Signiphora xanthographa Blanchard, 1936

Woolley, J. B. & Dal Molin, A., 2017, Taxonomic revision of the flavopalliata species group of Signiphora (Hymenoptera: Signiphoridae), Zootaxa 4315 (1), pp. 1-150 : 96-100

Signiphora xanthographa Blanchard, 1936

Figures 361–376

http://eol.org/pages/855928

Signiphora xanthographa Blanchard, 1936: 18 . Female, male.

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Diagnosis. Fore wing marginal vein with seta M1; sculpture on vertex, frons and mesoscutum reticulate to strongly reticulate; antennal clava very short (clava length:scape length 1.20–1.57) with a uniform pale brown color; Length Mt1:length Mt 2 in female usually 0.66 (0.50–0.66); male metasoma uniformly brown to apex. Males common. S. xanthographa is most similar to S. coquilletti , S. aleyrodis , and S. flavella . It is distinguished from S. coquilletti and S. aleyrodis by the reticulate sculpture, the short antennal clava (clava length:scape length for S. coquilletti females 1.52–1.82); and the male coloration. It is distinguished from S. flavella by the preceding attributes and by the medial emargination on the anterodorsal margin of Mt8 (the anterodorsal margin of Mt 8 in S. flavella is transverse and without a medial emargination).

Description. Female. Length, anterior margin of pronotum to epiproct apex, 0.43–0.76 mm (n=31). Head brown, somewhat lighter brown on frons. Antenna uniformly tan, antennal clava occasionally dusky at apex. Pronotum uniformly light brown to light brown in medial 2/3. Mesoscutum brown in anterior 1/2–5/6 and in medial 2/3, yellow to pale yellow in posterior 1/2–1/6 and laterally. Scutellum and metanotum pale yellow. Propodeum including medial sclerite pale yellow except light brown along posterior margins of each. Mt1 and anterior 1/2 of Mt2 light brown, Mt3–Mt4 dark brown, Mt5–Mt7 yellow or light brown, occasionally with Mt4– Mt7 yellow or with metasoma uniformly brown to apex. Ovipositor sheaths dusky. Legs pale yellow. Fore wing infuscated from base to slightly beyond distal end of stigma vein, with usual hyaline areas at wing base.

Head. Mandibular ducts enlarged apically. Pedicel length:scape length 0.52–0.78; 3 anelli, second anellus from 1.5–3.0× length of the first, third from 1.5–4.0× length of the first; clava length:scape length 1.20–1.57. Vertex and frons reticulate to strongly reticulate, frons with four longitudinal rows of minute punctations.

Mesosoma. Pronotum transversely reticulate to transversely imbricate. Mesoscutum reticulate to strongly reticulate, often transversely reticulate in anterior 1/3. Scutellum, metanotum and medial sclerite of propodeum weakly reticulate to transversely and weakly reticulate. Scutellum with 4 setae and 2 campaniform sensilla. Medial propodeal sclerite rounded, process on medial sclerite rounded or pointed apically. Fore wing length:width 2.8–3.5; fore wing LMS:fore wing width 1.1–1.7; marginal vein:stigmal vein 1.9–3.1; marginal vein with 6 dorsal setae and no ventral setae, rarely without seta M1; seta M3 length:marginal vein length 0.33–0.57; apical end of costal cell at seta M1–M2. Hind wing with subparallel margins, length:width 6.7–10.7; hind wing width:fore wing width 0.29– 0.47; LMS hind wing:hind wing width 2.5–4.5. Mesofemur with 1 long spine and 1 short spine in posteroapical margin, mesotibial spur with 3–5 teeth; mesotibial spur length:basitarsus length 0.63–1.13; basitarsus length:mesotibia length 0.39–0.50.

Metasoma. Mt1 strongly bilobed with medial portion transverse or rounded; Length Mt1:length Mt2 1.0–2.0; ovipositor with anterior-most portion lying under Mt2–Mt4; ovipositor length:metasoma length 0.42–0.96; ovipositor sheath length:ovipositor length 0.20–0.29; Ms3–Ms6 with anterior projections short to medium; Ms 6 in posterior 1/4 metasoma and with 8–10 setae; Mt8 with anterodorsal margin with a rounded medial emargination and with anterolateral margins transverse.

Male. Length, anterior margin of pronotum to epiproct apex, 0.40–0.65 mm (n=20). As described for female except the following: anterior 1/2–3/4 and medial 2/3 mesoscutum brown, scutellum to propodeum yellow to pale tan, medial sclerite of propodeum occasionally tan or pale brown. Metasoma uniformly brown to apex, occasionally with Mt6 and Mt7 lighter than preceding terga. Antennal clava length:scape length 1.2–1.8, mesotibial spur with 2–4 teeth; Ms8 a narrow transverse strip, without an anterior projection, extending past cerci laterally. Genitalia normal for the flavopalliata group, digitus length 2× its width, digitus with one short apical denticle and one seta at its midpoint.

