Mirax ceduna Slater-Baker, 2025

Slater-Baker, Mollie-Rosae, Guzik, Michelle, Rodriguez, Juanita, Howe, Andy, Woodward, Alice, Ducker, Nathan & Fagan-Jeffries, Erinn, 2025, Three new species of Australian miracine parasitoid wasps collected by regional schools as part of the Insect Investigators citizen science project (Hymenoptera, Braconidae, Miracinae), Journal of Hymenoptera Research 98, pp. 19-45 : 19-45

Mirax ceduna Slater-Baker sp. nov.

Fig. 2

Specimens examined.

Holotype: Australia • 1 ♀; South Australia, Ceduna ; 32°08.22'S, 133°0.26'E; 15–22 Mar. 2022; Ceduna Area School students leg.; M / T; BOLD Sample ID: BIOUG 84494-A 06; BOLD Process ID: ASMII 1811-22; SAMA 32-49901

Diagnosis.

This species can be differentiated from M. cowellensis by the dimensions of the head in dorsal view, with dorsal head width / medial length being 2.1 in M. ceduna , compared to 1.7 in M. cowellensis . When viewed anteriorly, the head appears sub-triangular in shape, with the eyes more bulged in the dorsal half in M. ceduna , whist the anterior head appears ovoid in M. cowellensis . M. ceduna may be separated from M. trianguliceps by the following characters: scape, pedicel and basal flagellomeres dark brown in M. ceduna , as opposed to yellow-brown in M. trianguliceps ; dorsal head and face densely setose throughout in M. ceduna , whilst dorsal head is sparsely setose, and medial region of the face lacks setae in M. trianguliceps ; inner eye margin narrowing slightly posteriorly (towards clypeus) in M. ceduna , whereas it is approximately parallel in M. trianguliceps . These species may be best separated based on DNA barcodes for which the holotype of M. ceduna is 8.6 % and 11.5 % divergent from holotypes of M. cowellensis and M. trianguliceps respectively (Fig. 1 ; See Suppl. material 2). M. ceduna can be distinguished from all other described Australian miracines ( M. arcisensis , M. caelicus , M. kaatijan , M. supremus ) by the absence of a propodeal medial longitudinal carina.

Description.

Size: body length 1.4 mm; fore wing length 1.4 mm; length of antenna slightly shorter than body length (Fig. 2 A ).

Colour: head and mesosoma dark brown, except for yellow mandibles with brown tip and dull yellow mouthparts; metasoma dull yellow basally, gradating to brown distally; T 1 yellow with brown margin; T 2 yellow; ovipositor sheaths brown; hind coxa, femur, tibia and tarsus yellow-brown; fore wing veins and pterostigma translucent yellow.

Head: dorsal head 2.1 × wider than medial length (Fig. 2 F ); dorsal head width 1.8 × face height (Fig. 2 E, F ); head and face smooth, densely setose throughout (Fig. 2 E, F ); head shape sub-triangular in anterior view (Fig. 2 E ); dorsal eye length (maximum length measured diagonally) 0.7 × distance between the eyes at narrowest point (Fig. 2 F ); dorsal medial head length 1.2 × longer than dorsal eye length; distance between the eyes at narrowest point 0.6 × head width in dorsal view (Fig. 2 F ); ratio POD: POL: OOL = 1: 2.8: 3.6 (Fig. 2 F ); inner eye margin narrowing slightly posteriorly (towards clypeus; Fig. 2 E ); eyes with a few short, sparse setae (barely visible); antennae with 14 segments; scape 1.6 × longer than wide; pedicel 1.7 × longer than wide; first flagellomere 3.5 × longer than wide; 11 th flagellomere 2.1 × longer than wide; apical flagellomere pointed; distal end of each flagellomere with several thickened setae which are longer than surrounding setae.

Mesosoma: mesosoma 0.4 × body length, 1.5 × longer than wide; anteromesoscutum mostly smooth, densely setose; scutellar sulcus faintly indicated by smooth, shallow depression (Fig. 2 D ); scutellum with small – medium, semi-elliptical medio-posterior depressions, separated by distance approximately equal to one depression (Fig. 2 D ); propodeum mostly smooth (Fig. 2 D ).

Wings: pterostigma 2.2 × longer than wide, with outer edge rounded and protruding slightly from wing outline (Fig. 2 C ); length of vein 2 RS 4.8 × r-rs, vein 2 - M 2.7 × longer than r-rs (Fig. 2 C ).

Legs: hind coxa, femur and tarsus densely setose, except for basal hind coxa sparsely setose; length of hind femur 2.1 × hind basitarsus; length of hind tibia 2.9 × hind basitarsus.

Metasoma: metasoma 0.5 × body length; T 1 approximately 2.1 × longer than maximum width, teardrop shaped, rounded apically; T 1 smooth, with a few setae distally; ovipositor sheaths short, 2.7 × longer than wide, densely setose (Fig. 2 G ).

Male. Unknown.

Remarks.

As of publication, this species forms BOLD BIN: BOLD: AES 9162 and is 7.69 % divergent from its nearest neighbour based on COI on BOLD. The holotype is deposited at the South Australian Museum, Australia.

Etymology.

This species was named in honour of the collection locality and Ceduna Area School students who collected the specimen. This species is colloquially known by the students as the ‘ golden-bum wasp’, however a collaborative decision was made to have the formal scientific name be more broadly relevant to the local community. The epithet ‘ ceduna’ is a noun in apposition.

Distribution.

This species is currently known from Ceduna, South Australia, however may be found in other parts of Australia. Further sampling is required to determine an accurate distribution for this species.

Figures

Figure 1. Maximum Likelihood COI tree of Miracinae, focusing on specimens collected in Australia. Ultrafast bootstrap support values are shown beside major nodes. Morphological character state of the propodeum, and a summary of species delimitation results are shown on the right. A full version of this tree is provided in Suppl. material 4.

Figure 2. Mirax ceduna holotype A lateral habitus B dorsal habitus C wings D dorsal view of scutellar medio-posterior depressions and propodeum E anterior head F dorsal head G lateral posterior metasoma showing ovipositor and sheaths.