Learn more: PMC Disclaimer | PMC Copyright Notice
Rediscovery and redescription of Centrodora damoni (Girault) (Hymenoptera: Aphelinidae) from Australia, an egg parasitoid of Gonipterus spp (Coleoptera: Curculionidae), after nearly a century
‡Associated Data
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.
Materials and methods
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. Fig.1,1, Table Table11.
Table 1.
Collection sites at which Centrodora damoni was discovered.
| Collection site | Latitude | Longitude | Collection date | Egg Capsules collected | Nr. of emergences | Host | Host plant |
| Tunbridge | 42°07.076 | 147°19.600 | 15/21 Nov 2012 | 1430 | 6 | Gonipterus spp. | Eucalyptus ovata |
| New Norfolk | 42°47.272 | 147°03.743 | 17/23 Nov 2012 | 90 | 6 | Gonipterus spp. | Eucalyptus globulus |
| Grindelwald1 | 41°21.446 | 147°00.966 | 19 Nov. 2012 | 100 | 14 | Gonipterus spp. | Eucalyptus globulus |
| Hamilton1 | 42°37.846 | 146°54.760 | 23 Nov. 2012 | Gonipterus spp. | Eucalyptus ovata | ||
| Hayes1 | 42°45.432 | 147°00.028 | 23 Nov. 2012 | Gonipterus spp. | Eucalyptus globulus |
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 illumination. Images were processed using the stacking software Automontage (Synoptics, Cambridge, UK), and further edited with Adobe Photoshop CC 2014.
Terminology
Morphological terminology and the format for species descriptions follow Polaszek 1991.
Depositories & Abbreviations
The following institutions provided specimens and/or are depositories for material examined:
BMNH: Natural History Museum, London, UK.
QM: Queensland Museum, Australia.
RAIZ: Instituto de Investigação da Floresta e Papel, Eixo-Aveiro, Portugal.
Taxon treatments
Centrodora damoni
(Girault, 1922)
- Aphelinus damoni Girault 1922: 208.
- Centrodora damoni (Girault) Hayat and Fatima 1990: 250; Dahms 1983: 209.
Materials
- Type status: Lectotype. Occurrence: occurrenceDetails: [AUSTRALIA: Queensland, Wynnum March 1st 1922] Aphelinus damoni Gir. ♀; 3771.; occurrenceRemarks: On a slide with "Coccidoxenus syrphi" (QM). Slide 1 of Dahms (1983).; recordedBy: Girault A.A.; individualCount: 1; sex: female; lifeStage: adult
- Type status: Paralectotype. Occurrence: occurrenceDetails: [AUSTRALIA: Queensland, Wynnum March 1st 1922] Aphelinus damoni Gir. ♀ (QM).; occurrenceRemarks: Slide 4 of Dahms (1983).; recordedBy: Girault A.A.; individualCount: 1; sex: female; lifeStage: adult
- Type status: Other material. Occurrence: occurrenceDetails: [AUSTRALIA:] FCT Canberra; ova Gonipterus: Aphelinus damoni Girault [8 ♀♀] (QM).; occurrenceRemarks: Slide 2 of Dahms (1983).; recordedBy: Girault A.A.; individualCount: 8; sex: female; lifeStage: adult
- Type status: Other material. Occurrence: occurrenceDetails: [AUSTRALIA:] FCT Canberra; ova Gonipterus: Aphelinus damoni Girault [5♀3♂] (QM).; occurrenceRemarks: Slide 3 of Dahms (1983).; recordedBy: Girault A.A.; individualCount: 8; sex: 5 female, 3 male; lifeStage: adult
- Type status: Other material. Occurrence: occurrenceDetails: 2♀ AUSTRALIA: Tasmania, Nunamara on Gonipterus sp.; C. Valente; DNA1020, 1021 (BMNH/QM); 2♂ AUSTRALIA: Tasmania, multiple sites on Gonipterus sp.; 2012/13; C. Valente; A2, A5 (BMNH/QM).; recordedBy: Valente C.; individualCount: 4; sex: 2 female, 2 male; lifeStage: adult
Description
(Figs (Figs2,2, ,3,3, ,4,4, ,5,5, ,6,6, ,7,7, ,8,8, ,9,9, ,10,10, ,11,11, ,1212)
Female. Body length: 1.00 mm (Fig. (Fig.9:9: Lectotype - length approximate as specimen is dissected and crushed).
Colour. Fig. Fig.2.2. Ground colour cream/off-white. Two broad longitudinal stripes on mesoscutum, extending to scutellum, propodeum laterally, and most of gaster, golden brown. Darker pigmentation on ocelli, notauli, hind tibia and tarsus. Wings hyaline.
