Heydenia longipetiolata Hemanth & Gupta, 2025

Heydenia longipetiolata Hemanth & Gupta sp. nov.

( Figs 1–7 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 , 8A View FIGURE 8 )

Material examined. Holotype (female on card): INDIA: Karnataka, Madikeri, Kabbinakad, Chingaara estate, 10.i.2025, ex. Larva of Agrilus sp. on Villebrunea integrifolia Gaud. , coll. Hemanth, accession number: NIM/ NBAIR/HEYD/HEYD/10125-H ( NIM).

Paratypes: same data as holotype, accession numbers: NIM/NBAIR/HEYD/HEYD/10125-P1 ( NIM)‒NIM/ NBAIR/HEYD/HEYD/10125-P3 ( NIM) ( 2♀ and 1♂ on three cards). Karnataka, Melinajuganahalli, Doddaballapura , 20.vii.2025, ex. Larva of Agrilus sp. on Albizia amara (Roxb.) Boivin. , coll. Hemanth, accession numbers: NIM/ NBAIR/HEYD/HEYD/20725-P4 ( NIM)‒NIM/NBAIR/HEYD/HEYD/20725-P16 ( NIM) ( 7♀ and 6 ♂ on thirteen cards) .

Diagnosis. Female, body length 4.4–7.5 mm; face with iridescent lanceolate setae ( Fig. 2A View FIGURE 2 ); POL 0.95–1.20× OOL; gena uniformly reticulate ( Fig. 2C View FIGURE 2 ); antenna with clava subequal to combined length of preceding two segments ( Fig. 2B View FIGURE 2 ); mesosoma moderately compressed dorsoventrally ( Figs 1B View FIGURE 1 , 8A View FIGURE 8 ); lateral panels of pronotum angled at about 45° to the dorsal surface, with a punctate region as in Fig. 2F View FIGURE 2 ; axillae uniformly reticulate ( Fig. 2F View FIGURE 2 ); dorsellum smooth, shiny and punctate dorsally ( Fig. 3A View FIGURE 3 ); propodeum distinctly reticulate-punctate ( Fig. 3A View FIGURE 3 ) to variably sculptured ( Fig. 5B, C View FIGURE 5 ), plical region with median carina distinct only in posterior half, shallowly merging with plical region in anterior half ( Figs 3A View FIGURE 3 , 5B, C View FIGURE 5 ); fore leg with profemur distinctly enlarged with distinct basal ventral angle and minute serrations, protibia with stout spines on dorsal margin ( Fig. 2E View FIGURE 2 ); fore wing basal cell with basal setal line present, infuscation near STV broad ( Fig. 3C View FIGURE 3 ); petiole conspicuous, 1.4–1.5× longer than wide, Gt 1 and Gt 2 with posterior margins distinctly incised medially ( Fig. 3D View FIGURE 3 ); ovipositor sheath 1.9–2.0× length of metatibia ( Figs 1B View FIGURE 1 , 8A View FIGURE 8 ).

Description. FEMALE ( holotype): body length 6.0 mm, ovipositor sheath length 2.4 mm.

Color: mandible black; tegula blackish brown; scape bicolored, rest of the antenna uniformly blackish brown; legs black with basal and apical margins of femora and tibiae faintly yellowish, protarsus honey brown, meso- and metatarsi whitish with apex slightly darker; head greenish with bluish and golden metallic luster, face darker than gena and with lanceolate setae on face silvery and iridescent; mesosoma mostly with greenish blue metallic luster; pronotum anteriorly, mesoscutum in median anterior half between notauli, axillae in anterior half and scutellum with strong dark coppery metallic luster; under strong illumination lateral panels of pronotum, sides of mesoscutum, axillae in posterior half, prepectus, and mesopleuron and metapleuron in posterior half with bluish metallic luster; lateral panel of pronotum posteriorly with dark brownish coloration ( Fig. 2F View FIGURE 2 ); dorsellum with golden green metallic luster; propodeum with bluish and golden green metallic luster; wings hyaline and slightly iridescent; fore wing with discal setae and thick tuft of setae at base of parastigma and MV black; fore wing veins with MV and parastigma pale brown, SMV (excluding parastigma), PMV and STV darker; metasoma mostly black with faint purple tinge, with metallic luster on Gt 4 –Gt 6; petiole testaceous and ovipositor sheaths black.

Head: mostly reticulate, in frontal view 1.17× wider than long; face above scrobe, around median ocellus, distinctly shallowly reticulate, scrobe reticulate-strigose, bell shaped; distance between interantennal region 1.66× distance from torulus to nearest eye margin; parascrobal region, interantennal region and lower face with lanceolate setae; head in dorsal view 1.75× wider than long; POL subequal to OOL ( Fig. 2D View FIGURE 2 ); temple narrow; malar sulcus distinct ( Fig. 2C View FIGURE 2 ); antenna with fl 1 transverse, fl 2 shorter than fl 3, fl 3 equal to combined length of fl 1 and fl 2, fl 3 and fl 4 almost equal to each other, rest of the segments decreasing in length towards apex, clava subequal to combined length of preceding two segments ( Fig. 2B View FIGURE 2 ).

