Arpactophilus tiri, Breitkreuz, Laura C. V., Ohl, Michael & Engel, Michael S., 2016

Breitkreuz, Laura C. V., Ohl, Michael & Engel, Michael S., 2016, A review of the New Caledonian Arpactophilus (Hymenoptera: Crabronidae), Zootaxa 4063 (1), pp. 1-66 : 47-50

Arpactophilus tiri sp. nov.

( Figs. 101–102 )

Diagnosis. Arpactophilus tiri is the only New Caledonian species in the genus with a greatly narrow and elongate head and body ( Figs. 101, 102 ), and can also be distinguished by the combination of a forewing with two submarginal cells of which the second is triangular (or almost triangular) but not stalked and a metasoma concolorous with the mesosoma. Other distinctive features are the inconspicuous frontal carina that is largely effaced over much of the frons ( Fig. 101 ) and the elongate, mainly finely reticulate structure of the dorsal surface of the propodeum.

Description. FEMALE: Total length 3.3 mm; forewing length 1.8 mm.

Body brown, with areas of light yellow. Light yellow: clypeus; labrum; mandible; palpi; area around mandibular base; antenna; area on apical half of frons ( Fig. 101 ); tegula; fore- and middle leg entirely; hind leg except of area on metafemur. Wings hyaline; pterostigma light brown.

Head about 1.9 × as long as wide in frontal view. Apical margin of clypeus projecting medially, with a scarcely evident, shallow V-shaped incision medioapically ( Fig. 101 ). Apical margin of labrum medially with shallow Vshaped incision. Ventral mandibular tooth about ¼–1/5 of total mandibular length, not reaching opposite mandibular base. Palpal formula probably 2:3 (not completely visible). Frons imbricate with sparse punctation and associated setae. Frontal line largely inconspicuous and largely effaced over much of frons, represented by weak impression on frons and fading towards median ocellus present as faint carina from lower frons to midlength of clypeus, elevated as ridge at basal clypeal margin. Scape 3.2 × as long as wide. Ocellar triangle posterior of tangent between upper posterior orbits of compound eyes, median ocellus posterior of tangent by less than its diameter. Occipital carina interrupted dorsally ( Fig. 6 ). Gena imbricate, punctation and associated setae ventrally denser than laterally, without tubercles, spines, or dorsoventral carina. Hypostomal midventral line carinate with bordering short and fine transverse carinulae on hypostomal integument, not angulate.

Mesosoma about 2.8 × as long as wide in dorsal view. Propodeum about 1.7 × as long as wide in dorsal view. Mesosoma imbricate with dense punctation ( Fig. 102 ), except on propodeum; lateral surface of propodeum finely reticulate; median area of dorsal surface of propodeum finely reticulate (similar to pattern in Fig. 22 ), lateral area transversely carinate. Impressed sulcus present posterior to mesoscuto-mesoscutellar sulcus. Hypersternal sulcus long and slightly pitted. Metafemur 3.8 × as long as wide. Metatibia without differently colored area apically. Pretarsal claws without teeth. Forewing with two submarginal cells; submarginal cell II triangular in one wing, almost so in the other. Hind wing with five distal hamuli.

Metasoma polished with sparse punctation ( Fig. 102 ). Metasomal sternum II without bulge (as in Fig. 1 ). Pygidium with narrow brush of silk setae apically.

MALE: Unknown.

Remarks. Arpactophilus tiri is easily identifiable by its slender body ( Figs. 101, 102 ) which differs from all other species of Arpactophilus species. Some species with only one submarginal cell have an elongate body or head ( A. cemuhi , A. nengone , A. dolichocara ), but never to the extreme observed in A. tiri . No other species from New Caledonia approximates the extreme morphology of A. tiri .

Material examined. HOLOTYPE ♀: “ NEW CALEDONIA 11852: 22°17’S x 166°53’E, 250m, Pic du Grand Kaori, site 2. 22 Nov –22 Dec 2004. Malaise, Burwell, Wright. rainforest [QM].

Etymology. The specific epithet is taken from the name Tiri , one of the New Caledonian native languages. It is treated as a noun in apposition.

Figures

FIGURES 101 – 106. Facial views and lateral habitus of ♀ holotypes (except for Arpactophilus webbi Bohart) of species of Arpactophilus Smith. 101. A. tiri sp. nov., facial view; 102. A. tiri, lateral habitus; 103. A. vamale sp. nov., facial view; 104. A. vamale, lateral habitus; 105. A. webbi, facial view; 106. A. webbi, lateral habitus.

FIGURES 5 – 9. Head and metatibial details of New Caledonian Arpactophilus Smith. 5. Schematic view of posterior of head of Arpactophilus, arrow indicates complete occipital carina; 6. Schematic with arrow indicating incomplete, dorsallyinterrupted occipital carina; 7: Metatibia of holotype ♀ of A. xaragure sp. nov., arrow indicating slightly differently colored but not differently-structured area apically; 8. Metatibia of holotype ♀ of Arpactophilus orowe sp. nov., arrow indicating differently colored and structured area apically; 9. Metatibia of paratype ♀ of A. orowe, scanning electron micrograph with arrow indicating concave area apically.

FIGURES 16 – 22., Dorsal surfaces of ♀ of species of Arpactophilus Smith. 16. Arpactophilus concavus Bohart; 17. A. irwini Bohart; 18. A. kumak sp. nov. (holotype); 19. A. merle sp. nov. (holotype); 20. A. caac sp. nov. (holotype); 21. A. kraussi Bohart; 22. A. propodealis Bohart.

FIGURES 1 – 4. Line drawings of metasomata and forewings of New Caledonian species of Arpactophilus Smith. 1. Metasoma in profile of ♀ of Arpactophilus merle sp. nov., arrow indicates unmodified metasomal sternum II; 2. Metasoma in profile of ♀ of A. irwini Bohart, arrow indicates ventrally swollen metasomal sternum II. 3. Forewing of ♀ of A. irwini; ps: pterostigma, sz I: submarginal cell I, sz II: submarginal cell II. 4, Forewing of ♀ of A. caledonicus Bohart; ps: pterostigma, sz I: submarginal cell I.