Syrphophagus wayanadensis Hayat

Hayat, Mohammad, 2012, On some Encyrtidae (Hymenoptera: Chalcidoidea) associated with gall-inducing psylloids, Phacopteron and Trioza species (Hemiptera: Phacopteronidae, Triozidae) in southern India, Zootaxa 3566, pp. 14-22 : 17-20

Syrphophagus wayanadensis Hayat , sp. nov.

( Figs 8–14 )

Female. Holotype. Length, 1.92 mm. Body black; frontovertex bluish up to anterior ocellus, purple anterior to ocelli; antennal scrobes with a slight greenish lustre. Mandible black. Antenna with radicle, and base and dorsal margin of scape dark brown, scape otherwise brownish yellow; pedicel brown in about basal half, yellow distally; funicle and basal two segments of clava pale brownish yellow to yellow, third segment of clava brown. Mesoscutum with some bronzy lustre; scutellum purple with sides bluish; tegula black. Wings hyaline. Legs with coxae, trochanters and femora black except apices of femora yellowish or brownish yellow; fore tibia brownish yellow with a black streak in dorsal half basally; mid tibia with basal half black, apical half white; hind tibia black in basal third, brownish yellow in distal two-thirds; fore and hind tarsi brownish yellow, mid tarsus and mid tibial spur whitish. Gaster largely with purple lustre, TI bluish; ovipositor sheaths (=third valvulae) black except brownish yellow apically.

Head. Occipital margin sharp; frontovertex width 0.26× head width; ocellar triangle with dorsal angle acute; posterior ocellus touching eye margin; POL 1.6× as long as OCL; head, in frontal view, about as wide as high; scrobes inverted U-shaped, moderately deep, with rounded margins; torulus with dorsal margin slightly below level of ventral eye margins and ventral margin separated from mouth margin by a distance less than own height (8:5.5); eye height 2× malar space; frontovertex with raised reticulate sculpture, the cells small, and with four rows of setigerous punctures (including a row along each eye margin); malar space with fine, elongate reticulate sculpture, except lineolate reticulate posterior to malar sulcus; setae on head brown; eyes bare. Mandible ( Fig. 9 ) with two teeth and a small truncation, lower tooth separated from middle tooth by a deep V-shaped incision. Antenna with scape 3.78× as long as broad and 3× as long as pedicel; F1 as long as pedicel, and slightly longer than F2 (6:5); F2–4 of same length and slightly shorter than F5; F6 as long as F1; funicle segments gradually increasing in width distally, F1 about 3×, and F6 1.26× as long as broad; clava shorter than F4–6 combined (15:16.75). (In paratype ( Fig. 8 ): pedicel slightly longer than F1; F1 2.66× as long as broad; relative lengths and widths of other segments similar to holotype). Relative measurements —head dorsal width, 53; frontovertex width, 14; head frontal height, 52; eye height, 34; malar space, 17; antennal scape length, 18; scape width, 4.75.

FIG URES 15–20. Last tergite of gaster: 15, Psyllaephagus phacopteron S. Singh , female, large specimen from Kerala; 16, female, examined paratype; 17, male, Kerala specimen; 18, P. garuga S. Singh , female. Last sternite of male gaster; 19, P. garuga , Kerala specimen; 20, P. phacopteron , Kerala specimen. Figures 15–18 of same scale, and 19 and 20 of same scale.

Mesosoma 1.16× as long as metasoma (71:61); mesoscutum 1.2× as long as scutellum (36:30); scutellum slightly longer than wide (30:28); mesoscutum with slightly raised reticulate sculpture, the cells transversely elongate; scutellum with sculpture deeper than on mesoscutum and elongate reticulate on sides; setae brown, scutellum with apical 2 or 3 pairs of setae long and recurved; sides of propodeum with silvery white setae; metapleuron with silvery white setae. Fore wing 2.46× as long as broad; venation extending to half wing length; marginal vein distinctly longer than postmarginal and stigmal veins (ratios, 1.0:0.55:0.73); ventral surface of costal cell with 2–3 lines of setae in proximal half, and a single line of setae in distal half; linea calva open posteriorly; venation and setation as in Fig. 10 . Relative measurements (paratype slide)—mid tibia length, 72; mid basitarsus length, 23; mid tibial spur length, 24.

