Nuclear DNA based species delineations ofCoccusscale insects in symbiosis with plants and ants, and the role of plant epicuticular wax in structuring associations

Taxonomy of coccids (Hemiptera: Coccidae: Coccus L.) associated with Crematogaster ants (Hymenoptera: Formicidae) in the stems of Macaranga plants (Euphorbiaceae) in Southeast Asia

“…The first molecular phylogenetic studies of Macaranga coccids were based on mitochondrial data, specifically from cytochrome oxidase I (COI) (Ueda et al , 2010, but most of the recovered mitochondrial lineages contained more than one coccid morphospecies. As explained by Quek et al (2017), this latter pattern is consistent either with incomplete lineage sorting or hybridisation, or with the presence of ancient nuclear copies of mitochondrial DNA (NUMTs) that would lead to the COI phylogeny being based on both nuclear copies and actual mtDNA sequences and thus not reflecting the true cladogenetic history of the mtDNA. A recent analysis using the same coccid samples as Ueda et al (2008Ueda et al ( , 2010) but based on two nuclear genes, elongation factor 1 α (EF-1α) and wingless (WG), recovered clades that are congruent with morphologically defined groups of coccids.…”

“…Although associations of coccids with ants are beneficial for both partners, usually they are facultative, with the ants often existing without the coccids and vice versa (Gullan 1997). In the Macaranga-Crematogaster-coccid system, the coccids occur in the ant nest inside the hollow stems of almost all healthy Macaranga plants, but the specificity of the coccids for particular ant or plant species is not high, although some associations occur more frequently than expected in relation to partner availability Quek et al 2017). Furthermore, it is common to find two or three coccid species living inside a single Macaranga plant Houadria et al 2018).…”

“…In addition to the ants, myrmecophytic Macaranga species usually house honeydew-producing coccids (Hemiptera: Coccomorpha: Coccidae: Coccus L.) inside their hollow stems (Heckroth et al , 2001Ueda et al 2008;Quek et al 2017). The coccids provide the ants with sugar-rich liquid waste called honeydew, supplementing the food bodies produced by the plants (Heckroth et al 2001;Itino et al 2001a).…”

“…Seven species of Coccus have been described from specimens collected inside the hollow stems of Macaranga plants in close association with ants (Morrison 1921;Takahashi 1952;García Morales et al 2017). Based on nucleotide sequence data, the type species of Coccus, C. hesperidum L., has been shown to be closely related to the Macaranga coccids (Lin et al , 2017bQuek et al 2017;T. Kondo and L.G.…”

“…For this revision, we have examined all available microscope slide preparations of Macaranga coccids to assess the morphology of the adult females in light of the recently available nrDNA data used to produce figure 3 of Quek et al (2017). We define species as genetically distinct clusters within which individuals share two or more diagnostic morphological traits.…”