Kauaʻi record · KCA-FUNGI-000004
Myrtle rust / guava rust / ʻōhiʻa rust
Austropuccinia psidii
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About Myrtle rust / guava rust / ʻōhiʻa rust
Myrtle rust / guava rust / ʻōhiʻa rust is a Kauaʻi-relevant fungal record. Role: Rust pathogen of Myrtaceae. Associated habitat or substrate: Myrtaceae foliage, shoots, flowers and fruit.
Kauaʻi evidence
CTAHR Forestry Extension identifies broad Myrtaceae host range and Hawaiʻi concerns.
Names and classification
- Scientific name
- Austropuccinia psidii
- Common names
- Myrtle rust / guava rust / ʻōhiʻa rust
- Family
- Sphaerophragmiaceae
- Order
- Pucciniales
- Record type
- species
Kauaʻi occurrence and status
- Kauaʻi occurrence
- Established in the Hawaiian Islands; Kauaʻi-specific current distribution to be resolved
- Origin
- Introduced pathogen
- Conservation status
- Forest and horticultural disease concern
- Evidence date
- 2026-09-13
- Evidence limits
- Occurrence strength is explicit; statewide/Hawaiian checklist evidence is not treated as a precise Kauaʻi site record.
Habitat and ecology
- Habitats
- Myrtaceae foliage, shoots, flowers and fruit
- Ecological role
- Rust pathogen of Myrtaceae
- Food and resource needs
- Rust pathogen of Myrtaceae
- Reproduction
- Spore production or clonal/mycelial growth; source-specific details vary
- Shelter
- Myrtaceae including ʻōhiʻa, guava, Eucalyptus, Eugenia, Melaleuca and Syzygium
- Substrate
- Myrtaceae including ʻōhiʻa, guava, Eucalyptus, Eugenia, Melaleuca and Syzygium
Threats and conservation
- Threats
- Threat to susceptible native and introduced Myrtaceae; genotype changes remain a concern
- Conservation actions
- Retain observations with provenance; protect sensitive sites; support specialist review; apply disease hygiene and management protocols when relevant
- Monitoring
- Record substrate, host, microhabitat, date, rainfall/moisture, visible morphology, photos, specimen/voucher status, DNA status, and attendant biota
- Data gaps
- Kauaʻi voucher status, precise taxonomic confirmation, microhabitat, host/substrate specificity, abundance, and seasonal pattern need expansion.
Process and seasonal context
- Seasonal timing
- Often moisture- and substrate-dependent; Kauaʻi timing requires repeated observation
- Seasonal description
- Myrtle rust / guava rust / ʻōhiʻa rust is a Kauaʻi-relevant fungal record. Role: Rust pathogen of Myrtaceae. Associated habitat or substrate: Myrtaceae foliage, shoots, flowers and fruit.