Metasoma. Gaster apically pointed; TVII elongate-triangular, on slide, V-shaped; exserted part of ovipositor 0.11× gaster length; ovipositor and hypopygium as in Figs 11 and 12 . Relative measurements (paratype slide)—TVII length, 68; ovipositor length, 98; third valvula length, 30.

Male. Length, 1.89 mm. Similar in colour and sculpture to female, except for head dimensions, antenna and genitalia. Frontovertex width 0.43× head width; head, in frontal view, 1.08× as broad as high; torulus with ventral margin slightly below level of ventral eye margin and separated from mouth margin by 1.6× own height. Antenna ( Fig. 14 ) with scape 2.74× as long as broad; pedicel subtriangular, about as long as broad; funicle segments all longer than broad; F1 slightly longer than F2; funicle segments with numerous setae, the longer setae clearly longer than width of a segment; clava unsegmented, as long as distal half of F5 and F6 combined. Genitalia with distinct parameres ( Fig. 13 ); phallobase 0.68× mid tibia length; digitus short, with a denticle.

Material examined. Holotype ( NPC, Registration No. 136/13/124/2), female (on card), labelled “ INDIA: KERALA: Wayanad, Pookode, 16.xi.2011, Coll. U.A. Saleem” and “ Trioza jambolanae on Syzygium caryophyllatum ”.

Paratypes. 1 female (on slide under 5 coverslips, slide No. EH.1448), 2 males (one on card with right flagellum and left antenna beyond F4 missing; second male on slide under 6 coverslips, slide No. EH.1449), data same as for holotype. ( ZDAMU, Registration No. HYM. CH.658).

Host. Trioza jambolanae Crawford ( Hemiptera : Triozidae ) ( Fig. 24 ) from leaf galls of Syzygium caryophyllatum (L.) ( Figs 21, 22 ).

Distribution. India: Kerala.

Comments. The species of Syrphophagus are usually parasitoids or hyperparasitoids of Syrphidae (Diptera) and Aphidoidea ( Hemiptera ), but seven species are recorded as hyperparasitoids of Psylloidea. These are S. cassatus (Annecke) , S. elaeagni (Trjapitzin) , S. kovalevi (Trjapitzin) , S. mamitus Walker , S. similis (Prinsloo) , S. taeniatus (Förster) , and S. taiwanus Hayat & Lin.

This new species is placed in Syrphophagus because of the sharp occipital margin, generally similar type of fore wing venation, and the mesopleuron being clearly separated from the base of gaster by the metapleuron and hind coxa. Although there are species in Syrphophagus that are primary or secondary parasitoids of psylloids (see Noyes, 2012), S. wayanadensis is quite different from all other described species of the genus, including the seven species listed above, by the following combination of characters: frontovertex width about one quarter head width; mandible with the ventral tooth separated from the middle tooth by a deep V-shaped incision; funicle segments all longer than broad; F1 as long as pedicel and 2.66–3.0× as long as broad; F6 1.26× as long as broad; and clava shorter than F4–6 combined.

I compared this species will all available descriptions and figures of described Syrphophagus (e.g., De Santis 1964; Hoffer 1970a, 1970b; Prinsloo 1981; Hayat & Lin 1988; Trjapitzin 1989), and none appear to have the combination of characters given above.

Both O. alrake and S. wayanadensis have mandibles with a similar type of dentition (Figs 2, 9). I am unable to explain this in species of two distinct genera, but some functional reason of parasitizing the same host might be an explanation.

Etymology. The species name is based upon the name of the district Wayanad of Kerala State.

Figures

FIGURES 8 – 14. Syrphophagus wayanadensis Hayat, sp. nov. Female: 8, antenna; 9, mandibles; 10, basal part of fore wing; 11, ovipositor; 12, hypopygium. Male: 13, distal part of genitalia; 14, antenna.

FIGURES 21 – 25. Psylloid galls: 21, Syzygium caryophyllatum leaf with galls; 22, S. caryophyllatum, galls cut open to show developing psylloids; 23, S. cumini leaf galls; 24, Trioza jambolanae Crawford, adult; 25, Garuga pinnata, leaf galls. (Photographs by M. Nasser)