Mesosoma: reticulate-punctate, moderately dorsoventrally compressed ( Figs 1B View FIGURE 1 , 8A View FIGURE 8 ); pronotum long, tent like with lateral panels angled at about 45° to the dorsal surface, and smooth and shiny except for a punctate region as in Fig. 2F View FIGURE 2 ; mesoscutum 1.2× as wider as long, notauli complete and weakly indicated; scutellum 1.12× as wide as long, reticulation closer and with a differentiated axillula; scutellum without frenum, frenal arm indicated laterally; dorsellum shiny and punctate dorsally ( Fig. 3A View FIGURE 3 ), metanotum faintly reticulate laterally; propodeum ( Fig. 3A View FIGURE 3 ) with plical region distinctly reticulate-punctate, slightly irregularly rugose anteriorly, with median carina distinct only in posterior half and shallowly merging with cuticle surface in anterior half, and with distinct, almost parallel plicae; propodeal callus anteriorly with two interconnected smooth and shiny broad fovea, with reticulate-punctate region and setation as in Fig. 3A View FIGURE 3 ; propodeal spiracles inside a smooth and shiny area, with distance between spiracles 1.2× medial length of propodeum; prepectus triangular and setose; mesopleuron ventrally setose, distinctly reticulate-punctate with acropleuron smooth, shiny and faintly aciculate, upper mesepimeron turning aciculate posteriorly ( Fig. 3B View FIGURE 3 ); metapleuron punctate and setose; fore wing hyaline except for infuscation near STV, the infuscation narrow anteriorly and broadening towards the posterior wing margin, 3.3× as long as wide, with costal cell setose, basal cell bare with basal setal line present and cubital setal line incomplete, speculum present ( Fig. 3C View FIGURE 3 ), marginal fringe minute, and MV 1.3× PMV, PMV 2.2× STV; profemur and metacoxa with aciculate sculpture represented by longitudinally impressed lines; fore leg with profemur distinctly enlarged, ventral margin basally angled, with minute serrations ( Fig. 2E View FIGURE 2 ), protibia with distinct stout spines on dorsal margin (one at distal margin) and with protibial spur curved, and basitarsus slightly curved and more conspicuous than rest of tarsal segments; midleg with mesotibial spur longest of all spurs; hind leg with metacoxa with moderately long setae, and metatibia with two unequal spurs.

Metasoma: only slightly longer than mesosoma (1.1×); petiole oval shaped, 1.45× as long as wide ( Fig. 3D View FIGURE 3 ); Gt 1 –Gt 3 smooth and shiny, Gt 1 and Gt 2 with posterior margins distinctly incised medially; Gt 4 –Gt 6 reticulate, reticulation on Gt 4 weak and faintly visible; ovipositor sheath shorter than metasoma, in lateral aspect 1.9× length of metatibia ( Figs 1B View FIGURE 1 , 8A View FIGURE 8 ).

MALE. Similar to female but body length 4.65 mm; POL 1.1× OOL ( Fig. 4B View FIGURE 4 ); antenna with clava slightly longer (1.2×) than combined length of preceding two segments ( Fig. 4C View FIGURE 4 ); metasoma with petiole distinctly elongate, 3× as long as wide ( Fig. 4H View FIGURE 4 ), remaining segments 3.5× medial length of petiole; Gt 1 with posterior margin medially incised, Gt 2 concealed under Gt 1 with posterior margin straight ( Fig. 4G View FIGURE 4 ).

Variation. Females: body length 4.4–7.5 mm (n=10, including holotype); POL 0.95–1.20× OOL; propodeum with plical region distinctly reticulate-punctate ( Fig. 3A View FIGURE 3 ) or with reticulation incompletely/completely reduced with irregular transverse rugae ( Fig. 5B, C View FIGURE 5 ), propodeal callus below the level of spiracles distinctly reticulate-punctate ( Fig. 3A View FIGURE 3 ) or irregularly rugose with reticulation reduced ( Fig. 5B, C View FIGURE 5 ); fore wing 3.1–3.3× as long as wide, basal cell with cubital setal line incomplete to complete, MV 1.2 – 1.4 × PMV, PMV 2.1 View Materials – 2.3 View Materials × STV; petiole 1.4–1.5× as long as wide, ovipositor sheaths 1.9–2× length of metatibia. Males: body length 2.2–5.5 mm (n=7); all legs including coxae but excluding tarsi blackish ( Fig. 1C View FIGURE 1 ) to uniformly testaceous ( Fig. 1D View FIGURE 1 ); POL 1.10 – 1.65 × OOL; propodeum with median carina distinct either in posterior half ( Fig. 4D View FIGURE 4 ) or in posterior two thirds ( Fig. 5A View FIGURE 5 ); fore wing with infuscation near STV broad ( Fig. 4F View FIGURE 4 ) or nearly rectangular ( Fig. 5D View FIGURE 5 ) to distinctly reduced or absent ( Fig. 5F View FIGURE 5 ); petiole 2.85–3.10× as long as wide .

