Research Article |
Corresponding author: Erinn P. Fagan-Jeffries ( erinn.fagan-jeffries@adelaide.edu.au ) Academic editor: Gavin Broad
© 2018 Erinn P. Fagan-Jeffries, Steven J.B. Cooper, Andrew D. Austin.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Fagan-Jeffries EP, Cooper SJB, Austin AD (2018) Three new species of Dolichogenidea Viereck (Hymenoptera, Braconidae, Microgastrinae) from Australia with exceptionally long ovipositors. Journal of Hymenoptera Research 64: 177-190. https://doi.org/10.3897/jhr.64.25219
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The subfamily Microgastrinae contains an extraordinarily rich diversity of parasitoid wasps which parasitise larval lepidopterans. The Australian fauna has generally been poorly studied, particularly for the very speciose genera. One such genus is Dolichogenidea Vierek, which in Australia is known from only six described species. Here we describe three new species of Dolichogenidea from Australia, which are distinguished by possessing extremely long ovipositors compared with the typical form for the genus. These are D. finchi Fagan-Jeffries & Austin, sp. n., D. mediocaudata Fagan-Jeffries & Austin, sp. n., and D. xenomorph Fagan-Jeffries & Austin, sp. n. In describing these new species we also discuss relationships within the genus, and the diversity and biology of the Australian fauna.
Microgastrinae , Dolichogenidea , parasitoid, ovipositor
The subfamily Microgastrinae are agriculturally and environmentally important as endoparasitoid wasps of larval lepidopterans. There are currently over 2700 species described worldwide (
The Australasian members of Dolichogenidea were reviewed by
Terms for general morphology follow
Dolichogenidea
Viereck, 191 1: 173 (as a subgenus of Apanteles Foerster s.1.). Type species, by original designation, Apanteles (Dolichogenidea) banksi Viereck. Generic status by
Fore wing areolet (second submarginal cell) absent (i.e. vein r-m absent); hind wing vannal lobe convex to almost straight and uniformly fringed by setae; propodeum often with a complete areola, sometimes areola reduced with at least posterior diverging carinae present, rarely with these carinae completely absent; metasoma with T2 variable in shape, but usually rectangular or subrectangular; hypopygium membranous mid-ventrally and expandable (sometimes folded inwards and hidden by laterotergites in dead specimens); ovipositor protruding from posterior metasoma, usually as long as or longer than length of metatibia.
In resurrecting Dolichogenidea,
Dolichogenidea is highly speciose and there are large numbers of undescribed species in Australia.
The newly described species appear to be quite rare, although two are widespread (Fig.
Holotype ♀: AUSTRALIA, WA, Kariijini NP, Kariijini Dr, 22.5716°S, 118.3072°E; 19-25/iv/2003, C Lambkin & T Weir, malaise in open Eucalyptus grassland, 814 m (
Dolichogenidea finchi can be separated from D. mediocaudata by having a longer ovipositor, smoother T1, and more consistent pale orange colouration of the legs; and from D. xenomorph by absence of a strong sculpturing pattern on the propodeum (Fig.
(Female). Colour. Head and body dark; tergites dark, T3 sometimes orange on lateral thirds (Fig.
Head. Antennae slightly shorter than body length; body length (head to apex of metasoma): 3.4–4.4 mm; ocular–ocellar line/posterior ocellus diameter: 1.4–1.9; interocellar distance/posterior ocellus diameter: 1.3–2.3.
Mesosoma. Anteromesoscutum densely and evenly punctate; mesoscutellar disc mostly smooth and shining with sparse punctures mostly associated with setae, lateral faces of the mesoscutellum normally smooth and shining to lunules but sometimes with a distinct line of pits or with subtle area of sculpturing posterior to lunules; number of pits in scutoscutellar sulcus: varies from 12 to 22; maximum height of mesoscutellum lunules/maximum height of lateral face of mesoscutellum 0.7–0.8. Propodeum with sparse punctures associated with setae, areola only indicated by smoother area in centre of propodeum and short carinae diverging from centre posterior margin of propodeum.
