Isocolus karimpouri Melika & Tavakoli, 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 : 28-31

Isocolus karimpouri Melika & Tavakoli , new species

( Figs 6a–j , 7a–c )

Etymology. The species is named in honour of Younes Karimpour, researcher of the Department of Plant Protection, College of Agriculture, Urmia University, Urmia, Iran.

Type material. HOLOTYPE female: Iran, West Azarbaijan , Urmia, ex flower head of Serratula cerinthifolia, IV.2006 . coll. Y. Karimpour. PARATYPES: 6 females and 4 males with the same labels as the holotype. The holotype female and one male paratype are deposited in HNHM ; one female and one male paratypes in RIFR ; 5 female and 2 male paratypes in SPL.

Diagnosis. Belongs to the group of Isocolus species with antero-lateral patch of setae on the metasomal tergite 2 ( Isocolus serratulae (Mayr) , I. lichtensteini (Mayr) and I. leuzeae Nieves-Aldrey & Parra (Melika 2006) . Most similar to a common European species, Isocolus serratulae (Mayr) , which is known to induce galls in flower heads of Serratula species. However, in I. karimpouri n. sp. the mesoscutum with strong transverse rugae, the mesoscutellum dull rugose, while in I. serratulae the mesoscutum and mesoscutellum are delicately coriaceous to regularly reticulate, without transverse rugae.

Description. FEMALE (holotype). Body black; scape and last flagellomere dark brown to black, rest of antenna yellowish brown; coxae, trochanters and basal 2/3 of femora dark brown, tibiae and tarsi yellowish brown; mandibles and palpi yellowish brown, with dark tips; wing veins distinct, dark brown.

Head ( Figs 6a–b ) alutaceous to very delicately coriaceous, only slightly broader than high in front view; 1.9 times as broad as long in dorsal view; slightly broader than mesosoma. POL 1.4 times as long as OOL and 2.1 times as long as LOL, LOL 1.5 times as long as length of lateral ocellus. Gena not broadened behind eye in front view; vertex, interocellar area, occiput alutaceous to very finely coriaceous; postocciput and postgena delicately coriaceous, with more dense white setae as on front. Transfacial distance 1.2 times as long as height of eye, 1.4 times as long as height of lower face (measuring from antennal sockets to ventral edge of clypeus); transfacial distance 4.1 times as long as distance between antennal socket and inner margin of eye; diameter of antennal socket 2.6 times as large as distance between antennal sockets. Lower face alutaceous, with delicate striae, radiating from clypeus and extending into area between antennal socket and eye. Malar space 0.7 times as long as height of eye, with delicate striae, radiating from clypeus and nearly reaching eye margin. Clypeus rectangular, alutaceous to smooth, shiny, rounded ventrally, medially not incised, not emarginated; anterior tentorial pits small, indistinct; epistomal sulcus distinct, broad, impressed, smooth, shiny; clypeo-pleurostomal line indistinct. Antenna with 11 flagellomeres, F1 1.25 times as long as pedicel and slightly shorter than F2; F2–F4 equal in length, subsequent flagellomeres slightly shorter; F11 2.0 times as long as F10; placodeal sensilla on F2–F11 ( Fig. 6c ). Mesosoma black, slightly longer than high in lateral view. Pronotum dorsomedially alutaceous, 1.5 times as short as greatest length measuring on outer margin; uniformly alutaceous to delicately coriaceous laterally; with some parallel wrinkles along antero-ventral margin; with dense white setae along anterior margin, less setae laterally and few setae dorso-medially. Submedian pronotal pit distinct, transversely ovate and deep, separated by broad carina which slightly at least 2.5 times narrower than width of submedian pit; pronotal carina well-delimited in very anterior part, just behind pit, alutaceous ( Fig. 6e ). Mesoscutum black, with strong transverse rugae, with very few sparse short scattered setae; slightly broader than long. Notauli distinctly impressed, complete, smooth, shiny, slightly broadened and converging posteriorly; anterior parallel lines delicate, very short; parapsidal lines indistinct, very narrow, smooth, shiny, extending to 2/3 of mesoscutum length; median mesoscutal line in form of short triangle ( Fig. 6f ). Mesoscutellum rounded, nearly as broad as long; disk uniformly dull rugose, with slightly more delicate sculpture between scutellar foveae, which transverse, broader than high, with dull rugose bottom, indistinctly separated from disk posteriorly and separated from one another by broad median carina ( Fig. 6f ). Dorso-axillar area coriaceous. Mesopleuron, including speculum with uniform transverse delicate striae. Metapleural sulcus reaching mesopleuron in upper 1/3 of its height; axillula delicately coriaceous, with relatively dense white setae; subaxillular bar smooth, shiny, in most posterior part at least 2.0 times as high as height of metanotal trough ( Fig. 6g ). Propodeum black, laterally coriaceous, with relatively dense white setae; lateral propodeal carinae distinct, thin, subparallel, only very slightly curved outwards in posterior half; narrow central propodeal area smooth, mat,without setae, with delicate irregular wrinkles. Metascutellum mat, uniformly coriaceous, very narrow; ventral impressed area of metascutellum indistinct, very short or absent; metanotal trough smooth, without setae; propodeal spiracle transverse, with strong raised carina along anterior border ( Fig. 6h ). Forewing with cilia on margin; R1 and Rs running on a short distance along wing margin, without reaching it; radial cell opened, 3.2 times as long as broad; areolet large, triangular, distinct; Rs+M nearly reaching basalis in its lower half ( Fig. 6i ). Tarsal claws simple, without basal lobe.

Metasoma slightly shorter than head+mesosoma, metasomal tergite 2 antero-laterally with a patch of dense white setae, without punctures; all subsequent tergites and hypopygium with uniform dense punctures; prominent part of ventral spine of hypopygium very short, as long as broad, with very few sparse short white setae ( Fig. 6j ). Body length 2.0– 2.5 mm, holotype female – 2.4 mm.

MALE. Similar to female, antenna with 12 flagellomeres, F1 longest flagellomere, slightly curved and excavated, placodeal sensilla from F2, absent on F1 ( Fig. 6d ). Body length 1.8–2.2 mm.

Gall ( Figs 7a–c ) in stems. Galled stems are without external deformation. Inside the stem slightly elongated (up to 3.5–4.0 mm) where galls are forming, with a thin wall which is not detachable from the inner tissues of the stem; larval chambers are located along the axis of the stem, never across; one larva per cavity ( Fig. 7a ). There are no other Isocolus species , known to induce such a galls. Some Aylacini species such as Panteliella fedtschenkoi (Rübsaamen) , Aulacidea phlomica Belizin , and Phanacis phlomidis Belizin induce such kind of galls in stems of Phlomis tuberosa L. ( Lamiaceae ), however, the larval cells (chambers) in the dry stems are free-rolling; its outer wall is separated from the tissues of the stem, especially after the gall is mature.

Biology. Adults emerge in late April, most likely overwintering in the larval cell in the plant. The only known host plant is Serratula cerinthifolia (Sm.) Boiss. (Asteraceae) .

Distribution. Iran, Western Azarbaijan, Urmia (Ghasemloo, Shohada Valley).

Figures

FIGURE 6. Isocolus karimpouri 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).

FIGURE 7. Isocolus karimpouri n. sp., galls: a, larval chamber, close–up; b, last instar gallwasp larva (photo by Y. Karimpour); c, larval chamber with emerging hole (longitudinal dissection of the stem) (photos by G. Melika).