Laotris luzulae Godfray, 2023

Godfray, H. Charles J., 2023, Laotris luzulae (Hymenoptera, Braconidae, Alysiinae, Dacnusini), a new species from the southwest of England, Journal of Hymenoptera Research 95, pp. 73-83 : 73

Laotris luzulae Godfray sp. nov.

Type material.

Holotype: female (code: NK64), Hencliffe Woods, south Gloucestershire, Grid Reference, ST6371, emerged 13.v.2003, in NMS.

Paratypes: female (code: NK62, in NHMUK with digital catalogue number NHMUK010885191), emerged 27.iv.2002, and male (code: NK63, in NMS), emerged 7.v.2003, otherwise same data as holotype; two females (codes: NK195, NK196, deposited in NMS), Steps Bridge, South Devon, Grid Reference, SX801884, both collected 15.iv.2004 deposited in NMS.

NK62, NK63 & NK64 were reared by DJ Gibbs and NK195 & NK196 by M. Storey.

Description of female

(Fig. 1 ). Size: body length (excluding antennae), 2.3-2.5 mm; wing length 2.7-3.0 mm.

Colour. Head black except for labrum, mandibles and part of cheek immediately above insertion of mandibles which are brown. Antennal scape, pedicel and proximal part of first flagellar segment brown with rest of flagellum black; palps pale yellow. Mesosoma black except for small brown patches near base of wings. Legs including coxae light yellow-brown (in some specimens with base of hind coxa dark) with only fifth tarsal segment infuscated. Petiole black with rest of metasoma shading from dark brown anteriorly to black posteriorly.

Head. Antennae with 30 or 31 segments (3 specimens each), approximately equal in length to wing; first flagellar segment 3.4 times as long as maximally wide, 0.75 times as long as scape plus pedicel; second flagellar segment 2.8 times as long as maximally wide; distal flagellar segments approximately two times as long as maximally wide. Head 1.7 times as wide as long in dorsal view, with sparse forward-directed setae on occiput and temples; ocelli arranged in an equilateral triangle with OOL almost exactly twice POL; OOL 2.3 times posterior ocellar diameter, a small medial depression on frons dorsal to the antennal insertions. In lateral view, width of eye approximately equal to width of cheek with frons slightly protruding beyond eye; clypeus distinctly protruding. Face at narrowest point half width of head and width and height (measured from ventral labrum rim to antennal insertion) equal, slightly roughened with extensive but not dense setae which are ventrally directed along eye margin, medially directed above labrum, dorso-medially directed on lateral panels of face, and dorsally directed near mid-line. Clypeus 0.4 times as high as maximum width, its ventral margin with a narrow carina which is shallowly concave medially and forms distinct angles at ventral-lateral corners. The clypeus is largely bare or with sparse ventrally directed setae. Labrum ventrally with dense setae which are approximately equal in length to height of labrum. Maxillary palps six-segmented and reaching to a little before middle of mesopleuron, last segment 6 times as long as wide and 1.3 times length of penultimate segment. Labial palps four-segmented. Mandible more or less parallel-sided, 1.9 times as long as medially wide, with a long central tooth and subequal first and last teeth; a small fourth tooth appears as an outgrowth on anterior edge of central tooth (not posterior edge as in many Chorebus spp.).

Mesosoma. Mesosoma in lateral view 1.4-1.5 times as long as high. Pronotum dorsally with a medial pit; laterally largely hairless, smooth and shining above oblique suture, with some rugosity around its margins. The oblique suture is rugose with some setae below. Mesoscutum dorsally 1.1-1.2 times as broad as long, anteriorly roughened, its surface covered with backwardly directed setae except for posterior lateral margins. Notaulices well-developed as a series of connected pits that converge on, but do not quite meet, the postero-medial fovea. Fovea elongate, 6-7 times as long as wide. Prescutellar furrow 3 times as broad as long, with a medial longitudinal costa and indistinct sub-medial costae. Scutellum smooth with backwardly directed setae, especially at margins and posterior apex. Postscutellum with backwardly pointed setae and a median carina that bluntly protrudes in lateral view. Propodeum strongly sculptured with backwardly directed setae, most dense posteriorly. Mesopleuron bare and shining centrally; epicnemial (antero-dorsal) area with setae and rugosity, a small patch of setae at postero-ventral corner; pleural suture and episternal scrobe smooth. Precoxal suture strong and ribbed, extending from anterior margin about four-fifth of way to posterior margin. Area below precoxal suture with setae. Metapleuron with rugose sculpture similar to propodeum, covered with quite dense postero-ventrally directed setae.