Fore wing length 3.2–4 mm; length of veins r/2RS 1.5-2.2; length of veins 2RS/2M 1.0–1.7; length of veins 2M/(RS+M)b 0.5-0.8; pterostigma length/width 2.6–3.1.
Legs. Metatibia inner spur length/metabasitarsus length 0.2–0.4.
Metasoma. T1 length/width at posterior margin 1.2–1.8; T1 shape broad, rectangular, almost parallel-sided; T1 mostly smooth with sparse punctures associated with short setae on lateral sides of posterior half; T2 width at posterior margin/length 2.1–3.1; T2 sculpture smooth and shiny, few shallow punctures associated with setae; T2/T3 boundary indistinct and sinuate. T3 smooth and shiny, at least twice as long as T2; hypopygium large with lateral creases, ovipositor sheath length/metatibial length 2.9–3.9.
Male. Unknown.
It is possible that if more specimens become available and are amenable to DNA sequencing, D. finchi, as described here, will turn out to be a species complex of several closely related species. There is variation in several morphological characters such as subtle differences in the length and shape of the metanotum, the colour of T3, and length of the ovipositor in relation to the metatibia. However, with so few specimens and a lack of molecular data we feel it is more practical at this stage to treat them as one variable species. Further, the COI sequences of the two specimens, sequenced as part of a parallel study (
This species is named for the late grandfather of one of us (EFJ), Alexander Finch, who was a sheep pastoralist near the town of Wilcannia, the locality for one of the paratypes.
This species occurs widely across the continent (Fig.
Whilst the host for this species has not been recorded, two specimens were collected in association with Eucalyptus. As D. xenomorph is the parasitoid of a larva feeding on Eucalyptus, it is a strong possibility that D. finchi also parasitises a Eucalyptus-associated lepidopteran.
Holotype ♀: AUSTRALIA, NSW, 8 miles ESE of Nimmitable 3600ft, emerged 03/xii/1969, I.F.B. Common & J. Cusbert, L19. Larva tying leaves on fallen dead branch of Eucalyptus pauciflora (
This species can be separated from D. finchi and D. xenomorph by having a shorter ovipositor (Fig.
(Female). Colour. Head and body dark other than S1-3 which are distinctly paler than posterior sternites; antenna dark; coxae (pro-, meso-, metacoxa): dark, dark, dark; femora (pro-, meso-, metafemur): pale, dark, dark; tibiae (pro-, meso-, metatibia): pale, pale, pale anteriorly, posterior half distinctly darker; tegula and humeral complex pale; pterostigma dark; fore wing veins pale proximally transitioning to dark distally.
Head. Antennae slightly shorter than body length; body length (head to apex of metasoma): 3 mm; ocular–ocellar line/posterior ocellus diameter: 2.2; interocellar distance/posterior ocellus diameter: 1.9.
Mesosoma. Anteromesoscutum densely and evenly punctate, no punctures at posterior margin; mesoscutellar disc mostly smooth and shining with sparse punctures mostly associated with setae, lateral faces of the mesoscutellum smooth and shining but with a distinct line of pits posterior to lunules; number of pits in scutoscutellar sulcus: varies from 12–13; maximum height of mesoscutellum lunules/maximum height of lateral face of mesoscutellum 0.7. Propodeum with deep non-uniform punctures, posterior half with rugose sculpturing, areola only indicated by a central depression and short carinae diverging from centre posterior margin of propodeum.
Fore wing length 2.7 mm; length of veins r/2RS 1.3; length of veins 2RS/2M 1.8; length of veins 2M/(RS+M)b 0.6; pterostigma length/width 2.8.
Legs. Metatibia inner spur length/metabasitarsus length 0.4.
Metasoma. T1 length/width at posterior margin 1.6; T1 shape broad, rectangular, almost parallel-sided; T1 with rugose sculpturing and sparse punctures over most of length; T2 width at posterior margin/length 2.0; T2 sculpture smooth and shiny, few shallow punctures associated with setae; T2/T3 boundary indistinct and sinuate. T3 smooth and shiny, at least twice as long as T2; hypopygium large with lateral creases, ovipositor sheath length/metatibial length 1.8.
