Orasema violacea Ashmead

Baker, Austin J. & Heraty, John M., 2020, The New World ant parasitoid genus Orasema (Hymenoptera: Eucharitidae), Zootaxa 4888 (1), pp. 1-84 : 21-23

Orasema violacea Ashmead

urn:lsid:zoobank.org:act:B4A7D285-5759-413D-AF1D-97C8CD7E450C

( Figs 7B , 10 )

Orasema violacea Ashmead 1888: 187–188 .

Orasema violacea ; Gahan 1940: 445–446. Redescription and identification key.

Diagnosis. Distinguished from O. scaura by having five tarsomeres and the length of the flagellum as long as or longer than the height of the head, and from O. iridescens by having a shorter female petiole (PTL:PTW = 0.9–1.2 versus 2.1–3.0 in O. iridescens ), shorter/wider antenna (female F2L:F2W = 1.3–1.6 versus 2.0– 2.5 in O. iridescens ), and setose eyes ( Fig. 10B ).

This species is most similar to O. coloradensis , but is distinguished by more coarsely areolate sculpture on the mesoscutal midlobe compared to the costate sculpture in O. coloradensis and other members of the group ( Fig. 7 ). Orasema violacea also tends to have a larger body size than most, but not all, specimens of O. coloradensis .

Description. Female. Length 3.3–3.8 mm ( Fig. 10A ). Color. Head and mesosoma blue, green, or some com-bination. Scape, pedicel, anellus, and flagellum brown. Coxae iridescent blue-green; femora mostly brown with iridescence, tips pale; tibiae yellow. Gaster same as mesosoma or brown with iridescent reflections. Head ( Fig. 10B ). HW:HH = 1.1–1.2; face rugose-reticulate; eyes sparsely setose, IOD:EH = 1.5–1.6; MS:EH = 0.7–0.8; supraclypeal area as long as broad, equal to length of clypeus, weakly rugose. Labrum with 4 digits. Occiput with dorsal margin abrupt. Pedicel globose, as broad as F1. FL:HH = 1.0–1.2; F2L:F2W = 1.3–1.6, F2L:F3L = 1.3–1.5 ( Fig. 10D ). Mesosoma ( Fig. 10C, F ). ML:MH = 1.2–1.4. Mesoscutal midlobe rugose-areolate to areolate-reticulate, sparsely setose; lateral lobe rugose-reticulate. Axilla areolate-reticulate, dorsally rounded, on roughly same plane as mesoscutellum; scutoscutellar sulcus broad, irregularly foveate, and broadly separated from transscutal articulation; mesoscutellar disc areolate-reticulate; frenal line irregularly foveate; frenum areolate-reticulate; axillular sulcus distinct and foveate; axillula areolate-reticulate. Propodeal disc flat, rugose-areolate, without median carina ( Fig. 10G ); callus areolate-reticulate, densely setose. Propleuron reticulate. Prepectus areolate-reticulate. Mesepisternum, upper-, and lower mesepimeron reticulate; transepimeral sulcus weakly impressed. Metepisternum laterally reticulate. HCL:HCW = 1.5–1.8, reticulate; HFL:HFW = 4.4–4.8. FWL:FWW = 2.2–2.4, FWL:ML = 1.6–1.7; submarginal vein with several long setae; postmarginal vein slightly longer than stigmal vein. Metasoma. Petiole broad, linear in profile, PTL:PTW = 0.9–1.2, PTL:HCL = 0.7–0.8, areolate-reticulate, lateral margin with longitudinal carina continuous with basal flange, ventral sulcus absent. First (ventral) valvula with 6–8 small, narrowly separated teeth, second (dorsal) valvula with 8–10 annuli that are narrowly separated dorsally, the carinae coalescing.

Male. Length 2.8–3.1 mm. HW:HH = 1.1–1.3. Scape brown; FL:HH = 1.3; anellus disc-shaped; F2L:F2W = 1.3–1.5 ( Fig. 10E ). Femora mostly brown, tips pale; tibiae yellow. PTL:PTW = 1.7–2.3, PTL:HCL = 1.0–1.3.

Hosts. Unknown.

Plant associates. Unknown.

Distribution ( Fig. 5 ). United States: FL. Collected June–July.

Material examined. Holotype. UNITED STATES. Florida : Eastern Florida [♀, deposited in USNM: USN-MENT00809466, type images: http://n 2t.net/ark:/65665/3b0c20be4-0882-4c1b-ad6a-a0987be4f0ce] . Additional material examined. UNITED STATES. Florida: Franklin Co., St. George State Park , 29 ° 44’46”N, 84 ° 52’8”W, 13.vi.1980, L. Stange [1³, FSCA: UCRCENT00411767]. Levy Co., 29 ° 19’12”N, 82 ° 44’24”W, 22.vi.1957, H.V. Weems, Jr. [3³, FSCA: UCRCENT00411765, LACM: UCRCENT00305126, USNM: UCRCENT00248390]; 3.vii.1954 [2♀, USNM: UCRCENT00248392–93]; 3.vii.1958 [1♀, FSCA: UCRCENT00411754]; 7.vii.1955 [1♀, FSCA: UCRCENT00411756].

Discussion. Specimens of O. coloradensis from Florida show a large amount of morphological variation with some specimens quite similar overall to those of O. violacea , making the two species occasionally difficult to distinguish ( Fig. 7B ). This may indicate that O. violacea and O. coloradensis are conspecific or, if separate, that some introgression between the two may occur in Florida. Without molecular data for O. violacea to confirm or reject these hypotheses, it seems inappropriate at this time to synonymize these species. There is a specimen of O. coloradensis worth noting (USNM: UCRCENT00248391) that was collected by Ashmead from the O. violacea type locality, eastern Florida, but has no additional label information. The few specimens examined that were determined to be O. violacea were mostly collected in the 1950s with a single specimen collected in 1980. Multiple recent attempts failed to collect fresh specimens, which, given the context of the changing ant fauna in Florida (especially Solenopsis , one of the hosts for O. coloradensis ), may indicate extinction of the species.

Figures

FIGURE 5. Distribution map of species in the Orasema coloradensis species group.

FIGURE 7. Comparison of the dorsal mesosoma of female Orasema coloradensis and O. violacea. All specimens scaled proportionately. A, O. coloradensis Lectotype from Colorado (UCRCENT00238021); B, O. violacea holotype from Florida (USN- MENT00809466);C,O.coloradensisfromColorado(UCRCENT00444500);D,O.coloradensisfromTexas(UCRCENT00320732); E, O. coloradensis from Texas (UCRCENT00397223); F, O. coloradensis from Idaho (UCRCENT00352500); G, O. coloradensis from Maryland (UCRCENT00414400); H, O. coloradensis from Florida (UCRCENT00411745); I, O. coloradensis from Florida (UCRCENT00139590); J, O. coloradensis from Florida (UCRCENT00404257).

FIGURE 10. Orasema violacea. Female (UCRCENT00411756): A, habitus, lateral; B, head, anterior; C, mesosoma, lateral; D, antenna; F, mesosoma, dorsal; G, propodeum, posterior. Male (UCRCENT00248390): E, antenna.