Discussion. De Santis (1973) recognized the similarity between S. townsendi and S. xanthographa and he stated that with further study the latter might come to be regarded as a subspecies of the former. We believe S. townsend i and S. aleyrodis (q.v.) to represent the same species for the reasons given above, and have synonymized the former under the latter. The type specimens of S. xanthographa have the strongly reticulate sculpture on the vertex and mesoscutum characteristic of this species, but are somewhat unusual in that Mt5–Mt7 are concolorous with Mt1–Mt4. However, females with this metasomal coloration are common in the long series collected by DeBach and Rose in Brazil and Argentina. In some specimens in a series from Palmira, Valle de Cauca, Colombia (collected by Fred Bennett from Bemisia tabaci on Glycinis max, TAMU-ENTO X046246, X0616124, X0616129– 136, FSCA); the sculpture on the frontovertex and occasionally the mesoscutum is transversely imbricate, as in S. aleyrodis . In addition, the coloration of Mt4–Mt 6 in males is also somewhat lighter that the basal tergites, also characteristic of S. aleyrodis . We are treating these as S. xanthographa , but as discussed above under S. aleyrodis , it is quite possible that there are additional cryptic species involved that have this morphotype. Two specimens are known from Asia: TAMU-ENTO X0852767 (FSCA) coll. H.W. Browning ex: whitefly in Thailand (94-533-18); and UCRC ENT 299588, Hong Kong, New Territories, Bible Institute, coll. Cheng, 18-VII-1971, ex Aonidiella aurantii on Cycas revoluta , R71-55-c. The host record for the Hong Kong specimen is unusual for this species, but otherwise the specimen fits the diagnosis.

Type material. Signiphora xanthographa — LECTOTYPE ♀ [here designated]: Cotypus 688, INTA, ARGENTINA, [ENTRE RIOS], Parana, coll. Baez, V-1936, ex Aleurotrixus [sic] . PARALECTOTYPES: data as lectotype, 1 ♀ and 3 ♂, S. xanthographa was described by Blanchard (1936) from two ♀ and three ♂ specimens on one slide, No . 688 Cotypus, INTA. The ♀ to the lower right (slide oriented with the two labels bearing species name and type number to the right) is here designated lectotype and the slide has been labeled accordingly.

Other material examined. ARGENTINA: Buenos Aires: 3 mixed series. UCRC ENT 299563–299564, 299572 ( UCR) . ARGENTINA: Santa Fe: 1 sex unknown. BMNH (E) 990222 ( BMNH) . ARGENTINA: 2 sex unknown, 8 mixed series, 3 ♀, UCRC ENT 299560–299562, 299565–299571 , 299573–299575 ( UCR) . BRAZIL: Bahia: 3 ♀, USNM ENT 763119 –763121 (USNM). BRAZIL: Mato Grosso do Sul: 2 ♀, USNM ENT 763122 – 763123 (USNM). BRAZIL: Pernambuco: 2 ♂, 2 ♀, UCRC ENT 299533 –299536 (UCR). BRAZIL: Rio de Janeiro: 1 sex unknown, 21 mixed series, 2 ♀, UCRC ENT 299527–299532, 299539–299555 , 300236 ( UCR) . BRAZIL: Sao Paulo: 4 mixed series, 2 ♀, UCRC ENT 299537–299538, 299556–299559 ( UCR) . CHILE: 1 ♂, 7 ♀, BMNH (E) 991089, 991090 ( BMNH) ; TAMU-ENTO X0616373–X0616377, X0855988 (TAMU). CHINA: Hong Kong : 1 ♂, UCRC ENT 299508 ( UCR) . COLOMBIA: 3 ♂, 5 ♀, TAMU-ENTO X0460246, X0616124, X0616129, X0616130, X0616131, X0616132, X0616135, X0616136 ( FSCA) . PERU: 1 mixed series, 6 ♀, UCRC ENT 299509 –299515 (UCR). THAILAND: 1 ♀, TAMU-ENTO X0852767 ( FSCA) . TRINIDAD AND TOBAGO: 1 ♀, BMNH (E) 990221 ( BMNH) . URUGUAY: 4 ♂, 7 ♀: UCRC ENT 299516 –299526 (UCR); 20 pinned specimens: USNM ENT 763509–763528 (USNM).

Biology. This species is biparental and has been reared primarily from Aleyrodidae of the genera Aleurothrixus Quaintance and Baker, Aleyrodes , and Tetraleurodes Cockerell. Of the two records from Diaspididae , one was a mixed rearing-sample containing A. floccosus and L. gloverii and one was from C. aonidum . In his description, Blanchard (1936) stated that this species is an internal parasitoid of Aleurothrixus floccosus and A. howardi (Quaintance) . Slide-mounted host material from Argentina and Brazil collected by Rose and DeBach provides conclusive evidence that S. xanthographa is an external hyperparasitoid of Amitus spiniferus (Brèthes) (Platygastridae) pupae in A. floccosus . Rose observed the ovipositional behavior on A. floccosus in Argentina and in the UC-Riverside quarantine laboratory and noted that oviposition occurred only when females were provided with parasitized hosts (Rose, personal communication).

Figures

FIGURES 361 – 364. Signiphora xanthographa: 361, head (UCRC ENT 299525); 362, female antenna (TAMU-ENTO X 0616375); 363, mandibles (TAMU-ENTO X 0616375); 364, male antenna (UCRC ENT 299525).

FIGURES 365 – 370. Signiphora xanthographa: 365, fore wing, female (TAMU-ENTO X 0616375); 366, venation of fore wing (TAMU-ENTO X 0616375); 367, hind wing, female (TAMU-ENTO X 0616376); 368, venation of hind wing (TAMU-ENTO X 0616376); 369, middle leg, female (UCRC ENT 299525); 370, Mt 8 of metasoma, female (TAMU-ENTO X 0616377).

FIGURES 371 – 376. Signiphora xanthographa: 371, female habitus (TAMU-ENTO X 0616377); 372, mesosoma of female (BMNH (E) 99021); 373, metasoma of female (TAMU-ENTO X 0616377); 374, male habitus (TAMU-ENTO X 0616376); 375, male genitalia (TAMU-ENTO X 0616376); 376, Ms 8 of metasoma, male (TAMU-ENTO X 0616376).