Ophelimus migdanorum Molina-Mercader sp. nov. (Hymenoptera: Eulophidae): Application of Integrative Taxonomy for Disentangling a Polyphenism Case in Eucalyptus globulus Labill Forest in Chile

Abstract

In 2003, a new gall-inducing wasp of the genus Ophelimus was detected in the Valparaíso Region (Chile), affecting tree plantations of Eucalyptus globulus Labill and Eucalyptus camaldulensis Dehnh. Since then Ophelimus has been frequently detected in different plantations in Chile, covering a widespread area. A preliminary collaborative study suggests that the micro-wasp detected should be classified as a new Ophelimus species. In this paper, using an integrative approach (including genetic, morphological, and behavioral data), we addressed the delimitation and description of this new species. This study involved the use of brood adult specimens, raised at the laboratory of MIPlagas Ltda., from infested twigs of E. globulus collected in several localities between of Valparaíso and Los Lagos Regions (Chile). Morphological structures were described according to current Eulophidae taxonomic keys, as well as additional traits, such as gall morphology and behavior. Genetic characterization was implemented using a phylogenetic approach, based on a 648 bp specific fragment of the mitochondrial Cytochrome Oxidase I gene (COI 5 region) obtained from collected specimens and available databases (Genbank, NCBI, and BOLDSystem). Specifically, distinctive patterns of variation were detected in traits like gall and antennae morphology, growth habit trends, and a notorious polyphenism in the setae from the sub marginal vein. Overall evidence suggests that this new entity should be considered a new species in Ophelimus, which is henceforth named Ophelimus migdanorum Molina-Mercader.

Invasive gall‐forming wasps that threaten non‐native plantation‐grownEucalyptus: diversity and invasion patterns

“…The predominant Eucalyptus species affected by O. migdanorum include Eucalyptus globulus and E. camaldulensis (Informativo Fitosanitario Forestal, 2006). In severe instances, gall formation by Ophelimus species may lead to the premature dropping of leaves (Informativo Fitosanitario Forestal, 2006; Molina‐Mercader et al ., 2019).…”

“…Invasive hymenopteran species associated with Eucalyptus were described within one (e.g. O. eucalypti sensu lato; E. burwelli , S. globulus ) to sixteen ( O. migdanorum ) years after their first detection (Schauff & Garrison, 2000; La Salle et al ., 2009; Borowiec et al ., 2012; Borowiec et al ., 2019; Molina‐Mercader et al ., 2019). Even the two that were described prior to detection as invasive species ( Q. nova and O. maskelli ) were challenged with various taxonomical difficulties (see above) (Flock, 1957; Huber et al ., 2006).…”

Ophelimus bipolaris sp. n. (Hymenoptera, Eulophidae), a New Invasive Eucalyptus Pest and Its Host Plants in China

“…Ophelimus mediterraneus is also a thelytokous species and induces galls on the upper surface of the leaves on Eucalyptus species from the Maidenaria section, such as Eucalyptus globulus Labill and Eucalyptus gunii J. D. Hook [9]. While O. migdanorum is a biparental species and induces galls on stems, petioles, laminae and leaf venations of E. globulus and Eucalyptus camaldulensis Dehnh [10]. Considering the economic importance of Ophelimus species to the production of Eucalyptus trees, in this study, we aim to investigate the identity of the Ophelimus species we just found in Guangzhou, China, using an integrative taxonomic approach combining biological, morphological and molecular information.…”

“…The genus Ophelimus is native to Australia and currently contains 53 described species [ 9 , 10 ]. Available biological data indicate that species of the genus develop in galls on various species of Eucalyptus and are considered gall inducers [ 11 , 12 ].…”

“…Fourteen host species have been recorded for O. maskelli , with Eucalyptus camaldulensis Dehnhardt and Eucalyptus tereticornis Smith being economically important and particularly suitable species [ 14 ]. Recently, two species, Ophelimus mediterraneus Borowiec & Burks and Ophelimus migdanorum Molina-Mercader were newly described from the Mediterranean Europe [ 9 ] and Chile [ 10 ], respectively. Ophelimus mediterraneus is also a thelytokous species and induces galls on the upper surface of the leaves on Eucalyptus species from the Maidenaria section, such as Eucalyptus globulus Labill and Eucalyptus gunii J. D. Hook [ 9 ].…”