Allorhogas gallicola Gahan, 1912

Samacá-Sáenz, Ernesto, Egan, Scott P. & Zaldívar-Riverón, Alejandro, 2020, Species Diversity in the Braconid Wasp Genus Allorhogas (Doryctinae) Associated With Cynipid Galls on Live Oaks (Quercus: Fagaceae) Using Natural History, Phylogenetics, and Morphology, Insect Systematics and Diversity 4 (2020), No. 3, pp. 1-20 : 13-15

Allorhogas gallicola Gahan, 1912

( Fig. 8 A–F).

Diagnosis. Allorhogas gallicola can be distinguished from the described species of Allorhogas associated with cynipid galls on live oaks mainly by 1) its larger size (3.0– 4.2 mm; 1.4–3.0 mm in the remaining species), 2) propodeum area enclosed by carinae smooth and polished (rugoseareolate, slightly coriaceous-rugulose or coriaceous-transversally rugulose in the remaining species) and 3) its distinctive longer ovipositor (2.2 times as long as metasoma; approximately as long as metasoma in the remaining species). Allorhogas gallicola can be also differentiated because it was reared from a cynipid twig galls in ‘ Quercus pinifolia ’ ( Gahan 1912) near College Park, Maryland, United States.

Female. Body size 4.2 mm ( Fig. 8A ), forewing 4.0 mm. Color: metasoma and head honey yellow; mesosoma and legs honey yellow to yellow; scape honey yellow to light brown at the base, antennae broken; wings hyaline, stigma brown, veins brown to honey yellow; ovipositor sheaths dark brown.

Head: transverse in dorsal view, 1.9 times wider than its median length ( Fig. 8B ), and 1.5 times wider than high; occipital carina complete, reaching hypostomal carina before base of mandible; POL 1.2 times OD, 0.5 times OOL; frons coriaceous-slightly rugose, vertex, temple and gena coriaceous, face coriaceous-transversally rugose; frons excavated, not delimited by sharp lateral margins; eye 1.6 times longer than wide; eye width 1.75 times longer than the temple in dorsal view; malar space 0.4 times eye height slightly shorter than the width of hypoclypeal depression; mandibles apparently bidentate; antennae broken.

Mesosoma: 1.4 times longer than high ( Fig. 8C ), and 1.5 times longer than wide; pronotal collar short but visible in dorsal view, pronotal lobe scrobiculate; mesoscutum slightly transverse in dorsal view, its median length 0.8 times its width; median mesoscutal lobe coriaceous with a median, scrobiculate longitudinal furrow; lateral mesoscutal lobes coriaceous; notauli wide deep and scrobiculate, not joining, finishing at the base of mesoscutom in longitudinal rugose area, prescutellar furrow with six transverse carinae; propodeum rugose-areolate, with two distinct diverging carinae, area between carinae smooth and polished; mesopleuron ventrally coriaceousrugose remaining area rugose; subalar sulcus scrobiculate; precoxal sulcus wide, deep, smooth, slightly scrobiculate running along two thirds of mesopleuron.

Wings: forewing 3.1 times longer than wide ( Fig. 8D ). Pterostigma 3.4 as long as wide and 0.7 times as long as R. Vein r as long as 3RSa, 0.3 times as long as 3RSb, and 1.3 times as long as r-m. Vein 2RS interstitial with m-cu, vein RS+Mb absent. Hind wing vein M + CU 0.6 times as long as 1 M, m-cu slightly curved towards wing apex.

Legs: fore tibia with a row of spines along anterior margin. Hind coxa with distinct basoventral tooth. Hind femur 2.5 times longer than wide.

Metasoma: first tergite, slightly longer than its apical width, coriaceous longitudinally rugose, with two longitudinal, subparallel carinae running along the entire length of tergite ( Fig. 8E ). Second tergite costate-coriaceous; third tergite costate-coriaceous on basal half, coriaceous apical in the half; suture between second and third tergite distinct and almost straight. Remaining tergites smooth and polished slightly coriaceous. Ovipositor about 4.9 mm, 2.2 times as long as metasoma.

