Rediscovery and redescription of Centrodora damoni (Girault) (Hymenoptera: Aphelinidae) from Australia, an egg parasitoid of Gonipterus spp (Coleoptera: Curculionidae), after nearly a century

Abstract Background Centrodora is a relatively common and widespread genus of morphologically diverse species, and is the most polyphagous genus known within the Aphelinidae, attacking eggs of insects in addition to pupae of Diptera and Hymenoptera, and nymphs of Hemiptera (Polaszek 1991). There are currently about 60 valid species in the genus, but given its morphological and biological diversity, some elevation of species-groups and subgenera to genus-level might be useful in future. Centrodora is represented in Australia by twelve species (Noyes 2015). New information Centrodora damoni (Girault) is redescribed and diagnosed from recently collected specimens reared from the eucalyptus weevil Gonipterus sp. near scutellatus Gyllenhal (Coleoptera: Curculionidae) from Tasmania, Australia. A lectotype is designated from a syntype specimen.


Introduction
Centrodora Foerster is a relatively common and widespread genus of morphologically diverse species, and is the most polyphagous genus known within the Aphelinidae, attacking eggs of insects in addition to pupae of Diptera and Hymenoptera, and nymphs of Hemiptera (Polaszek 1991). There are currently about 60 valid species in the genus, but given its morphological and biological diversity, some elevation of species-groups and subgenera to genus-level might be useful in future. Centrodora is represented in Australia by twelve species (Noyes 2015). The genus appears to be of moderate importance as a naturally-occurring primary parasitoid of plant-feeding insects, including some pests (Polaszek 1991). The genus has been split into two species-groups based on the Indian species: the amoena-group and idioceri-group (Hayat 1998, Hayat 2010). Although C. damoni is currently known only from Australia, it fits better within the idioceri-group. Centrodora damoni was described by A.A. Girault in 1922 from Queensland as Aphelinus damoni, and later transferred correctly to Centrodora by Hayat and Fatima 1990. The two syntype females were collected in a forest, and not reared, but later Girault correctly identified a long series, including the first recorded males, from "ova Gonipterus" from Canberra.
The host of both the recent and historical material can, unfortunately, only be identified currently as Gonipterus sp. Mapondera et al. 2012 have shown that what was known for a long time as a single species Gonipterus scutellatus Gyllenhal, commonly known as the eucalyptus snout, beetle eucalyptus weevil or the gum tree weevil, is in fact a complex of at least 10 distinct species, at least 5 of which occur in Tasmania.

Collection
In 2012, field sampling was undertaken on 11 sampling sites in Tasmania, Australia, by the second author (CV). At two of the collection localities, Tunbridge and New Norfolk, Centrodora damoni was discovered in egg capsules of Gonipterus spp. on Eucalyptus ovata and E. globulus. At a further three sites (Grindewald, Hamilton and Hayes) the parasitoid emerged from an assortment of egg capsules, see Fig. 1 Because few egg capsules were collected at these locations, they were placed on the same container.
Specimens were reared from freshly laid Gonipterus sp. egg capsules, emerging 54-56 days after parasitism, at 15˚C. The Centrodora parasitoids were preserved in 70% ethanol before identification by the fourth author (AP).

Identification
Specimens preserved in ethanol were extracted for genomic DNA using a "non-destructive" extraction technique (Polaszek et al. 2013). Several PCRs for the 28S D2 and D2-D3 ribosomal DNA fragments using a range of tried and tested primers were unsuccessful. The method of preservation -70% ethanol, possibly with some methanol present -might have led to degradation of DNA. Attempts will be made in the near future to collect fresh material for DNA sequencing.
Following DNA extraction, specimens were dissected and slide-mounted in Canada balsam following the standard protocol described by Noyes 1982. Photographs were made using a Leitz Ortholux compound microscope with Nomarski Differential Interference Contrast  Table 1.
Collection sites at which Centrodora damoni was discovered.

Terminology
Morphological terminology and the format for species descriptions follow Polaszek 1991.
Male. Body length generally 0.8x that of female. Colour and morphology similar to female. Antenna (Fig. 7) with scape shorter and broader than in female (cf Figs 3, 7). Genitalia as in Fig. 8 . Centrodora damoni, other Girault material Host. Gonipterus sp. (Coleoptera: Curculionidae). Based on the type locality of C. damoni (Queensland), the host species is likely to be one of the new species mentioned in Mapondera et al. 2012.

Diagnosis
Centrodora damoni can be distinguished from the other 11 Australian species in the genus by the following combination of characters: Two broad longitudinal stripes on mesoscutum, extending to scutellum; ovipositor less than half total body length (excluding head); apex of antennal clava broadly rounded; fore wing with linea calva present.