The distribution and host-plants of the species of Quadraspidiotus (Homoptera : Diaspididae) in Australia

Abstract

Inspections made in the pome fruit orchards of Australia during 1961-66 showed that four species of Quadraspidiotus, viz. Q. perniciosus (Comst.), Q. ostreaeformis (Curt.), Q. pyri (Licht.), and Q. lenticularis (Lind.) occurred on pome fruits and other deciduous plants. Quadraspidzofu.r perniciosus, which is a pest in most of the orchard districts of Queensland, New South Wales, Victoria, South Australia, and Western Australia, also occurs in Tasmania, while Q. ostreaeformis occurs in southern Tasmania, Victoria, and South Australia. The other two species (Q. lenticularis and ,Q. pyri) are at present confined to South Australia and Tasmania respectively. The most widely distributed species, Q. perniciosus osw, is also, economically, the mcst important because its presence on fruit may cause it to be rejected by quarantine authorities at certain ports of entry overseas. Though Q. ostreaeformis and Q. pyri are regarded as minor pests in orchards, Q. lenticularis is at present of no economic significance.