New Zealand Rubus Rust-Hamaspora australis

This rust fungus is native to New Zealand where it is not especially damaging and control of this rust is not considered necessary. In New Zealand introduced species of Rubus e.g., blackberry and boysenberry are attacked by other rust fungi that do not produce these distinctive thread-like telia (Hood, 1985).

Hamaspora australis G. Cunn 1930

Uredinia subepidermal, hypophyllous, sparse, minute, brown, seated on pallid spots, 0.5-1.0 mm diam; paraphyses absent; urediospores globose, subglobose, ovoid, obovoid, ellipsoid, yellow, 19-29 × 14-22 µm, wall 1-2 µm thick, verrucose, without distinct germ pores.

Telia hypophyllous, scattered, or caespitose, filiform, white or pale yellow, seated on definite pallid spots, elliptical, 0.5-1.0 mm diam, pulverulent; teliospores obclavate to acicular, hyaline, 2-5 septate, mostly 3-5 septate, 55-218 × 16-24 µm long, apical cell 2-17 × 17-2.5 µm.

See Cunningham (1931) and Monoson (1969) for a more detailed description.

Host range: Uredinial and telial stage: Rubus australis G. Forst. Rubus cissoides A. Cunn. Rubus schmidelioides A. Cunn. Rubus schmidelioides var. subpauperatus (Cockayne) Allen Rubus squarrosus Fritsch

Geographic distribution: All host species of H. australis occur only in New Zealand and this rust species appears to be indigenous to New Zealand.

This rust species appears as yellow to brown spots, about 3 mm diam, on both surfaces of leaves. In the middle of the spots are group of white to yellow thread-like telia, up to 1-2 cm or more long, lying across the lower leaf surfaces (Hood, 1985).

References:

Cunningham, G. H. 1930. Seventh supplement to the Uredinales and Ustilaginales of New Zealand. Trans. & Proc. New Zealand Inst. 61: 402-418.

Cunningham, G.H. 1931. The Rust Fungi of New Zealand together with the Biology, Cytology and Therapeutics of the Uredinales. John McIndoe, 261 pages.

Hood, I.A. 1985. Rust fungi in native forests. For. Pathol. N. Z. 14: --.

McKenzie, E.H.C. 1998. Rust fungi of New Zealand--an introduction, and list of recorded species. New Zealand J. Bot. 36: 233-271.

McKenzie, E.H.C., and Dingley, J.M. 1996. New plant disease records in New Zealand: miscellaneous fungal pathogens III. New Zealand J. Bot. 34: 263-272.

Monoson, H.L. 1969. The species of Hamaspora. Mycopathol. Mycol. Appl. 37: 263-272.

Nomenclature

Specimens in BPI

Additional distribution data

Suggested citation: Yun, H.Y. Systematic Mycology and Microbiology Laboratory, ARS, USDA. . Invasive Fungi. New Zealand Rubus Rust-Hamaspora australis. Retrieved November 21, 2009, from http://nt.ars-grin.gov/sbmlweb/fungi/index.cfm .