Signiphora coquilletti Ashmead, 1900

Woolley, J. B. & Dal Molin, A., 2017, Taxonomic revision of the flavopalliata species group of Signiphora (Hymenoptera: Signiphoridae), Zootaxa 4315 (1), pp. 1-150 : 33-36

Signiphora coquilletti Ashmead, 1900

Figures 93–108

http://eol.org/pages/855961

Signiphora coquilletti Ashmead, 1900: 412 . Female. urn:lsid:zoobank.org:act:308069C3-C2A6-4899-849B-17568C1DA68F Thysanus coquilletti: Peck (1951) .

Signiphora coquilletti: Rozanov (1965) .

Diagnosis. Fore wing marginal vein with seta M1; scutellum with 4 setae; antennal clava uniformly tan or light brown; Mt8 with anterodorsal margin with a rounded medial incision; Mt1 length:Mt2 length generally 0.50.

This species is very similar to S. aleyrodis and the two species are difficult to differentiate on the basis of structural characters or coloration. Unique biological traits of S. coquilletti are summarized below. This species is known to occur in California and Baja California, whereas S. aleyrodis has been collected from the remainder of Mexico, the West Indies, and the southeastern USA. Signiphora coquilletti is uniparental (males are very rare); whereas S. aleyrodis is biparental (males are common). The short Mt1 of S. coquilletti (Mt1 length:Mt2 length typically 0.50) is characteristic; although specimens of S. aleyrodis with Mt1:Mt 2 in this range have been observed they typically have a longer Mt2 (Mt1:Mt2 = 1.00). The antennal clava of S. coquilletti is slightly longer than that of S. aleyrodis , the ratio of clava length to scape length is from 1.52–1.82 in female S. coquilletti and 1.15–1.75 in female S. aleyrodis .

Description. Female. Length, anterior margin of pronotum to epiproct apex, 0.46–0.70 mm (n=19). Vertex and frons orange–brown, gena pale yellow. Antenna pale tan to brown. Pronotum brown or yellow in lateral 1/8–1/ 6 of its width. Mesoscutum brown in anterior 1/3–3/4, the posterior 2/3–1/4 and the remainder of mesosoma pale yellow to orange-yellow. Mt1 yellow or brown in posterior 1/2. Mt2–Mt4 brown to dark brown, occasionally Mt4 lighter brown. Mt5 and Mt6 yellow to orange yellow, rarely light brown. Mt7 yellow, orange/yellow, or dusky brown in medial and posterior 1/2. Mt8, epiproct, ovipositor sheaths, and often the apical 1/4 of lateral plates of ovipositor dusky brown. Fore wing infuscated from wing base to distal end stigmal vein with the normal hyaline areas in the basal area.

Head. Mandibular ducts enlarged apically; pedicel length:scape length 0.64–0.77; 3 anelli, second anellus 1.5– 2.0× the length of first, third anellus 2–4× the length of first; clava length:scape length 1.52–1.82; vertex and frons transversely striate with 4 longitudinal rows of minute punctations.

Mesosoma. Pronotum and mesoscutum transversely imbricate; scutellum, metanotum and medial sclerite of propodeum weakly imbricate. Scutellum with 4 medial setae and 2 campaniform sensilla; medial propodeal sclerite rounded, process on medial sclerite rounded or pointed apically. Fore wing length:width 2.9–3.7, fore wing LMS:width 1.3–1.6; marginal vein length:stigmal vein length 2.2–3.3; marginal vein with 6 dorsal setae and without ventral setae; seta M3 length:marginal vein length 0.45–0.64; apical end of costal cell at seta M1–M2. Hind wing with subparallel margins, its length:width 6.2–9.2; hind wing width:fore wing width 0.36–0.47; hind wing LMS:hind wing width 2.29–3.75. Mesofemur with 1 long spine and 1 short spine in posteroapical margin; mesotibial spur with 5–7 teeth (occasionally 4); mesotibial spur length:basitarsus length 0.83–1.00; basitarsus length:mesotibia length 0.56–0.68.

Metasoma. Mt1 bilobed with medial portion transverse, Mt1 length:Mt2 length 0.5–1.0, (see discussion); ovipositor with anterior-most portion lying under propodeum–Mt4; ovipositor length:metasoma length 0.55–0.84; ovipositor sheath length:ovipositor length 0.25–0.28; Ms3–Ms6 with anterior projections medium to long; Ms 6 in posterior 1/4 metasoma and with 7 or 8 setae; Mt8 with anterodorsal margin with a rounded or v-shaped medial emargination; Mt8 with margins lateral to medial emargination slightly convex, occasionally with lateral ends produced forward.