Legs. Hind coxa dorsally somewhat rugose. Hind femur 4.5 times as long as maximum width. Hind tarsus approximately same length as hind tibia. Ratio of hind tarsal segment lengths (from base): 1:0.58:0.39:0.31:0.38.

Wings. Pterostigma elongate, approximately 7 times longer than broad, more or less parallel-sided beyond origin of radius (r) (at 1/5) until 4/5 when it tapers to metacarp (R1a). First segment of radius (r) slightly longer than width of pterostigma; radius distally (RS) somewhat sinuate reaching wing margin before wingtip; metacarp half length of pterostigma. Vein m-cu received into first submarginal cell (antefurcal condition). First subdiscal cell closed at postero-ventral corner by 2cu-a.

Metasoma. Metasoma 1.2-1.3 times length of mesosoma. First tergite (petiole) 1.4 times as long as its posterior width, initially widening from base but approximately parallel-sided in posterior two thirds. At base, two carinae run from margins diagonally to join before centre and continue as a short, indistinct, medial ridge. Surface of first tergite rugose with some indistinct longitudinal ridges, covered in sparse backward-directed setae except for central area which is largely bare. Lateral and posterior edges of first tergite are margined by a narrow carina. Second tergite with an area of longitudinal striae that extends only over its basal 1/3-1/4. Most of tergite covered with sparse setae, except for posterior central area and posterior margin. There are rows of setae at bases of posterior metasomal tergites. Ovipositor does not project beyond apical tergite in retracted position.

Description of male

(Fig. 2 ). Size: body length (excluding antennae), 2.3-2.7 mm; wing length 2.7-2.8 mm.

The single reared male specimen has 33 antennal segments while the three swept male specimens have 29, 30 & 31 segments. Otherwise, the male is very similar to the female with no obvious sexual dimorphism.

Molecular analysis.

Sequence data from the mitochondrial CO1 gene (the standard barcode locus) were obtained from three specimens each of the new species and L. striatula . Full barcode sequences (658bp) were obtained from five specimens and 513bp from one specimen of L. luzulae . The BOLD database contains no further European specimens of Laotris but ten specimens of a species of wasp collected in the Yukon (Canada) and assigned the Barcode Index Number (BIN) ADV6100 which showed a 4.2% genetic distance from L. luzulae . The new species was placed in BIN AEO8807 and showed a 6.6% genetic distance from L. striatula (placed in BIN AEO8806) (Fig. 3 ). The magnitude of the genetic divergence supports the hypothesis based on morphology that L. luzulae is distinct from L. striatula , and also from the undescribed North American species.

Figures

Figure 1. Laotris luzulae sp. nov. female a general habitus b dorsal view of head and mesosoma c ovipositor d basal part of forewing e face and mandibles f dorsal view of first and second metasomal tergites g lateral view of head and mesosoma.

Figure 2. Laotris luzulae sp. nov. male a dorsal view of head and mesosoma b general habitus c mandible d face e dorsal view first and second metasomal tergites f lateral view of head and mesosoma.

Figure 3. Neighbour-joining tree (CO 1 gene, Kimura 2 - parameter model) of Laotris species with an Exotela flavicoxa (placed by some authors in the genus Antrusa) sequence used as an outgroup. The height of the triangular wedges represents sample size and their horizontal width the genetic variation within the species.