Variation. Body color honey yellow to yellow. Body size 3.0– 3.7 mm. Antenna with 28 flagellomeres. Prescutellar furrow with six transverse carinae.

Male. Similar to female. Body size 2.7–3.4 mm ( Fig. 8F ). Antenna with 28 flagellomeres. Hind femur swollen, 2.5 times longer than wide.

Biology. Gahan (1921) mentioned that the type specimens of A. gallicola were reared from galls of a cynipid wasp in ‘ Quercus pinifolia ’; however, this species name is not valid. It is, therefore, possible that the valid name for the aforementioned species is Q. palustris Münchh , since this oak species is distributed in the eastern and central United States and its common name is pin oak, which probably led to the confusion in the original description.

Material Examined. HOLOTYPE ( NMNH): one female, Prince George, University of Maryland Campus , ML, 20-IV-1911, ex. galls on Quercus pinifolia, A.B. Gahan . PARATYPES (NMNH): two males, same data as Holotype except on collection dates, 27-IV-1911 and 19-V-1911. Other examined material (NMNH): two females, Stamford, CT, 27-VI-1930 and summer1931, ex. galls on Quercus palustris . One female, one male, Washington Co., AR, 4-VI-1965, ex. galls on Quercus rubra . One male, East Fall Church, VA, ex. galls of Callirhytis seminosa on Quercus rubra .

A list with the remaining examined specimens of Allorhogas from United States that are deposited in the NMNH and that do not belong to the species included in this study is shown in Supp Table S4 (online only).

Key to the species of Allorhogas associated with cynipid galls on species of Quercus in eastern United States. 1. Mesoscutum with a medial scrobiculate longitudinal furrow in its medial lobe, metanotum and the area surrounding scutellar disk honey yellow to brown; propedeum rugose-areolate, slightly coriaceous-rugulose or smooth and polished .............2

- Mesoscutum without medial longitudinal furrow in its medial lobe; metanotum and area surrounding scutellar disk dark brown to black; propodeum coriaceous-transversally rugulose ................. ...... Al. bassettia Samacá-Sáenz, Zaldívar-Riverón et Egan sp. nov.

2 (1). Body size 1.6–3.0 mm; propodeum rugose-areolate or slightly coriaceous-rugulose; ovipositor as long, or near as long as metasoma ........................................................................... 3

- Body size 3.0– 4.2 mm; propodeum smooth and polished; ovipositor considerably longer than metasoma, about twice its size ................................................................. A. gallicola Gahan

3 (2). Head, legs and metasoma honey yellow; prescutellar furrow with 4–5 transverse carinae; fifth tergite smooth slightly punctate or slightly costate ........................................................ 4

- Head, legs and metasoma whitish-yellow to whitish-brown; prescutellar furrow with 7–8 transverse carinae, fifth tergite smooth and polished .................................................................... Al. caulinarius Samacá-Sáenz, Zaldívar-Riverón et Egan sp. nov.

4 (3). Body size 2.2–2.5 mm; mesoscutal lobes coriaceus; propodeum smooth to slightly coriaceous-rugulose; fifth tergite slightly longitudinally costate...................................................................... Al. belonocnema Samacá-Sáenz, Zaldívar-Riverón et Egan sp. nov.

- Body size 1.6–1.9 mm; mesoscutal lobes acinose; propodeum entirely rugose-areolate; fifth tergite smooth slightly punctate............ ..... Al. gallifolia Samacá-Sáenz, Zaldívar-Riverón et Egan sp. nov.

Figures

Fig. 8. Allorhogas gallicola. Female, Holotype: (A) habitus, lateral, view; (B) head and mesosoma, dorsal view; (C) head and mesosoma, lateral view; (D) forewing; (E) metasoma, dorsal view. Male, Paratype: (F) habitus, lateral view.