New Communities on Eucalypts Grown Outside Australia

Abstract

The expansion of eucalypt forestry worldwide has been accompanied by accidental and deliberate introductions of Australian insects associated with eucalypts. Local insect species have also colonized introduced eucalypts in many regions. This situation provides a unique opportunity to observe the development of new insect communities across trophic levels. Here the history of Australian invaders and native colonizers on eucalypts outside Australia is reviewed from the perspective of herbivore guilds: leaf chewers, sap suckers, wood borers, gall formers, termites. Historical patterns of invasion are identified across these guilds. Very few species of Australian leaf chewers, wood borers or termites have become widespread but these guilds are proportionately high in native colonizers. In contrast, sap suckers have multiple invasive species globally with relatively fewer native colonizers. The gall former guild also has several invasive species but so far includes no native colonizers, perhaps due to their tendency to have highly specific host plant associations. Natural enemies of Australian invaders are also members of new eucalypt insect communities, partly through planned biological control programs, but the rate of accidental introductions at higher trophic levels is increasing steadily. At the same time, local natural enemies enter eucalypt communities either to form new associations with Australian invaders or to follow native colonizers into this new habitat. Australian sap suckers have attracted far more new associations than other guilds so far. Native leaf chewers have often been followed by their local natural enemies into eucalypt communities, particularly in Brazil. Generally there are fewer records relating to local natural enemies and their role in new eucalypt communities. The complexity of new eucalypt communities outside Australia is expected to increase in future.

Expansion of the geographic range of the eucalypt pest Paropsisterna cloelia (Stål) (Coleoptera: Chrysomelidae) through synonymy and invasion

“…With the exception of T. sloanei , which is now found adventitiously in four global regions, paropsine beetles do not appear to be highly invasive. Of the estimated 300 paropsine species on eucalypts (Reid 2006), only nine are recorded outside Australia, and all but T. sloanei have remained in the single region in which they were first recorded (Mansfield 2016). Two of these same species, however, are also invasive in WA eucalypt plantations (Grimbacher et al .…”

“…Here, we have integrated traditional taxonomic methods with molecular analyses to reveal conspecificity within a broadly distributed eucalypt pest. Eucalypt‐feeding paropsine beetles continue to establish as invasive species, with at least six new species‐country records in the last decade (Mansfield 2016, Sánchez et al . 2015, CAMR pers.…”

“…2011) and more recently, Europe ( Paropsisterna selmani Reid & de Little) (Horgan 2011) and eastern Asia ( Paropsis atomaria Olivier – CAMR unpubl.). Only T. sloanei has established in more than one global region, with accidental introductions into NZ, Europe, North America (Mansfield 2016; Sanchez et al . 2015) and China (Anonymous 2019), while Paropsisterna m‐fuscum (Boheman) is invasive both within Australia (Grimbacher et al .…”

Phoracantha recurva (Coleoptera: Cerambycidae): First Report in the Atlantic Rainforest of Minas Gerais, Brazil

“…Unfortunately, the increase of the planted area with Eucalyptus spp. and related species, and the international trade of its products, are increasing accidental introductions of exotic insects (Mansfield 2016;Almeida et al 2018).…”

“…Phoracantha semipunctata (Fabricius) (Coleoptera: Cerambycidae) and Phoracantha recurva Newman (Coleoptera: Cerambycidae) have been introduced accidentally into different regions of the world, where they colonize weakened trees or cut logs. These insects can survive inside the wood while it is being processed for various uses (Wang et al 1999;Mansfield 2016). Larvae of these insects damage the trunk of host trees or their logs by forming galleries beneath their bark, with higher survival on trees that have been subjected to water stress (Hanks et al 1991).…”