Data-rich description of a new genus of praying mantid egg parasitoids, Lasallegrion gen. n. (Hymenoptera: Torymidae: Podagrionini), with a re-examination of Podagrion species of Australia and New Caledonia
Janšta, Petr
Delvare, Gérard
Baur, Hannes
Wipfler, Benjamin
Peters, Ralph S.
Journal of Natural History
2020
2020-09-23
54
9
755
790
Jansta, Delvare, Peters
Jansta, Delvare, Peters
2020
[255,702,1460,1486]
Insecta
Torymidae
Lasallegrion
Animalia
Hymenoptera
9
763
Arthropoda
genus
gen. nov.
( Figs 5–6, 7a–c, 8–13)
Typespecies Podagrion koebelei Crawford, 1912: 4–5, Figure 2; Bouček (1988): 141, Fig. 201
Etymology.The genus is named in honour of our late colleague John La Salle. The first part of the generic name refers to his family name, the latter (‘grion’) is the Latin word for crest (of teeth on the hind femora) and refers to the genus PodagrionSpinola, 1811that most closely resembles the new genus.
Diagnosis (females and homeomorph males only). Lasallegrion( Figure 6a) is readily distinguished from the other Podagrioninigenera based on the following characters: Antenna filiform with antennal formula 11173; single anellus transverse; clava not enlarged and distinctly 3-segmented, with segments completely encircled by fine sutures, clava of female with only narrow strip of micropilosity on 2 ndand 3 rdsegment ventrally ( Figure 6b); pronotum with a sharp carina delimiting collar anteriorly; neck short, with posterior part forming almost a right angle ( Figure 6c); propodeum with a median carina originating anteriorly, and dividing into two transverse branches at an obtuse inner angle approximately in the middle of propodeum, two lateral carinae originating from spiracular sulci and joining transverse branches posteriorly at about 2/3 of the propodeum length, the area bordered by transverse branches and by posterior 1/3 of lateral carinae originating from propodeal spiracle (adpetiolar area) with irregular rugulose carinae, the rest of propodeum dorsum reticulate to rugulose reticulate ( Figure 6d); metepimeron slender, anteriorly pointed, entirely reticulate and setose, without a polished median area, ventral margin carinate ( Figure 6c); metacoxal foramen largely surrounded by translucent integument anteriorly and medially; metadiscrimen as median stripe narrowing posteriorly, with transverse crests and delimited by irregular, sometimes broken, submedian ridges ( Figure 7a–c). Petiolar foramen of propodeum large in connection with the large and upturned condyle of the petiolus. Body of petiolus with a fine medioventral carina ( Figure 6f).
Description.Head. Head broader than high. Face, vertex, and temples shallowly reticulate with fine, short, and pale setae, about as long as 3–4 meshes of the reticulation, setation denser and longer on lower face than rest of head. Antennal scrobes without setae, more shallowly and more finely reticulate than rest of face, interantennal projection greatly protruding. Anterior margin of clypeus slightly convex to broadly toothed, slightly recessed relative to corners of oral fossa. Malar sulcus weakly present. Occipital carina completely encircling the back of the head, joining the hypostomal carina above the base of mandible ( Figure 6e). Toruli inserted high on head, their lower margins above median level of eye. Scape short and thick, reaching anterior margin of median ocellus. Flagellum with a single strongly transverse anellus, seven funicular segments and distinctly three–segmented clava with only narrow strip of micropilosity on 2nd and 3rd segment ventrally (micropilosity only present in females). Figure 5. Volume renders of the µ-CT scans of Lasallegrion gen. n.;( a), L. virescens, lateral; ( b), L. koebelei, lateral. Midsagittal sections showing the inner anatomy. Scale bars: 0.5 mm. Figure 6. Diagnostic characters of Lasallegrion gen. n.; L. koebelei(a – e), L. washingtoni(f). ( a), habitus, lateral; ( b), antenna, lateral; ( c), head and mesosoma, lateral (arrows indicate pronotal collar carina and metapleuron); ( d), propodeum, dorsal; ( e), head, posterior; ( f), petiolus and first sternite, ventral. Mesosoma. Pronotum and mesoscutal midlobe slightly flattened dorsally ( Figure 6c), and alveolate to areolate, lateral lobes of pronotum scabriculous to areolate. Pronotum and mesoscutum covered with fine, pale setae. Pronotal collar carinately delimited anteriorly on most of its width. Notauli complete, moderately converging, widely separated at transscutal line, shallowly impressed, and of contrasting colour, weakly obliterated by sculpture. Mesoscutellum with frenal line absent, frenal area well indicated by smoothly alutaceous sculpture without setae ( Figures 8d, 11e, 12e). Axilla less reticulate than rest of mesoscutum, especially lateral parts rather smooth with imbricate sculpture, sparsely covered with setae. Propodeum alveolate to areolate and without setae, sides of propodeum laterally to lateral carina steep and with no spiracular sulcus ( Figures 6d, 8d, 11d–e, 12d–e). Posterior ventral margin of the mesepimeron not reaching the metapleural venter. Metepisternum ( Figure 7a–e) with propodeal foramen placed posteriorly, not touching imaginary line drawn across the posterior margin of metacoxal foramina, distance between anterior margin of propodeal foramen and imaginary line between posterior margin of metacoxal foramina slightly less than diameter of propodeal foramen; outer ventral edge of propodeal foramen connected with outer posterior egde of metacoxal foramen by a distinct single carina; metacoxal foramen largely surrounded by translucent integument anteriorly and medially. Metacoxa long, almost as long as metafemur, areolate to punctate laterally, without setae, dorsally and ventrally setose with imbricate sculpture. Metafemur ( Figures 8e, 9e, 11c, 12f) enlarged, bearing strong teeth, imbricate and covered with pale setae. Metatibia greatly curved with a carinate crest ventrally, metatibial apex diagonally truncated and ventrally slightly produced, truncation length subequal to the width of tibia, with a single setose metatibial spur at apex of truncation. Fore wing with basal cell and speculum bare, basal vein and cubital vein indicated by a row of dense brown setae ( Figures 8f, 11f). Figure 7. Metepisternum, posteroventral, females. ( a), Lasallegrion koebelei; ( b), L. virescens; ( c), L. washingtoni; ( d), Podagrion idomenesp. gr.; ( e), P. pachymerum; ( f), Mantiphaga gongylusae Risbec. Figure 8. Lasallegrion koebelei, female.( a), head, dorsal; ( b), head, frontal; ( c), lower face, detail; ( d), mesosoma, dorsal (arrows indicate notauli in their posterior part); ( e), right hind leg, outer aspect; ( f), left fore wing, ventral. Metasoma. petiolus quadrate to subquadrate with fine transverse medioventral carina ( Figure 9i). Metasomal tergites dorsally and laterally with faint imbricate sculpture, and sparsely and unevenly covered with only few long setae. Gt 1–4laterally and dorsomedially emarginate.
