Chalcidid parasitoids (Hymenoptera: Chalcididae) of Opisina arenosella (Walker) (Lepidoptera: Xyloryctidae) on coconut palm in southern India Author Binoy, C. Independent researcher, Sreeragam, Chereekandy, Elathur, Kozhikode Kerala- 673303, India. Author Nivetha, S. 0009-0002-4102-911X sekarnivi25112000@gmail.com Author Arulprakash, R. 0009-0002-4102-911X sekarnivi25112000@gmail.com text Zootaxa 2024 2024-11-12 5537 4 493 510 http://dx.doi.org/10.11646/zootaxa.5537.4.3 journal article 10.11646/zootaxa.5537.4.3 1175-5326 14240326 26BA78B1-2B0D-4560-A393-1DC1C8E5342E Key to chalcidid species parasitizing pupae of the black headed caterpillar 1. Metatibia apically almost perpendicularly truncate and with two spurs (e.g. Figs 16 , 25 , 52 , 56 , 60 ) [ Haltichellinae ]....... 2 – Metatibia apically obliquely truncate, forming a subtriangular or elongate stout spine produced well beyond insertion of tarsus, and with one spur (e.g. Figs 29 , 33 , 39 , 42 , 48 ) [ Brachymeriinae ].............................................. 10 2. Marginal vein more or less on wing margin, pmv present (occasionally stub-like), and stv distinctly developed (e.g. Figs 121, 19, 23, 49) ( Haltichellini ).............................................................................. 3 – Marginal vein short and distinctly removed from anterior wing margin, pmv absent, and stv usually rudimentary ( Fig. 58 ) [metafemur with a massive basal tooth followed by long comb of serrulation, densely setose ( Fig. 60 )] ( Hybothoracini )........................................................................... Psilochalcis carinigena (Cameron) 3. Metatibia externally without additional outer carina within distal half (e.g. Figs 16 , 21 , 23 , 56 )........................ 4 – Metatibia externally with additional outer carina within distal half ( Fig. 52 , arrow) [scutellum apically distinctly bidentate with two large lobes ( Fig. 50 ); fore wing with infumation darkest behind mv ( Fig. 49 ); Gt 1 dorsally with two basal carinae ( Fig. 53 )]................................................................... Haltichella macrocera (Waterston) 4. Ventral margin of metafemur with uni- or bilobed serrulation (e.g. Figs 16 , 21 , 25 )................................. 5 – Ventral margin of metafemur with tri-lobed serrulation ( Fig. 56 ) [pronotal carina indistinct at least laterally and pronotum without medial tubercles ( Fig. 57 ); fore wing with two distinct brown regions separated by hyaline spot ( Figs 54, 57 ); metafemur brown with apex red-brown; metatibia red-brown] ( Fig. 56 ).................. Kriechbaumerella destructor (Waterston) 5. Face with conspicuous and complete horse-shoe shaped carina (e.g. Figs 13 , 20 ); pronotal carina distinct and with strong to weak medial tubercles (e.g. Figs 14 , 22 ) [Genus Antrocephalus Kirby ]........................................... 6 – Face without horse-shoe shaped carina; pronotal collar without carina or tubercles [fore wing with a clear white spot with white pubescence near stv ].......................................................... Hockeria opisinae Narendran 6. Preorbital carina joining auricular carina ( Figs 13 , 20 , arrow).................................................. 7 – Preorbital carinae not joining auricular carina............................................................... 8 7. Metacoxa with weak dorsobasal tubercle; metafemur with an inner basal tooth/tubercle ( Fig. 17 , arrow); scutellum ending in a medially notched or strong emargination................................... Antrocephalus hakonensis (Ashmead) – Metacoxa with prominent dorsobasal tubercle ( Fig. 21 , arrow); metafemur without an inner basal tooth/tubercle; scutellum apically bilobed, with a narrow emargination between the lobes ( Fig. 22 , arrow)........... Antrocephalus lugubris (Masi) 8. Gastral tergum 1 with two carinae basally ( Fig. 26 , arrow).................................................... 9 – Gastral tergum 1 without carinae basally [fore wing with faint black infumation near mv extending to middle; pmv 1.5× mv ]..................................................................... Antrocephalus maculipennis Cameron 9. Fore wing with brown spot or regions adjoining mv ; pronotal carina distinct, forming tubercles medially; pmv as long as mv ...................................................................... Antrocephalus cariniceps (Cameron) – Fore wing infumate, without distinct brown spots or regions ( Fig. 23 ); pronotal carina indistinct, pronotal tubercles absent; pmv 1.2× as long as mv ..................................................... Antrocephalus phaeospilus Waterston 10. Metafemur without an inner basal tooth/tubercle (e.g. Figs 36 , 40 )............................................. 11 – Metafemur with an inner basal tooth/ tubercle ( Fig. 45 , arrow) [metafemur angulate dorsally, usually red with apex yellow ( Fig. 48 ) ..................................................................... Brachymeria podagrica (Fabricius) 11. Metacoxa with a ventromesal tooth or protuberance [scutellum rounded or weakly bilobed apically; metasoma oval, distinctly shorter than mesosoma; metatibia yellow except black basally].......................... Brachymeria lasus (Walker) – Metacoxa without a ventromesal protuberance (e.g. Figs 33 , 35 , 42 )............................................ 12 12. Postorbital carina absent or indistinct [metasoma acuminate, distinctly longer than mesosoma; mesosoma with dense shallow pits, the interstices weakly carinate; metatibia brownish-black with subbasal and apical yellow regions]........................................................................................... Brachymeria excarinata Gahan – Postorbital carina distinct (e.g. Figs 31 , 38 , arrow).......................................................... 13 13. Preorbital carina distinct (e.g. Figs 37 , arrow, 41)........................................................... 14 – Preorbital carina indistinct/absent [scape reaching median ocellus; median area below scrobe raised, smooth with scattered pits ( Fig. 32 ); mesosoma with close umbilicate pits; metasoma shorter than mesosoma; metafemur yellow with variably large reddish-brown to brownish-black region ( Fig. 33 )]............................. Brachymeria megaspila (Cameron) 14. Postorbital carina reaching genotemporal margin........................................................... 15 – Postorbital carina not reaching genotemporal margin........................................................ 16 15. Area ventral to scrobe with median smooth area; scape reaching median ocellus; metatibia shorter than metafemur ( Fig. 42 )............................................................................... Brachymeria nosatoi Habu – Area ventral to scrobe without such area; scape not reaching median ocellus; metatibia longer than metafemur ( Fig. 39 )............................................................................. Brachymeria nephantidis Gahan 16. Scutellum rounded apically; metasoma globose or sub-globose; metatibia yellow with base brown-black....................................................................................... Brachymeria euploeae (Westwood) – Scutellum emarginate or bilobed apically ( Fig. 30 ); metasoma sub-acuminate; metatibia yellow apically and basally, medially brown ( Fig. 29 ).............................................. .. Brachymeria atteviae Joseph Narendran & Joy