Insect damage in Eucalyptus: A review of plantations in Chile

Chile has more than 330 000 ha of eucalypt plantations, predominantly in th e eighth to the tenth region (approximately 34 to 41 degreesS). Eucalyptus globulus ssp. globulus is the principal eucalypt planted, but Eucalyptus ni tens, Eucalyptus camaldulensis, Eucalyptus delegatensis and Eucalyptus vimi nalis are also grown. There are four main insect pests that have been detec ted attacking these eucalypts in Chile: the defoliator Gonipterus scutellat us, the bark borers Phoracantha semipunctata and Phoracantha recurva and th e native wood borer Chilecomadia valdiviana. More recently, Thyrinteina arn obia and Ctenarytaina eucalypti have been detected. Gonipterus scutellatus and P. recurva have been discovered in Chile within the last 2 years and it is hoped they may still be eliminated using a combination of biological co ntrol and chemical control of local populations. Phoracantha recurva and P. semipunctata are not considered a problem because attack only occurs in ar eas of water deficit, away from current eucalypt plantations. Chilecomadia valdiviana can damage plantations of E. nitens but rarely attacks other euc alypts. Chilecomadia valdiviana may cause future problems through further h ost shifts. Thyrinteina arnobia has only been detected during quarantine su rveillance in the port of Valparaiso. Ctenarytaina eucalypti, recently dete cted in August 1999, had an initial limited distribution in the first regio n. However, since then, this insect has expanded its distribution south up to the tenth region. None of the insects recorded on eucalypts in Chile to date currently presents a threat to the eucalypt industry. It is also essen tial that additional resources are made available for their continued monit oring and control, particularly given that the 44% of plantations are held by small to medium property owners that would otherwise be unable to contro l a serious outbreak because of economic restrictions.