Morphology
Head. Frons and antennal scrobes with very fine reticulate sculpture, frons below ocellar triangle with dense robust setae. Maxillary palp two-segmented. Antenna (Figs (Figs3,3, ,4)4) with radicle 2.1× as long as wide. Scape 4.0× as long as wide, 3.3× as long as radicle, and 2.2× as long as pedicel, flagellum with four flagellomeres; F1 and F2 combined length longer than F3, F3 1.3× as wide as long, much shorter than pedicel plus F1 and F2, and 0.3× as long as clava; clava with 8-9 multiporous plate sensilla (mps – Fig. Fig.4).4). Clava with an obliquely truncate apex with numerous basiconic peg sensilla (Fig. (Fig.4).4). Clava 2.1× as long as wide; mps 0.3× length of clava.
Mesosoma. Lateral lobe of mesoscutum with two setae (Fig. (Fig.5).5). Mid lobe of mesoscutum with approximately 13 pairs of setae (Fig. (Fig.5)5) and reticulate sculpture. Scutellum with two pairs of setae (Fig. (Fig.5).5). Fore tibial calcar 0.8× length of basitarsus. Fore wing (Fig. (Fig.6)6) uniformly hyaline, 2.3× as long as broad; longest seta of posterior marginal fringe 0.1× width of wing; marginal vein with row of six long setae along anterior margin; discal setation relatively uniform. Submarginal vein with row of four long setae along anterior margin. Hind wing 3.8× as long as broad, posterior marginal fringe 0.3× width of wing; discal setation relatively uniform.
Metasoma. Ovipositor (Fig. (Fig.5)5) 7.7× as long as hind basitarsus. Third valvula approximately 0.2x total ovipositor length.
Male. Body length generally 0.8x that of female. Colour and morphology similar to female. Antenna (Fig. (Fig.7)7) with scape shorter and broader than in female (cf Figs Figs3,3, ,7).7). Genitalia as in Fig. Fig.88.
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.
Distribution
Australia: ACT, Queensland, Tasmania (probably widespread).
Acknowledgements
We are grateful to Chris Burwell, Senior Curator of insects at Queensland Museum, for the loan of the Girault slides. John Noyes’ Universal Chalcidoidea Database was indispensable in preparing this paper. Altri Florestal SA (Portugal) contributed to financial support of insect collection. The paper benefited considerably from reviews by Dr M. Hayat, Dr S. Manzari and an anonymous reviewer.
References
- Dahms E. C. A checklist of the types of Australian Hymenoptera described by Alexandre Aresene Girault: II. Preamble and Chalcidoidea species A-E with advisory notes. Memoirs of the Queensland Museum. 1983;21:1–255. [Google Scholar]
- Girault A. A. New chalcid flies from Australia. The Entomologist. 1922;55:205–208. [Google Scholar]
- Hayat M. Aphelinidae of India (Hymenoptera: Chalcidoidea): a taxonomic revision. Memoirs on Entomology, International. 1998;13:1–416. [Google Scholar]
- Hayat M. Additions to the Aphelinidae of India (Hymenoptera: Chalcidoidea) - 2, Genus Centrodora Foerster. Oriental Insects. 2010;44:49–68. doi: 10.1080/00305316.2010.10417606. [CrossRef] [Google Scholar]
- Hayat M., Fatima K. Taxonomic studies on Aphelinus (Hymenoptera: Aphelinidae) 1. The Australian species described by A.A. Girault. Oriental Insects. 1990;24:247–252. [Google Scholar]
- Mapondera T. S., Burgess T., Matsuki M., Oberprieler R. G. Identification and molecular phylogenetics of the cryptic species of the Gonipterus scutellatus complex (Coleoptera: Curculionidae: Gonipterini). Australian Journal of Entomology. 2012;51:175–188. doi: 10.1111/j.1440-6055.2011.00853.x. [CrossRef] [Google Scholar]
- Noyes JS. Collecting and preserving chalcid wasps (Hymenoptera: Chalcidoidea). Journal of Natural History. 1982;16:315–334. doi: 10.1080/00222938200770261. [CrossRef] [Google Scholar]
- Noyes JS. Universal Chalcidoidea Database. World Wide Web electronic publication. http://www.nhm.ac.uk/chalcidoids. [2015-12-31T00:00:00+02:00];
- Polaszek A. Egg parasitism in Aphelinidae (Hymenoptera: Chalcidoidea) with special reference to Centrodora and Encarsia species. Bulletin of Entomological Research. 1991;81:97–106. doi: 10.1017/s0007485300053293. [CrossRef] [Google Scholar]
- Polaszek A., Ayshford T., Yahya BE., Fusu L. Wallaceaphytis: an unusual new genus of parasitoid wasp (Hymenoptera: Aphelinidae) from Borneo. Journal of Natural History. 2013;Wallace 100 centenary:17–29. [Google Scholar]