Orasema texana Gahan

Baker, Austin J. & Heraty, John M., 2020, The New World ant parasitoid genus Orasema (Hymenoptera: Eucharitidae), Zootaxa 4888 (1), pp. 1-84 : 34-36

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Orasema texana Gahan


Orasema texana Gahan


( Fig. 16 View FIGURE 16 )

Orasema texana Gahan 1940: 440–441 .

Diagnosis. Distinguished from other members of the O. bakeri group by usually having a broad medial depression in the mesoscutal midlobe ( Fig. 16F View FIGURE 16 ), mesoscutal mid- and lateral lobes angulate at the notaulus anteriorly ( Fig. 16F View FIGURE 16 ), and a callar nib present ( Fig. 16G View FIGURE 16 ). Other combinations of features that help diagnose O. texana include: petiole short/wide (PTL:PTW = 0.6–1.0 in females; 1.6–3.2 in males), female scape yellow ( Fig. 16D View FIGURE 16 ), propodeum often with median longitudinal carina ( Fig. 16G View FIGURE 16 ), mesoscutal side lobes often with shallow depression dorsally ( Fig. 16F View FIGURE 16 ), and axillular sulcus poorly defined to absent ( Fig. 16C View FIGURE 16 ).

Description. Female. Length 2.5–3.4 mm ( Fig. 16A View FIGURE 16 ). Color. Head and mesosoma dark, iridescent blue-green. Scape, pedicle, and anellus yellow. Maxilla and labium brown. Tibiae yellow. Fore wing venation pale brown. Head ( Fig. 16B View FIGURE 16 ). Head in frontal view subquadrate; HW:HH =1.1–1.3; scrobal depression shallow, laterally rounded, reticulate; eyes bare, IOD:EH =1.5–2.0; MS:EH = 0.6–1.0; supraclypeal area broader than long, smooth; epistomal sulcus distinct but shallow; anteclypeus distinct, broadly rounded. Palpal formula 2:2. Occiput with dorsal margin abrupt. Pedicel globose, broader than F1. FL:HH = 0.9–1.1; F2L:F2W = 1.0–1.6, F2L:F3L = 1.2–1.8 ( Fig. 16D View FIGURE 16 ). Mesosoma ( Fig. 16C, F View FIGURE 16 ). ML:MH = 1.1–1.4. Mesoscutal midlobe bare; lateral lobe weakly reticulate to imbricate with an irregular dorsal impression; notauli deep. Axilla weakly rugose-reticulate, dorsally well above mesoscutel-lum; scutoscutellar sulcus broad, irregularly foveate, reaching transscutal articulation; mesoscutellar disc as long as broad, areolate-reticulate; frenal line irregularly foveate; axillular sulcus absent; axillula areolate-reticulate. Propodeal disc flat, with median carina ( Fig. 16G View FIGURE 16 ); callus smooth, bare; callar nib present. Propleuron nearly flat. Postpectal carina absent. Upper and lower mesepimeron smooth anteriorly, reticulate posteriorly; transepimeral sulcus weakly impressed. Metepisternum laterally smooth. HCL:HCW = 1.4–2.0; HFL:HFW = 3.7–5.9, evenly covered with short setae. FWL:FWW = 2.2–2.5, FWL:ML = 1.9–2.2; fore wing with basal third sparsely setose, including speculum and costal cell, wing disc setose; marginal fringe relatively long; submarginal vein bare; marginal vein with minute setae; stigmal vein about the same length as width, slightly angled toward wing apex; postmarginal vein longer than stigmal vein. Metasoma. Petiole cylindrical, linear in profile, PTL:PTW = 0.6–1.0, PTL:HCL = 0.4–0.6, reticulate, lateral margin with longitudinal carina continuous with basal flange, ventral sulcus absent. Ovipositor with subapical carina present; second (dorsal) valvula with 6 or 7 annuli that are narrowly separated dorsally, the carinae coalescing.

Male. Length 2.3–2.7 mm. HW:HH = 1.2–1.5; FL:HH = 1.1–1.3, F2L:F2W = 1.1–1.6 ( Fig. 16E View FIGURE 16 ). Tibiae yellow. PTL:PTW = 1.6–3.2, PTL:HCL = 0.8–1.4.

Planidium. Length 0.16 mm. Head with two pairs of dorsal cranial setae. Antenna, labial plates, and tergopleural line absent. Tergites I and II separate. Tergites I, II, and III with dorsal setae. Tergites II and VI with lateral setae. Tergites I, III, V, and VII with ventral setae. Tergites IV–VIII with posteriorly pointing ventral projections. Tergite IX with separated leaflike ventral plate. Caudal pad present; caudal cerci present, about as long as tergites XI+XII.

The planidium of O. texana has relatively short caudal cerci but no other obvious morphological features to differentiate it from other Orasema species, and it closely resembles illustrations of other species, like O. viridis ( Johnson et al. 1986, fig. 2).

Hosts. Unknown.

Plant associates. Observed ovipositing into huisatch ( Fabaceae : Vachellia farnesiana (L.) Wight et Arn.) in Texas. Swept from Chilopsis linearis ( Bignoniaceae ) and Vachellia vernicosa (Britton & Rose) Seigler & Ebinger in Arizona, Chilopsis linearis in California, and Vachellia constricta (Benth.) Seigler & Ebinger in New Mexico.

Distribution ( Fig. 11 View FIGURE 11 ) Mexico: BC, BS, HG, NA, OA, SI, TM; United States: AZ, CA, NM, TX. Collected March–November.

Material Examined. Holotype. UNITED STATES. Texas: Grayson Co., Denison, 33 ° 45’0”N, 96 ° 31’48”W, 26.viii.1937, Christenson & Jones, sweep, C-3511 [♀, deposited in USNM: USNMENT1520795, type images: http://n 2t.net/ark:/65665/3f8507c59-e9c9-4b8e-9bc7-6d9b34e9b034]. Larval slides. UNITED STATES. Texas: San Patricio Co. , Welder Wildlife Ref. near Vena Mills , 3m, 28 ° 06’42”N, 97 ° 24’24”W, 26.vi.1989, J. Heraty, Aster [5?, UCRC: UCRCENT00513224–28] GoogleMaps GoogleMaps . Additional material examined. 265 specimens, see supplementary material. GenBank sequences. UCRCENT00292561 (D3212): 18S ( MH 231711 View Materials ) , 28S D2 ( MH 247394 View Materials ) , 28S D3–5 ( MH 247546 View Materials ) , COI-NJ ( MH 247760 View Materials ) ; UCRCENT00412495 (D3929): 18S ( KR632475.1 ) , 28S D2 ( KR632406.1 ) , 28S D3–5 ( KR632445.1 ) , COI-BC ( KR733127.1 ) .


Naturhistorisches Museum, Basel














Orasema texana Gahan

Baker, Austin J. & Heraty, John M. 2020

Orasema texana

Gahan, A. B. 1940: 441