Petiolachertus, Hansson, 2024

Hansson, Christer, 2024, Two new genera of Eulophinae (Hymenoptera: Eulophidae), including four new species parasitoids on Gracillariidae (Lepidoptera) leaf miners in Costa Rica, Zootaxa 5447 (4), pp. 562-572 : 563

Petiolachertus gen. nov.

Type species: Petiolachertus castor sp. nov.

Etymology. The name is from the Latin petiolus = stalk, and from the genus Elachertus , based on the very elongate gastral petiole and the affinity to Elachertus . The gender is masculine.

Diagnosis. Head with postoccipital carina indicated but weak with edge rounded ( Figs 2, 6 ). Eyes strongly hairy ( Figs 4, 7 , 26 ). Mesoscutum with distinct and complete notauli and surface ±covered with evenly distributed setae ( Figs 2, 6 ). Mesoscutellum with strong reticulation and either with large meshes throughout ( Fig. 2 ), or with smaller meshes medially and large meshes along lateral and posterior margins ( Fig. 6 ). Dorsellum excavate with posterior margin raised and with a median carina ( Figs 2, 6 ). Propodeum with a strong and complete median carina ( Figs 2, 6 ). Mesepimeron with a transverse sulcus ( Figs 1, 5 ). Petiole very long and slender ( Figs 3, 6 ), 3.4–3.8× as long as wide, with dorsal surface smooth and shiny, or with very weak small-meshed reticulation. Hind leg with two strong tibial spurs ( Figs 3, 5 ), longest spur as long as basitarsus.

Identification. There are currently no identification tools for the 41 Eulophinae genera hitherto recorded from the Neotropical region, but Petiolachertus is easily identified through the following combination of characters: eyes strongly hairy; mesoscutum with ±distinct and complete notauli and surface ±covered with evenly distributed setae; dorsellum excavate with posterior margin raised and with a median carina; hind leg with longest tibial spur equal in length to basitarsus; gastral petiole very long, 3.4–3.8× as long as wide.

Description. Head with eyes with dense short hairs; malar sulcus present; clypeus undelimited, with ventral margin ±straight; mandibles with two large teeth at apex and with a row of three small teeth above these; antennal scrobes undelimited; without occipital and postoccipital carinae; occipital margin with a sharp edge behind ocelli. Antenna inserted above lower level of eyes, scape not reaching anterior ocellus; male scape very similar to female; with six large flagellomeres: four funiculars and two clavomeres, funiculars with a short peduncle at apex, with one small anellus; male with unbranched flagellomeres. Pronotum ±bell-shaped, with strong reticulation except smooth posterior margin, with ±evenly dispersed setae, without a carina along anterior margin of pronotal collar. Mesoscutum with ±distinct and complete notauli; strongly reticulate and ±evenly covered with strong setae and with two pairs of long and strong setae close to posterior margin. Mesoscutellum with strong reticulation, meshes ±isodiametric; without sublateral grooves; with two pairs of long and strong setae attached on lateral parts, one pair in anterior part and one pair in posterior part. Axillae not advanced forward of transscutal articulation, and not meeting medially. Dorsellum excavate with posterior margin raised and with a median carina. Propodeum with a strong and complete median carina with anterior part triangular and part in front of triangle forming a transverse cup, and with complete plicae; propodeal callus with 6–7 setae in a single row. Mesepimeron with a transverse sulcus. Fore wing with 6–7 setae on dorsal surface of submarginal vein; speculum present and closed below and towards base of wing; costal cell with numerous scattered setae throughout on ventral surface, and with a complete row of setae along margin on dorsal surface; postmarginal vein 1.2× as long as stigmal vein. Hind leg with two tibial spurs, 1.0× and 0.6× as long as basitarsus. Petiole very elongate, 3.4–3.6× as long as wide, smooth and shiny or with very weak reticulation on dorsal surface. Gaster ovate with apex pointed. Apart from internal genital structures the female and male are very similar.

Figures

FIGURES 1–7. Petiolachertus spp. nov., females; 1–4. P.castor; 1holotype,habitus in lateral view; 2paratype, head+mesosoma in dorsal view; 3 paratype, metasoma in dorsal view; 4 holotype, head in frontal view; 5–7. P. pollux; 5 holotype, habitus in lateral view; 6 paratype, habitus in dorsal view; 7 paratype, head in frontal view.

FIGURES 21–26. Petiolachertus & Macroplectron spp. nov.; 21–23. Head in frontal view; 21 M. nishidai, female paratype; 22 M. nishidai, male paratype; 23 M. safron, female holotype; 24–26. Vertex; 24 M. nishidai, female holotype; 25 M. safron, female holotype; 26 P. castor, female holotype.