First report of the eucalyptus leaf beetle Paropsisterna selmani in the United Kingdom and in Ireland
The NPPO of the United Kingdom recently informed the EPPO Secretariat of the first record of Paropsisterna selmani (Coleoptera: Chrysomelidae) on its territory. An infestation was found on several species of Eucalyptus in a botanical garden in Surrey (Southeastern England). The identity of the pest was confirmed by morphological means at Fera. Several eucalyptus plants were infested but the full extent of the infestation remains to be determined. The source of this introduction is unknown and is currently being investigated. No statutory action is being taken against P. selmani. However, the botanical garden will be surveyed by staff members of the garden to determine the extent of the infestation. Although one unconfirmed photo of the beetle was taken in a garden in London in 2012, this is the first confirmed report of P. selmani in the United Kingdom.
The pest status of Paropsisterna selmani in the United Kingdom is officially declared as: Present, localised.
Paropsisterna selmani has recently been described as a new species (Reid and de Little, 2013). This species, originating from Australia, was first described on the basis of specimens collected from Tasmania (AU) and Ireland on Eucalyptus nitens. In 2007, the pest was found attacking cultivated Eucalyptus species in county Kerry, Ireland, but at that time it was tentatively identified as Chrysophtharta gloriosa (note: the genus Chrysophtharta has now been included into the genus Paropsisterna). P. selmani is widespread in eastern and central parts of Tasmania where it has been collected from native Tasmanian eucalyptus species (E. brookeriana, E. dalrympleana, E. rubida and E. gunnii), as well as on the exotic species E. nitens used in plantations. In Ireland, P. selmani has been collected on many eucalyptus species (E. glaucescens, E. globulus, E. gunnii, E. johnstonii, E. moorei, E. nicholii, E. nitens, E. parvula, E. pauciflora, E. perriniana, E. pulverulenta, E. vernicosa, and E. viminalis).
In Tasmania, adult beetles emerge from hibernation in spring, feed on foliage, and mate. Oviposition continues through summer to early autumn. Eggs are pale yellow and laid in groups of 5-15 on the leaf blade. Larvae feed on foliage and when fully developed, they drop to the ground where pupation occurs in the soil under host trees. Teneral adults emerge in autumn and feed prior to overwintering. In Ireland, field observations have shown that after the overwintering period, adults appeared on the foliage in April, and that adults that had emerged during the growing season were still active on the foliage in early November. The first egg masses and larvae were observed in early May. Teneral adults emerged in late June and again in late July/early August.
P. selmani is a pest in eucalyptus plantations in both Tasmania and Ireland where it can cause significant leaf defoliation. Both adult and larvae feed on the new foliage. Feeding activity results in characteristic notching in the leaves and disbudded shoot tips. Chronic defoliation and consumption of buds can have a long-term effect on tree growth. Leaf consumption on eucalyptus species grown for the production of ornamental cut-foliage has significant economic impact, as the end product is unmarketable. P. selmani is slowly spreading in Ireland (found in counties Kerry and Cork). Finally, it can be recalled that another eucalyptus leaf beetle, Paropsisterna bimaculata (= Chrysophtharta bimaculata – Tasmanian eucalyptus leaf beetle – formerly EPPO Alert List) had been intercepted several times by the United Kingdom on tree ferns (Dicksonia antarctica) imported from Australia. These plants are not hosts of P. bimaculata but could transport the pest (hitchhiking) over long distances. Although, the origin of the introduction of P. selmani into Europe is not known, imports of plants for planting or parts of plants from Australia most probably act as a pathway for this type of eucalyptus defoliators. P. selmani can now be added to an already rather long list of exotic eucalyptus pests which have been introduced into the EPPO region during the last decades (e.g. Blastopsylla occidentalis, Ctenarytaina eucalypti, Glycaspis brimblecombei, Ophelimus maskelli, Thaumastocoris peregrinus, Phoracantha recurva).
Fanning PD, Baars JR (2014) Biology of the Eucalyptus leaf beetle Paropsisterna selmani (Chrysomelidae: Paropsini): a new pest of Eucalyptus species (Myrtaceae) in Ireland. Agricultural and Forest Entomology 16, 45–53.
NPPO of the United Kingdom (2015-07).
Reid CA, de Little DW (2013) A new species of Paropsisterna Motschulsky, 1860, a significant pest of plantation eucalypts in Tasmania and Ireland (Coleoptera: Chrysomelidae: Chrysomelinae). Zootaxa 3681(4), 395-404.