Male. Length, anterior margin of pronotum to epiproct apex, 0.43–0.52 mm (n=6). As described for female except: metasoma with apex yellow or orange/yellow, not dusky brown as in females, Mt1 bilobed with medial portion transverse or occasionally rounded, Mt1 length:Mt2 length 0.25–0.50 (see discussion); fore wing marginal vein rarely without seta M1; hind wing length:width 7.2–10.7; hind wing LMS:hind wing width 3.00–4.33. Genitalia normal for flavopalliata group, digitus with one apical denticle and one seta at its midpoint; digitus length approximately twice its width; MS8 a transverse strip, extending to cerci laterally.

Type material. HOLOTYPE ♀ [examined]: in balsam, USNM Type 4857, coll. 4-X-1887, ex Aleurodes [sic, likely Aleyrodes ] on Quercus agrifolia . Girault (1913) stated concerning this specimen: "probably reared in California by Coquillett (judging from the name, label, slide, and date).", and gave the type locality as "California (originally San Gabriel?)".

Other material examined. MEXICO: Baja California Norte: 16 ♀, UCRC ENT 299252, 299259 , 299297– 299310 ( UCR) . MEXICO: Baja California Sur: 1 ♂, 4 ♀, UCRC ENT 299253–299255, 299312–299313 ( UCR) . MEXICO: Morelos: 1 ♀, USNM ENT 763018 ( USNM) . MEXICO: Querétaro: 1 ♀, UCRC ENT 299256 ( UCR) . USA: California: 4 ♂, 72 ♀ UCRC ENT 299216–299219, 299221–299251 , 299257–299258, 299260– 299268, 299270–299296 ( UCR) ; INHS 72.514 (INHS); TAMU-ENTO X0460292, X0460293 (TAMU); USNM ENT 763014, 763020 (USNM); 1 host material UCRC ENT 299220. USA: Delaware: 2 ♀, USNM ENT 763019, 763021 ( USNM) . USA: Florida: 15 ♀, UCRC ENT 299311, 299314–299325 ( UCR) ; USNM ENT 763015– 763016 (USNM). USA: Texas: 9 ♀, TAMU-ENTO X0460294–X0460302 ( TAMU) . Country not specified: 1 ♀, UCRC ENT 299269 ( UCR) .

Discussion. Although the range of the Mt1: Mt2 ratio is 0.5–1.0 in females and 0.33–1.0 in males, in the great majority of specimens examined the ratio is 0.50 in both sexes. A series collected by M. Rose at Loreto, Baja California Sur, (XI-1971, ex:? Tetraleurodes mori (Quaintance) on Mexican guava, 3 ♀ in Hoyer's) appears also to be S. coquilletti but is very close to S. aleyrodis .

Biology. Signiphora coquilletti is a uniparental hyperparasitoid of a variety of whitefly through Encarsia Förster spp. and Eretmocerus spp. ( Aphelinidae ) and through Amitus spp. ( Platygastridae ). The few recorded rearings from armored scale are probably erroneous. Woolley & Vet (1981) observed that females of S. coquilletti would not oviposit in whitefly pupae unless the hosts contained prepupae or pupae of primary parasitoids. These authors described the unusual oviposition behavior of this species, in which the female deposits a fine silk-like web over the host whitefly pupa after oviposition. This behavior is not known to occur in other Signiphora spp. Males are very infrequently collected and unmated female S. coquilletti are capable of producing viable female progeny. However, JBW observed that males collected in the Riverside area readily mated with females in the laboratory. Copulation occurred after a brief courtship during which the males mounted the females and antennated the females' antennae and vertex. Following copulation, several mated females were dissected in saline, and active sperm were observed in the spermatheca.

Figures

FIGURES 93 – 96. Signiphora coquilletti: 93, head (UCR 299253); 94, female antenna (UCR 299253); 95, mandibles (UCR 299253); 96, male antenna (UCR 299228).

FIGURES 97 – 102. Signiphora coquilletti: 97, fore wing, female (UCR 299293); 98, venation of fore wing (UCR 299293); 99, hind wing, female (UCR 299293); 100, venation of hind wing (UCRC ENT 299293); 101, middle leg, female (UCR 299315); 102, Mt 8 of metasoma, female (TAMU-ENTO 0460295).

FIGURES 103 – 108. Signiphora coquilletti: 103, female habitus (URC 299230); 104, mesosoma of female (TAMU-ENTO X 0460297); 105, metasoma of female (TAMU-ENTO X 0460297); 106, male habitus (UCR 299228); 107, male genitalia (UCR 299228); 108, Ms 8 of metasoma, male (UCRC ENT 299228).