monocultures replace native habitats such as in the Everglades.  Host-range tests of Fergusonina turneri, a bud-galling fly, and its obligate nematode Fergusobia quinquenerviae Davies & Giblin-Davis (Tylenchida: Sphaerulariidae) were conducted in a quarantine greenhouse, Gainesville, FL, USA from August 2000 through January 2002.  Tests focused on closely related species that produce buds similar in size and morphology to M. quinquenervia, and for biosafety reasons, 8 native Florida Myrtaceae not closely related.  Other myrtaceous and non-myrtaceous that produced buds that appeared suitable for F. turneri oviposition and nemaposition were screened also.  Fergusonina turneri and Fergusobia quinquenerviae completed development only on Melaleuca quinquenervia in quarantine.  The Technical Advisory Group (TAG) to APHIS approved the insect for release in May 2004.  If APHIS concurs and issues a permit for release, the fly and nematode have the potential of directly impacting melaleuca’s copious seed production and greatly enhancing the effectiveness of the two previously released leaf-feeding agents, Oxyops vitiosa Pascoe (Coleoptera: Curculionidae) and Boreioglycaspsis melaleucae Moore (Hemiptera: Psyllidae).  Host-range tests of Lophodiplosis trifida, a stem-galling fly, were initiated in October 2003 and are ongoing.  Preliminary data indicate this species oviposits on nontarget myrtaceous species under caged, no-choice conditions in the greenhouse, but cannot complete development on any species except M. quinquenervia.