Unknown.
This species is named for the length of the ovipositor, which appears to be intermediate between most Dolichogenidea and the extremely long ovipositors of D. xenomorph and D. finchi.
This species is only known from the holotype collected near Nimmitable in south-eastern NSW.
This specimen was reared from a lepidopteran larva tying leaves together on a dead branch of Eucalyptus pauciflora.
Holotype ♀: AUSTRALIA, NSW, 2.7 km NE of Queanbeyan, emerged 28/x/1979, I.F.B. Common, ex Ocystola euanthes Meyr (
Diolichogenidea xenomorph can be separated from D. mediocaudata by having a longer ovipositor, smoother T1, and lighter, more consistent colouration of the femora and tibiae. The species is very similar to D. finchi, but can be separated by the stronger sculpturing pattern on the propodeum (Fig.
(Female). Colour. Head and body dark, including tergites and sternites; antenna dark; coxae (pro-, meso-, metacoxa): dark, dark, dark; femora (pro-, meso-, metafemur): orange, orange, dark to orange; tibiae (pro-, meso-, metatibia): orange, orange, orange; tegula and humeral complex orange; pterostigma dark; fore wing veins pale proximally transitioning to dark distally.
Head. Antennae slightly longer than body length; body length (head to apex of metasoma): 4 mm; ocular–ocellar line/posterior ocellus diameter: 1.8–2.1; interocellar distance/posterior ocellus diameter: 1.7–2.5.
Mesosoma. Anteromesoscutum densely and evenly punctate; mesoscutellar disc mostly smooth and shining with sparse punctures mostly associated with setae, lateral faces of mesoscutellum with anterior shallow sculpturing posterior to lunules (Fig.
Fore wing length 4.3–4.4 mm; length of veins r/2RS 1.3–1.9; length of veins 2RS/2M 1.1–1.2; length of veins 2M/(RS+M)b 0.8–1; pterostigma length/width 2.6–3.
Legs. Metatibia inner spur length/metabasitarsus length 0.3–0.4.
Metasoma. T1 length/width at posterior margin 1.1–1.4; T1 shape broad, rectangular, almost parallel-sided; T1 mostly smooth with sparse punctures associated with short setae on lateral sides of posterior half; T2 width at posterior margin/length 4; T2 sculpture smooth and shiny, few shallow punctures associated with setae; T2/T3 boundary indistinct and sinuate. T3 smooth and shiny, at least twice as long as T2; hypopygium large with lateral creases, ovipositor sheath length/metatibial length 3.7–4.2.
The specimen from WA is here assigned to this species, but excluded from the type series due to its disjunct distribution which is also outside the known range of the host species. However, other species of the host genus are known from WA, but we take a more conservative approach until further specimens and host data become available.
This species is named for the fictional creature from the movie franchise ‘Alien’, which reportedly was inspired by the lifecycle of parasitic wasps. The name of the fictional creature comes from the Greek ‘xeno’ (strange) and ‘morphe’ (form) which is also appropriate, considering the remarkably long ovipositor of this species compared to other members of the genus. The species name is a noun in apposition.
Recorded from NSW and south-western WA.
Reared from Antipterna euanthes (Meyrick, 1885) (Oecophoridae), a species in which the larvae fold over the tip of a Eucalyptus leaf and continue developing even after the leaf is shed from the tree (
We thank Gavin Broad for assistance and access to material and imaging equipment at the Natural History Museum, London, and Zoltán Vas for providing images of the D. biroi holotype in the Hungarian Natural History Museum. We thank Jim Whitfield and José Fernández-Triana for useful discussions on the presence of long ovipositors in the genus Dolichogenidea. This work was funded by an Australian Biological Resources Study (ABRS) PhD top-up grant (CT215-08) to EFJ. EFJ acknowledges the support of an Australian Government Research Training Program Scholarship. The authors declare no conflict of interest.