Well, here is my abstract submission for the 2008 Hawai'i Conservation Conference July 29-31, 2008
Brush cherry (Eugenia paniculatum): a new host for ohia rust (Puccinia psidii). David Simmons, Chris Kadooka and Janice Uchida. Department of Plant and Environmental Protection Sciences.
Puccinia psidii was first found on potted ohia (Metrosideros polymorpha) on Oahu and has devastated rose apple (Syzygium jambos). Brush cherry (Eugenia paniculatum), a popular ornamental plant, was found infected with rust in Kamuela. This would be a new host record for P. psidii in Myrtaceae. Our objective was to confirm the identity of the rust. Typical urediniospores of P. psidii were found on brush cherry. In 2007, molecular analysis showed that only one strain of eight known strains was present in Hawaii. Molecular analysis showed that the brush cherry rust is similar to the other P. psidii samples collected in Hawaii. Each strain is believed to attack different hosts based on early studies. The Hawaii strain causes severe disease on rose apple, spores from brush cherry were used to inoculate rose apple, and abundant lesions formed. Morphological, molecular, and pathological results support the discovery of P. psidii on a new host, Eugenia paniculatum. Researchers have noticed a cecidomyiid larvae feeding on rust urediniospores. Heavy feeding can occur and interferes with efficient spore collection needed for research. These larvae were reared and adults were successfully obtained, and sent to the Hawaii Department of Agriculture for identification.
I will be giving a presentation on the above ^_^ at the Hawaii Convention center.
I'll add more info later...