In May 2001, an international team of pathologists and entomologists undertook a Saccharum pest and disease survey around the perimeter of PNG. This paper reports on pest and disease observations in Saccharum officinarum, S. spontaneum, S. robustum, S. edule and in hybrid sugarcane. Ramu stunt was widespread. Other common diseases were chlorotic streak, orange rust, yellow spot, Fiji and Ramu streak. Specimens of Fiji disease with purple instead of pale green galls were found at Alotau; this is the first known report of purple Fiji disease galls. Downy mildew was only seen on the northern side of PNG. Leaf splitting disease, also caused by a Peronosclerospora species, was common in S. spontaneum around Popondetta. A number of minor uniquely PNG diseases was seen including veneer blotch and target spot. No sugarcane smut was
observed at any location; ratoon stunting disease was not detected either. In relation to insects, of note was the widespread distribution of stem borers and planthoppers. The two planthopper genera, Perkinsiella and Eumetopina, account for the transmission of some very important sugarcane viral diseases and their broad distribution in PNG is of great significance. Eumetopina has been observed in the Torres Strait and on the northern end of Cape York. Rhabdoscelus obscurus (sugarcane weevil borer) had limited distribution. Some Chilo larvae collected were unrecognised and may be new species. There seemed to be a low awareness of sugarcane quarantine in PNG; movement of hybrid cane to remote villages around the country has been occurring for
some time. This is of concern both for the spread of local and exotic pests and diseases and for the loss of S. officinarum germplasm. Actions are being planned in cooperation with PNG Government agencies to minimise the chance of sugarcane pest and disease spread.