Isocolus freidbergi Melika, 2008

Karimpour, Y., Tavakoli, M. & Melika, G., 2008, New species of herb gallwasps from the Middle East (Hymenoptera, Cynipidae, Aylacini), Zootaxa 1854 (1), pp. 16-32 : 23-24

Isocolus freidbergi Melika , new species

( Figs 3a–j )

Etymology. The species is named in honour of Dr. Amnon Freidberg, Tel Aviv University, specialist in tephritid flies, collector of the species.

Type material. HOLOTYPE female: Israel, Qiryat Gat , 28.IV.1987. A. Freidberg, ex flower head Centaurea verutum . PARATYPES: 1 female and 2 males with the same labels as the holotype. The holotype female and one male paratype are deposited in HNHM ; 1 female and 1 male paratypes in SPL.

Diagnosis. Isocolus freidbergi n. sp. belongs to the group of Isocolus species in which the female antenna has 11 flagellomeres, metasomal tergite 2 without a latero-basal plate or even patch of white dense setae, tergite 2 at least in the 1/2–1/3 posterior part with uniform dense micropunctures; the mesoscutum with very strong transverse rugae; the median mesoscutal line is absent or very indistinct, in a form of a very short triangle. Most similar to I. cirsii Diakontschuk , however, differs in the presence of the areolet in the forewing, the radial cell can be partially obsoletely closed, 3.0–3.2 times as long as broad, the metapleural sulcus reaching the mesopleuron slightly higher than the half of its height, while in I. cirsii the radial cell only 2.9–3.0 times as long as broad; R1 and Rs do not reaching the wing margin, R1 straight; the areolet is very indistinct or even absent, the metapleural sulcus reaching the mesopleuron in the anterior 1/3 of its height.

Description. FEMALE (holotype). Head dark brown, mesosoma dark brown to black; metasoma reddish brown, lighter than head and mesosoma; antennae, except dark brown to black scape and pedicel, much lighter, brown. Legs lighter; coxae, trochanter and basal 2/3 of femora dark brown; proximal 1/3 of femora, tibiae and tarsi light brown.

Head ( Figs 3a–b ) 1.3 times as broad as high in front view, slightly broader than mesosoma, 2.1 times as long as broad from above; gena very slightly broadened behind eye in dorsal view; POL 1.2 times as long as OOL and 2.2 times as long as LOL; LOL 2.0 times as long as length of lateral ocellus; frontal ocellus with small impression toward frons; vertex, interocellar area, occiput alutaceous; postocciput and postgena finely coriaceous, with more dense white setae as in front; lower face and genae more densely pubescent as frons and vertex; area between antennal socket and eye with stronger coriaceous sculpture; transfacial distance 1.7 times as long as height of eye, 1.6 times as long as height of lower face (measuring from antennal rims to tip of clypeus), and 3.4 times as large as distance between antennal toruli and inner margin of eye; diameter of antennal torulus 1.75 times as large as distance between antennal toruli. Lower face laterally of finely coriaceous elevated central area with fine irradiating striae, extending into area between antennal rim and eye. Malar space finely coriaceous, 0.9 times as long as height of eye, with very fine delicate interrupted striae, reaching to eye margin. Clypeus shiny, very delicately coriaceous to smooth, slightly higher than broad, slightly impressed, rounded ventrally; anterior tentorial pits very indistinct; epistomal sulcus distinct, broad; clypeo-pleurostomal line indistinct. POL 1.6 times as short as malar space and 1.7 times as short as height of eye in front view. Mandibles light brown. Antenna with 11 flagellomeres, pedicel 1.4 times as short as F1, F1 equal or very slightly shorter than F2; F10 shortest flagellomere; F11 nearly as long as F8+F9; placodeal sensilla from F2, absent on F1 ( Fig. 3c ).

