Acanthocaudus bicolor Kula

Kula, Robert R., Johnson, Paul J., Heidel-Baker, Thelma T. & Boe, Arvid, 2017, A new species of Acanthocaudus Smith (Braconidae: Aphidiinae), with a key to species and new host and distribution records for aphidiines associated with Silphium perfoliatum L. (Asterales: Asteraceae), Zootaxa 4236 (3), pp. 543-552 : 546-548

Acanthocaudus bicolor Kula , new species

( Fig. 1 )

Diagnosis. The mesosoma is yellow except the mesonotum is brown in A. bicolor ; it is entirely yellow in A. caudacanthus . The head is yellow with the ocellar triangle entirely brown to black or yellow with brown to black markings around the periphery of each ocellus in A. bicolor ; it is entirely brown or brown dorsally and gradually transitioning to yellow ventrally in A. tissoti .

Description. Female. Body length: 1.93–2.15 mm. Head: HL 0.65–0.70X HW, HW 1.00–1.03X TW, FW 1.38–1.70X FH, EL 0.67–0.80X EH, EH 3.00–4.86X MSH, F1L 3.33–4.20X F1W, F2L 2.75–3.14X F2W, PFL 2.22–3.17X PFW, F1L 0.92–1.14X F2L, F2L 1.09–1.16X PFL; antenna with 10 flagellomeres, maxillary palpus with 4 palpomeres, labial palpus with 2 palpomeres; face smooth, setiferous; frons smooth, glabrous; gena and vertex smooth, setiferous; occiput smooth, glabrous; eye and clypeus setiferous; mandible with two teeth, setiferous.

Mesosoma: ML 1.73–1.82X MW, ML 1.32–1.41X MH, MW 0.72–0.79X MH, pronotal collar anteriorly with smooth setiferous trapezoidal area that narrows anteriorly to posteriorly, pronotal collar posteriorly with smooth glabrous depressed rectangular area (sometimes divided into two shallow oblong depressions), anterior portion of pronotal collar setiferous, lateral portion of pronotum separated from collar by carina, smooth, glabrous except setiferous along margins; notauli present anteriorly, with a few crenulae; mesoscutum (excluding notauli) smooth, setiferous laterally, anteriorly, and where notauli would extend on disc of mesoscutum; scutellar sulcus smooth; scutellar disc smooth, setiferous peripherally; propodeum with rugose to smooth pentagonal areola, with median carina anteriad areola ranging from discrete to represented by weak rugosities, with transverse carina mesally emanating laterally from areola and extending to metapleural carina, setiferous; epicnemial carina present; precoxal sulcus absent; posterior mesopleural furrow smooth; reminder of mesopleuron smooth, with a few setae peripherally but otherwise glabrous; metapleuron smooth, setiferous.

Forewing: SL 2.39–2.62X SH; hyaline; C+Sc+R, 1M, and R1 tubular; r&RS tubular and extending on wing disc approximately to distance where R1 ends; 1A tubular proximally transitioning to spectral distally; M+CU nebulous or spectral except minutely tubular where it meets 1M; 1CU spectral except minutely tubular where it meets 1M; all other veins spectral or absent.

Hind wing: Hyaline; C+Sc+R, Sc+R, R1 tubular; all other veins spectral or absent.

Metasoma: T1L 2.10–2.50X T1aW, T1aW 0.90–1.00X T1bW; t1 smooth, setiferous laterally near primary and secondary tubercles; t2–t5 smooth, setiferous, setae located in posterior half of terga and in single line on each tergum, setae increasingly stout in posterior terga; t6–t7 smooth, with spines located in single line in posterior half of each tergum; t8 smooth, setiferous but setae stout as in t5; hypopygial prongs arcuate apically, setiferous ventrally and apically; accessory prongs present at base of hypopygial prongs, each with two setae at terminus; ovipositor sheaths down-curved, setiferous.

Color: Head (excluding antenna) either yellow with ocellar triangle entirely brown to black (50%) or yellow with brown to black markings around periphery of each ocellus (50%), scape yellow, pedicel yellowish brown, flagellomeres brown, mandible yellow except teeth brownish, palpi yellow; mesosoma yellow except mesonotum brown, forewing stigma and wing veins brown, legs yellow; t1 yellow, t2–t4 brown, t5–t8 yellow.

Male. As in female except: Head: HL 0.63–0.65X HW, HW 1.02–1.06X TW, FW 1.75X FH, EL 0.80–0.85X EH, F1L 2.50–2.88X F1W, F2L 2.50–2.57X F2W, F1L 1.11–1.15X F2L, frons with two setae.

Mesosoma: ML 1.78–1.83X MW.

Metasoma: t2–t8 setiferous, setae located in posterior half of terga and in single line on each tergum; apical metasomal sternum without prongs.

Color: Head (excluding antenna) brown, scape and pedicel yellowish brown, flagellomeres brown; mesosoma with mesonotum brown and remainder brownish yellow to yellowish brown; t1–t8 yellow.

Hosts. Uroleucon bradburyi (Olive) ex Aster sp.; undetermined aphids ex Symphiotrichum sp.

Material examined. Holotype female (white; typewritten) = USA, “ INDIANA: Tippecanoe Co. [;] Lily Wildlife Area [;] 40°23'15.26"N, 86°56'11.30"W [;] 3.x.2006 T.T. Heidel [;] ex aphids on Symphiotrichum sp. [;] 06-745.” Second label (red; partially handwritten, partially typewritten) = “ HOLOTYPE [;] Acanthocaudus [;] bicolor [;] Kula, 2017” ( USNM) . Paratypes: All INDIANA: Tippecanoe Co.; 2 ♀ 1 ♂ same data as holotype except ex Uroleucon bradburyi (Olive) on Aster sp., 06-701 ; 1 ♀ 1 ♂ Prophetstown State Park , 40°29'50.81"N 86°50'30.55"W, 9.vii.2007, T.T. Heidel, ex undet. aphids on Symphiotrichum sp., 07-383 (1 ♀ 1 ♂ PURC, 2 ♀ 1 ♂ USNM) .

Etymology. The specific epithet is Latin and refers to the color of the mesosoma in females, with mesonotum brown and rest of the mesosoma yellow.

Figures

FIGURE 1. Lateral habitus, Acanthocaudus bicolor Kula, new species, based on type series.