Cyrtorhyssa moellerii (Bingham, 1898)

Chansri, Kittipum, Somsiri, Kanoktip, Quicke, Donald L. J. & Butcher, Buntika A., 2023, First confirmed parasitism of pleasing fungus beetles (Coleoptera, Erotylidae) by a tropical rhyssine ichneumonid, and first record for Cyrtorhyssa moellerii Bingham (Hymenoptera, Ichneumonidae) from Thailand, Journal of Hymenoptera Research 96, pp. 783-804 : 783

Cyrtorhyssa moellerii

Material examined.

Five females, twenty males. Thailand, Nakhon Ratchasima, Wang Nam Khiao district, Udom Sap subdistrict, Sakaerat Environmental Research Station , dry evergreen forest, 14°29.8'N, 101°54.96'E, 496 m, aerial net, col. K. Chansri (CUMZ) (1♀ 27.i.2021, 1♀ 28.i.2021, 2♀ 15.ii.2021, 1♀ 16.ii.2021, 2♂ 21.i.2021, 2♂ 22.i.2021, 2♂ 23.i.2021, 2♂ 24.i.2021, 1♂ 25.i.2021, 1♂ 27.i.2021, 1♂ 29.i.2021, 5♂ 8.ii.2021, 1♂ 15.ii.2021, 3♂ 25.ii.2021) .

Diagnosis.

Cyrtorhyssa moellerii is clearly different from C. xishuangensis in which face with black longitudinal line. In addition, frons of C. xishuangensis has a tapered ridge rather than distinct carina, and female fore wing has no areolet. Cyrtorhyssa moellerii can be separated from C. mesopyrrha because the fore wing areolet of C. moellerii , when present, is quite short, whereas the fore wing areolet of female C. mesopyrrha is wider (Kamath and Gupta, (1972). The ground colour of tergites 1-3 of female C. moellerii is black with yellow bands, while in female C. mesopyrrha it is reddish without yellow bands.

Description.

Female (Figs 5 , 6 ). Body length, mean = 38.0 mm (range = 36.5-39.0 mm); fore wing length, mean = 27.8 (range = 27.0-28.0 mm); ovipositor sheath length, mean = 40.5 mm (range = 40.0-41.0 mm) (Fig. 5A ).

Head. Antenna with 40-41 flagellomeres, terminal flagellomere acuminate; face strongly, transversely striated on its upper 0.6, lower 0.3 coarsely punctate, interspaces 0.5 their diameter, towards orbits punctures finer and sparser; clypeus minutely, finely punctate, broadly concave at apex (Fig. 5B ); malar space mat, 0.4 × basal width of mandible (Fig. 5C ); frons smooth, subpolished with a median carina and with a semicircular groove around ocellar triangle bordered laterally by fine striations; vertex with a few scattered punctures, smooth and polished; interocellar distance 0.5 ocello-ocular distance; occiput without a median groove dorsally (Fig. 5D ). Occipital carina absent medio-dorsally.

Mesosoma. Mesoscutum coarsely transversely scutellum rugose, notauli meeting approximately 0.4 distance from anterior of mesoscutum; scutellum strongly, coarsely punctate; median area of metanotum smooth and polished (Fig. 6A ); mesopleuron sparsely punctate, punctures on lower 0.3 separated by 2-3 × their diameter, epicnemium with more crowded punctures, interspace 0.5-1.0 their diameter; epicnemial carina weakly curved towards anterior edge, about 0.6 the height of mesopleuron; mesosternum coarsely punctate, punctures sometimes coalescent; metapleuron punctate, interspaces 1-2 × their diameter (Fig. 5E ); propodeum largely smooth and polished, with very sparse, minute punctures dorsally, dorsolateral corners and lateral sides shallowly punctate, interspace 4-6 × their diameter, broadly depressed at extreme base in middle, and medially with a distinct, shallow groove on basal 0.8 (Fig. 6A, C ).

