Native and Exotic Pests of Eucalyptus: A Worldwide Perspective

Abstract

Eucalyptus species, native to Australia, Indonesia, the Philippines, and New Guinea, are the most widely planted hardwood timber species in the world. The trees, moved around the globe as seeds, escaped the diverse community of herbivores found in their native range. However, a number of herbivore species from the native range of eucalypts have invaded many Eucalyptus-growing regions in North America, Europe, Africa, Asia, and South America in the last 30 years. In addition, there have been shifts of native species, particularly in Africa, Asia, and South America, onto Eucalyptus. There are risks that these species as well as generalist herbivores from other parts of the world will invade Australia and threaten the trees in their native range. The risk to Eucalyptus plantations in Australia is further compounded by planting commercially important species outside their endemic range and shifting of local herbivore populations onto new host trees. Understanding the mechanisms underlying host specificity of Australian insects can provide insight into patterns of host range expansion of both native and exotic insects.

Establishment of Psyllaephagus parvus and P. perplexans as serendipitous biological control agents of Eucalyptus psyllids in southern California

“…In spite of continuous monitoring for adult parasitoids on sticky traps from 2004 onward, we did not detect parasitoids until 2007. There have been at least 16 invasive insect pests of eucalyptus introduced into California (Paine et al 2011), all in the absence of natural enemies. All of the invasive psyllids have become established first in California and have been subsequently discovered in other eucalypt growing regions of the world (Paine et al 2010).…”

“…Until 1984, eucalypts were free of both insect and disease pests. Since that time, however, a series of herbivorous insect species across at least four feeding guilds have invaded California and are now causing significant damage to many of the eucalypt species in the state (Gill 1998;Paine et al 2011). Since eucalypts are planted widely in California and many trees are quite large, biological control programs offer the only economically and logistically feasible mechanism for controlling many of the invasive eucalyptus herbivores.…”

Endophytic Cryphonectriaceae on native Myrtales: Possible origin of Chrysoporthe canker on plantation-grown Eucalyptus

“…The nursery/plant trade has been, and continues to, actively move seeds, seedlings and plants of the Myrtales internationally (Ferreira et al 2008;Old et al 2003;Paine et al 2011). Species of Chrysoporthe have already been shown to be capable of host shifts between native and non-native Myrtales (Heath et al 2006;Van der Merwe et al 2010 and it is likely that there are many more examples of this situation.…”

First record of the eucalypt gall-wasp Leptocybe invasa (Hymenoptera: Eulophidae) from Uruguay

“…have been extensively used as shade and shelter forest in cattle breeding. Paine et al (2011) suggest a correlation between the increase of global area planted with Eucalyptus spp. and the arrival of new insects and diseases.…”

“…The last wave of world invasive forest pests has been characterized by small, cryptic insects, notably gall forming species (Paine et al 2011). The Eucalyptus gallwasps Ophelimus maskelli Ashmead 1900, Selitrichodes globulus La Salle and Gates 2009 and Leptocybe invasa Fischer and La Salle 2004 are well known because of their economic importance, though the latter is particularly relevant due to the aggressiveness of the attack and its rapid dispersion (Paine et al 2011).…”