January 2006. Some bad news from American Samoa. The Erythrina gall wasp has been detected and appears to already be widespread on the main island of Tutuila. It is damaging both Erythrina variegata and E subumbrans in most villages on the south shore and a couple on the north side of the island. Checks are beng made to see if the insect is present in the Manu’a Islands. Information on the wasp is available at:
It has also been reported from Guam and also from Thailand. In the latter, it has been causing heavy damage on shoots and young twigs of Erythrina variegata trees since early 2004 at Khao She-Chan Buddhist Memorial Park, about 10 km further east from Pattaya near Nong Nooch Garden on the highway to Sattahip and Rayong, on the Eastern coastline of the Gulf of Thailand. The damage was much higher in June 2004 than in March 2005 when the samples were collected and the wasp specimens kept at NBCRC, Kasetsart University. (A gall wasp in Eucalyptus reported by a member from Thailand is likely to be another eulophid, not Quadrastichus erythrinae.
The State of Hawaii Department of Agriculture New Pest Advisory No. 05-03 May 27, 2005 updated November 14, 2005 (see above) reported its occurrence in Guangdong, southern mainland China and Taiwan.
Dr Mohsen M Ramadan, exploratory entomologist of HDOA, is now in South Africa and Tanzania exploring for its natural enemies. The wasp was described by Kim et al. in 2004 from specimens from Reunion, Mauritius and Singapore.
The damage on Malay apple (Syzygium) is caused by a psyllid, Trioza vitiensis Kirkaldy (previously Megatrioza), and has been in the Pacific Islands and elsewhere for a long time (lower photos). It should not be confused with the damage caused by the Erythrina gall wasp, Quadrastichus erythrinae.