Wing. Areolet of fore wing short triangular, lengths of veins 2RS (=2rs-m): 1M: rs-m (= 3rs-m) = 0.6: 0.8: 1.0; vein 2m-cu joining M interstitial with rs-m (= 3rs-m) (Fig. 6B ).

Metasoma. First tergite smooth and shiny 2.1 × its apical width; second tergite weakly mat at base, with few scattered punctures; third tergite with basal 0.5 distinctly punctate medially, interspace 0.5-1 × diameter of punctures, rest smoother (Fig. 6C, E ); fourth tergite with basal 0.5 coarsely punctate, elsewhere punctures minute, becoming smoother towards apex with moderately dense, brownish pubescence; basal 0.7 of fifth and following tergites punctate, punctures becoming finer on succeeding segments and with dense brownish pubescence (Fig. 6D, E ); ovipositor sheath 2.1 × the length of fore wing.

Coloration. Black. Face and clypeus yellow, malar area black; mandibles basally reddish-brown with a yellow macula in middle, teeth black; malar space black; temple yellow; frons with two broad lateral spots touching eye margin, median carina on frons yellow; antenna with scape yellowish in front, flagellum dark brown; occiput largely yellow, dorsally black; pronotum, yellow with black band curving from postero-ventral to anterior margin, and anteriorly pointed mediodorsal mark; mesoscutum black with narrow yellow mark alongside notauli medially; tegula, subtegular tubercle and anterior 0.5 of mesopleuron, and metapleuron with posterior 0.6 including tubercle, yellow; axillae yellow, scutellum, with yellow patch antero-medially; metascutellum black except for small yellow spot medio-dorsally; propodeum yellow except extreme dorsolateral corners, spiracular region and extreme apical margin, black; fore legs yellow ventrally from coxa to tibia, coxa dorsally black; middle leg, coxa black with yellow dorsal patch, trochanter black except small dorsal yellow spot, and brownish distal margin, trochantellus black with brownish dorsal part, tibia without apical black, femur black basally, apical 0.3, tibia yellow with dorsal blackish mark on basal 0.5, tarsus black; hind legs as middle leg except trochanter largely yellow, tibia black with medial 0.3 brown-yellow around subgenual organ, femur with narrow longitudinal yellow line except basal 0.1; wings yellowish-hyaline with apical margins infuscate; stigma brownish and vein dark brown; metasomal tergites black with the following yellow: tergite 1 subposterior dorsal patch, tergites 2 and three, complete (except laterally) transverse subposterior band, tergites 4 and 5 with large triangular sub posterior patches, tergite 6 large lozenge-shaped postero-dorsal patch, tergite 7 broad yellow posterior transverse band. Ovipositor sheaths black with reddish tinge.

Male (Figs 7 , 8 ). Body length, mean = 23.9 mm (range = 14.0-32.0 mm); fore wing length, mean = 16.8 mm (range = 11.5-24.0 mm) (Fig. 7A ).

Head. Antennae with 34-41 flagellomeres, terminal flagellomere acuminate; face strongly transversely striated on its upper 0.8, lower 0.2 coarsely punctate, interspaces 0.5 their diameter, towards orbits punctures finer and sparser; clypeus minutely, finely punctate, broadly concave at apex (Fig. 7B ); malar space mat, 0.6 × basal width of mandible (Fig. 7D ); frons smooth, subpolished with a median carina and with a semicircular groove around ocellar triangle, vertex with a few scatter punctures, smooth and polished; interocellar distance 0.5 × ocello-ocular distance; occiput without a median groove dorsally (Fig. 7C ).