Recognition.In the key of Grissell (1995) Lasallegrionwould key out as PodagrionSpinola(in couplet 14) but Lasallegriondiffers from Podagrionas well as from the other Podagrioninigenera by the anteriorly sharply carinate pronotal collar, which is not carinate in all other genera. Lasallegrionalso differs from other Podagrioniniby a characteristic propodeal surface sculpture ( Figures 6d, 8d, 11e, 12e). In all other Podagrionini, three basic propodeal states can be found that are all very different from the structure seen in Lasallegrion. Palmonhas no carination on propodeum, Iridophagoidesis characterised by having almost no carination on the disc of propodeum except posterior lateral vestigial carinae, and Mantiphaga, Podagrion, Micropodagrion, Podagriomicronand Podagrionellahave reversed V or U-shaped carina. Further Propachytomoideshave no carination but exhibits a flattened median plate and Iridophagahas strongly curved, lyriform carinae delimiting a subelliptic median area. Lasallegrioncan be further distinguished from Palmon, Podagrion, Micropodagrionand Mantiphagaby the condition of the metadiscrimen of the metepisternum. Lasallegrionhas a median strip delimited by irregular submedian ridge (metadiscrimen is broader, with one median or two submedian carinae in Palmon, Podagrionand Micropodagrionand broader and more sclerotised in Mantiphaga, Figure 7a–e). Almost all genera of Podagrionini, excluding Lasallegrionand Mantiphaga, share a metepimeron with a polished median area without setation. The metepimeron in Mantiphagais less elongate than in Lasallegrionand anteriorly bent. In Micropodagrionand Palmonthe metepimeron is very broad, in Palmonit is almost as broad as long. In Propachytomoidesthe mesepimeron is bulged outwardly and raised as a flange above the surface of the metapleuron. Figure 9. Lasallegrion koebelei, intermediate (a – c, e, g, h, j), heteromorph (d, f, k) and homeomorph (i) male. ( a), head, dorsal; ( b), antenna, lateral; ( c), head, frontal; ( d), left midtibia and midtarsus, outer aspect; ( e), right hind leg, outer aspect, intermediate male; ( f), right hind leg, outer aspect, heteromorph male; ( g), mesoscutellum and propodeum, dorsal; ( h), part of propodeum and petiolus, dorsolateral; ( i), propodeum and petiolus, dorsal; ( j), propodeum and petiolus, dorsal; ( k), propodeum and petiolus, dorsal. Furthermore, Podagrionella, Iridophagaand Iridophagoideshave the apex of the metatibia expanded in a curved long spine, much longer than that of Lasallegrion, and Palmonis characterised by the complete setation of the fore wing, an autapomorphy of the genus. Females of Podagrionusually do not have the antennal clava distinctly 3–segmented in combination with a narrow line of micropilosity on apical claval segments two and three. Grissell (1995)already stated that P. koebelei(now transferred to Lasallegrion) might need to be transferred from Podagrioninto a new genus. He already noticed the sharply margined pronotal collar, the 3 segmented filiform clava and the narrow strip of micropilosity on apical claval segment 2 and 3 and noted that these characters are different from both Podagrionand Palmon. However, because he apparently knew that some of those characters (segmentation of clava and condition of micropilosity on apical claval segment) are rather homoplastic within Podagrionini, he did not follow up on this, and the presumed new genus has not been described to date. Further, Janšta et al. (2018)mentioned ‘PJAN1079 Podagrionini n. gen.sp. Australia’ as an undescribed genus from Australia. In their phylogenetic analysis, it was inferred as sister group (but with almost no support) of two Mantiphagaspecies. Sequence of COI ( MF956323) of this specimen is highly similar to the COI sequences of specimens of morphospecies 1 group B. The present study confirms the findings of Grissell (1995)and Janšta et al. (2018)and adds several generic diagnostic characters, which corroborate the present designation of Lasallegrion.