Biology. Larval parasitioid of Agrilus spp. ( Coleoptera : Buprestidae ) infesting dead branches of Villebrunea integrifolia Gaud. ( Urticaceae ) ( Fig. 7A View FIGURE 7 ) and Albizia amara (Roxb.) Boivin. ( Fabaceae ) ( Fig. 7D View FIGURE 7 ). Individuals of H. longipetiolata ( Fig. 8A View FIGURE 8 ) were first recorded emerging from branch cuttings of V. integrifolia infested with Agrilus sp. 1 ( Fig. 7C View FIGURE 7 ) collected from Madikeri, Karnataka. A total of three females and one male of H. longipetiolata and more than thirty individuals of Agrilus sp. 1 emerged from the branch cuttings. During the second encounter with the same species in July 2025, several individuals of H. longipetiolata ( Fig. 6A, B View FIGURE 6 ) were observed inspecting dead branches of A. amara in Doddaballapura, Karnataka. During subsequent visits to the same location, females of H. longipetiolata were seen ovipositing ( Fig. 6D View FIGURE 6 ) and several males were observed approaching females ( Fig. 6C View FIGURE 6 ) on dead branches of A. amara . The branches had a large number “D” shaped exit holes ( Fig. 6I View FIGURE 6 ) characteristic of Agrilus beetles and one individual of Agrilus sp. 2 ( Figs 6G View FIGURE 6 , 7F View FIGURE 7 ) was observed emerging from the dead branch. Upon collecting the infested branch, part of it was carefully split open and several pupae of H. longipetiolata along with host remains ( Fig. 6F View FIGURE 6 ) and adults of Agrilus sp. 2 were recovered. A total of fifteen individuals (ten females and five males) of H. longipetiolata and more than twenty adults of Agrilus sp. 2 emerged from the sampled branch cuttings of A. amara .

Distribution. India: Karnataka (Doddaballapura and Madikeri).

Etymology. The species name (adjective) refers to the remarkable and distinctly long petiole of the male, which is comparatively longer than most other species of Heydenia .

Comments. Females of H. longipetiolata can be readily differentiated from other Indian species ( H. indica , H. gibsoni , H. kashmirensis and H. tuberculata ) and Chinese species ( H. angularicoxa , H. coomoni Xiao & Huang, 2002 , H. scolyti Yang, 1996 and H. testacea ) in having the mesosoma moderately compressed dorsoventrally, propodeum with plical region distinctly reticulate-punctate or with reticulation incompletely to completely reduced with irregular transverse rugae, with median carina distinct in posterior half and shallowly merging with the cuticle surface in the anterior half, propodeal callus below the level of spiracles distinctly reticulate-punctate ( Fig. 3A View FIGURE 3 ) or irregularly rugose with reticulation reduced ( Fig. 5B, C View FIGURE 5 ), fore wing with basal setal line present, profemur distinctly enlarged with basal ventral angle, and ovipositor sheath 1.9–2× the length of metatibia. Females are similar to those of H. trinodis Bouček, 1988 , described from Papua New Guinea, in having a flat scutellum. They differ from H. trinodis in having the axillae reticulate, the plical region with the median carina distinct in its posterior half and shallowly merging with the surface in its anterior half, the petiole 1.4–1.5× as long as wide, and the ovipositor sheaths 1.9–2.0× the length of metatibia (in H. trinodis the axillae shiny and almost smooth, plical region with sharp median carina, petiole about 2× as wide as long, and ovipositor sheaths about 1.2× length of metatibia). Females differ from those of H. longicollis Cameron, 1912 , described from Australia, H. pretiosa , described from Europe, and H. unica Cook & Davis, 1891 , described from USA, in having a longer ovipositor sheath, 1.9–2.0× the length of metatibia (in H. longicollis , H. pretiosa and H. unica the ovipositor sheath is rather short, 0.1–0.3× the length of the metatibia). Individuals are separated from H. mateui Hedqvist, 1967 , described from Chad, in having the plicae distinct and complete on the propodeum, the fore wing with the costal cell setose, and the metatibia with two unequal spurs (in H. mateui , propodeum with plicae reduced, indicated posteriorly, fore wing with costal cell bare, and metatibia with a single spur). Males of H. longipetiolata can be differentiated from those of H. natalensis, Westwood, 1874 , described from South Africa, in having the antennal flagellomeres uniformly black, and the petiole 3× as long as wide (in H. natalensis , antennae with fl 5 –fl 5 lighter in color than rest of the segments, and petiole very short). Males are similar to those of H. madagascariensis, Hedqvist, 1961 , described from Madagascar, in possessing a long petiole, but can be differentiated by having the propodeal plical region with the median carina distinct in its posterior half to two thirds, the fore wing basal cell with a basal setal line, and the infuscation near the stigmal vein small (in H. madagascariensis , the propodeal plical region with a complete median carina, fore wing with basal cell bare, and infuscation near STV broad, reaching the posterior wing margin).