Mesosoma. Scutellum strongly, coarsely punctate; median area of metanotum smooth and polished (Fig. 7F ); mesopleuron sparsely punctate, punctures on lower 0.3 separated by 2-3 × their diameter, epicnemium with more crowded punctures, interspace 0.5-1.0 × diameter; epicnemial carina weakly curved towards anterior edge, about 0.5 the height of mesopleuron; mesosternum coarsely punctate, punctures sometime coalescent; metapleuron punctate, interspaces 1-2 × their diameter (Fig. 7E ); propodeum largely smooth and polished, with very sparse, minute punctures dorsally, dorsolateral corners and lateral sides shallowly punctate, interspace 4-6 × their diameter, broadly depressed at extreme base in middle, and medially with a distinct, shallow groove on basal 0.8 (Figs 7F , 8C ).

Wing. Areolet of fore wing short triangular, length of veins 2RS (=2rs-m): 1-M: rs-m (=3rs-m) = 0.6: 0.8: 1.0 (Fig. 8A ) or absent (Fig. 8B ); vein 2m-cu joining M interstitial with rs-m (= 3rs-m).

Metasoma. First tergite smooth and shiny 2.0 × its apical width (Fig. 8C ); second and third tergites smooth and polished with few scattered punctures; fourth tergite with basal 0.2 coarsely punctate, elsewhere punctures minute, becoming smoother towards apex with moderately dense, brownish pubescence; fifth to seventh third tergites smooth and polished with few scattered punctures with dense brownish pubescence (Fig. 8D, E ).

Coloration. Yellow. Mandibles basally with brownish and with a yellow macula in middle, teeth black; malar space brownish-yellow; frons with two broad lateral spots touching eye margin, antenna with scape yellowish in front, flagellum dark brown; occiput dorsally brownish; pronotum, yellow with a curved incomplete black band dorsally and with a reddish-brown stripe in centre; median and lateral lobe of mesoscutum reddish-brown, posterior of merging notauli extending into a black midlongitudinal stripe; scutellum largely dull yellow with posterior 0.2 of piceous; median area of metanotum yellow; tegula, epicnemium, posterior transverse carina of mesosternum, juxtacoxal carina black; propodeum yellow except extreme dorsolateral base, spiracular region and extreme apical margin black; Legs yellow with tarsi gradually infuscate towards apex except: fore femur ventrally brown; fore tibia narrowly brown dorsally on basal 0.7, fore; middle leg similar to fore leg except dark mark on femur on medial side; hind coxa ventrally black, hind femur brown-black basally and medioventrally, hind tibia dorsally with basal 0.5 and distal 0.2 posteriorly dark brown; wing yellowish-hyaline with apical margin infuscate, stigma brownish and vein dark brown; metasomal tergites black with yellow marks as follows: tergite 1 with large, sub-posterior yellow patch, tergites 2 and 3 with broad sub-posterior yellow bands, tergite 4 with yellow patches mediolaterally.

Comment.

Male and female of the C. moellerii display sexual dimorphism with different colour patterns. Fore wing areolet of female always present according to the keys to species of this genus by Kamath and Gupta, (1972) (Fig. 6B ), however, male of C. moellerii shows variation of fore wing areolet, either present of absent (Fig. 8A, B ) same as male C. mesopyrrha ( Kamath and Gupta 1972).

Figures

Figure 5. Light micrograph of female C. moellerii dorsal view of habitus (A), face (B), lateral view of head (C), dorsal view of head (D), lateral view of mesosoma (E).

Figure 6. Light micrograph of female C. moellerii dorsal view of mesosoma and propodeum (A), fore wing (B), dorsal view of propodeum (C), lateral view of metasoma (D), dorsal view of metasoma (E), ventral view of metasoma (F), lateral view of ovipositor (G).

Figure 7. Light micrograph of male C. moellerii dorsal view of habitus (A), face (B), dorsal view of head (C), lateral view of head (D), lateral view of mesosoma (E), dorsal view of mesosoma and propodeum (F).

Figure 8. Light micrograph of male C. moellerii fore wing areolet present morph (A), fore wing areolet absent morph (B), dorsal view of propodeum (C), lateral view of metasoma (D), dorsal view of metasoma (E), ventral view of metasoma (F).