Mesosoma dark brown to black, 1.2 times as long as high in lateral view. Pronotum dorsomedially 1.50 (in holotype) – 1.65 times as short as greatest length measuring on outer margin; submedian pronotal pits distinct, narrow, transverse and deep, separated by carina which nearly twice narrower than width of submedian pit; carina of pronotal plate visible in very anterior part, just behind pit ( Fig. 3e ); pronotum with dense white setae along anterior edge, less setae laterally and few sparse short white setae dorsomedially; dorsomedially alutaceous, laterally uniformly coriaceous, along anteroventral edge with few short strong parallel rugae. Propleuron, dark brown, coriaceous, with wrinkles orientated mainly transversely. Mesoscutum ( Fig. 3f ) dark brown to black, with very few sparse short scattered setae, especially laterally to notauli; 1.25–1.30 times as broad as long in dorsal view. Notauli distinctly impressed, complete, reaching pronotum, uniformly broad prolong entire length, not broadened posteriorly, bottom with some transverse carinae; anterior parallel lines in anterior 1/3 of mesoscutum, very thin, indistinct, smooth, shiny; parapsidal lines distinct, smooth, shiny, extending to 2/3 of mesoscutum; median mesoscutal line absent; internotauli area and area between notaulus and parapsidal line with strong interrupted transverse striae, especially in posterior 2/3 of mesoscutum, becoming more delicate in anterior 1/3, on level of anterior parallel lines; area between transverse rugae very delicately coriaceous, mat, distance between transverse rugae at least twice longer than width of rugae; area between parapsidal line and lateral edge of mesoscutum finely transversely striate; lateral edge of mesoscutum emarginated. Mesoscutellum ( Fig. 3f ) only 1.1 times as broad as long in dorsal view; uniformly very dull rugose, area between rugae smooth, shiny, scutellar foveae in anterior 1/3 separated by very narrow carina; scutellar fovea subquadrate, only very slightly longer than broad, bottom of foveae semi-shiny, mat; scutellar foveae extended backwards slightly less than to half of mesoscutellum length. Dorso-axillar area dull rugose, with more longitudinally orientated strong rugae. Mesopleuron transversely striate, more delicately in lateroventral part; with very few short white setae, especially along ventral edge; acetabular carina delimiting a narrow area laterally; speculum impressed; mesopleural triangle mat, also minutely striate. Metapleural sulcus reaching mesopleuron slightly higher than half of its height; upper metapleural area (between metapleural sulcus and propodeal spiracle) dull rugose; metanotum with strong impression between metanotal trough and attachment point of hindwing, separated by dull rugose elevated area from another strong impression, located above propodeal spiracle; axillula finely coriaceous, with very few sparse short white setae ( Fig. 3g ). Propodeum dark brown to black, laterally finely coriaceous, with relatively sparse white long setae, not hidding the sculpture of propodeum; lateral propodeal carinae distinct, uniformly thick and subparallel in anterior 2/3, posteriorly diverging into two thinner carinae, which slightly curved outwards, especially outer one; central propodeal area mat, with some delicate wrinkles, without setae; ventral impressed area of metascutellum mat, delicately coriaceous, triangular, occupying 2/3 of metascutellum dorsomedially, metascutellum delicately coriaceous; metanotal trough smooth, mat, with white relatively sparse setae; propodeal spiracle transverse, with strong raised carina along anterior border; nucha dark brown with strong longitudinal parallel ridges ( Fig. 3h ). Forewing with very short cilia on margin; R1 not reaching wing margin, very slightly broadened in proximal third; radial cell opened or partially closed; Rs (in holotype) reaching margin of wing, partially closed radial cell or not reaching wing margin (in some paratypes); radial cell 3.0–3.2 times as long as broad; areolet triangular, distinct; Cu 1b curved outward wing margin ( Fig. 3i ). Tarsal claws dark brown, simple, without basal lobe.

Metasoma reddish brown, much lighter than head and mesosoma, metasomal tergite 2 occupying 1/3 of metasoma length in dorsal view, without basal lateral setae, posterior half punctate, all subsequent tergites and hypopygium uniformly densely punctate; prominent part of ventral spine of hypopygium very short, as long as broad, with very few short sparse white setae ( Fig. 3j ). Body length 3.3–3.6 mm.

MALE. Similar to female, antenna with 12 flagellomeres, F1 slightly curved and excavated, placodeal sensilla from F1 ( Fig. 3d ). Body length 3.1–3.5 mm.

Gall. Galls at the base of flower heads, like in all other Isocolus species , which induce galls in flower heads of Centaurea species (see Melika 2006).

Biology. Galls starting to form in spring, mature in autumn. Adults overwintering in the gall and emerge next year, from mid-April. The only known host plant is Centaurea verutum L. ( Asteraceae ).

Distribution. Currently known from Israel only, although further sampling in similar habitats is required to establish its true distribution. Its host plant, Centaurea verutum L., currently known from Israel (Hebrew) only; a closely related species, Centaurea behen L., is very common in Armenia, Turkey, Israel, Jordan, Syria, Iran, Lebanon, and thus, it is possible that the distribution of newly described species, I. freidbergi , might be broader and can induce galls on C. behen as well.

Figures

FIGURE 3. Isocolus freidbergi n. sp.: a, head (front view); b, head (dorsal view); c, antenna, female; d, antenna, male; e, pronotum (dorsal view); f, mesoscutum and mesoscutellum (dorsal view); g, mesosoma (lateral view); h, propodeum (postero-dorsal view); i, forewing; j, metasoma (lateral view).