Keesia nana, Mitroiu, 2016

Mitroiu, Mircea-Dan, 2016, Pireninae (Hymenoptera: Pteromalidae) of Papua New Guinea: key to genera and description of new taxa, Mémoires du Muséum national d'Histoire naturelle 209, pp. 307-320 : 312-314

Keesia nana n. sp.

(Figures 2-4)

TYPE MATERIAL – Female holotype, Papua New Guinea. PNG, Wanang, 18- 19.11.2012, PNG MAL-WAN03-D01, P4932 /9227 ( MNHN). Paratypes: Papua New Guinea, 2 ♀, PNG, Wanang, 3- 4.12.2012, PNG MAL-WAN02-D16, P4931 /11078 ( MNHN); 1♀, idem, P4915 /11066 ( MNHN); 1♀, PNG, Wanang, 28- 29.11.2012, PNG MAL-WAN01-D11, P4910 /2113 ( MNHN); 1♀, PNG, Wanang, 21- 22.11.2012, PNG MAL-WAN01-D04, P4903 /9047 ( MICO); 2♀, PNG, Wanang, 29- 30.11.2012, PNG MAL-WAN01-D12, P4911 /982 ( MICO).

ETYMOLOGY — The name of the species points to the small size of this insect.

DIAGNOSIS — Female. Mesosoma flattened, but pronotum moderately steep (Figure 2); obsolete r-m vein with at most two setae on upper side of fore wing (Figures 3-4); metasoma slightly longer than mesosoma (Figs 3-4); first three gastral tergites larger, last ones partly retracted (Figure 4); ovipositor sheaths slightly less than half length of hind tibia; hypopygium reaching tip of metasoma (excluding ovipositor sheaths) (Figure 3).

DESCRIPTION — FEMALE: Holotype (Figures 2-4). Body length. 1.25 mm. Color. Body blackish-brown, with slight bronze reflections. Eyes and ocelli pale red. Mandibles reddish-yellow. Antenna dark brown. Legs brown; extreme apices of tibiae and tarsi except last segment yellowish; last tarsal segment and claws brown. Wings hyaline, tegulae and venation brown (Figures 2-4). Head mostly smooth and shiny except slightly coriaceous lower face, between scrobes and eyes, and with several erect setae mostly on lateral sides of face and vertex. Antenna with all flagellar segments before clava anelliform, strongly transverse and gradually increasing in diameter. Clava large, conspicuously wider than fl5 (Figure 2). Relative measurements: head length: 15, width: 32, height: 40; POL: 10; OOL: 5; eye height: 25, length: 15; IOD: 25; malar space: 6; scape length: 16; pedicel length: 7, width: 4; pedicel plus flagellum: 28; fl1-5 combined length: 5; clava length: 16, width: 8. Mesosoma smooth and shiny, with several long sparse erect setae on dorsal side (Figure 2). In lateral view mesosoma appearing almost flat, except moderately steep pronotum and inclined frenal area (Figure 3). Dorsellum semicircular, overlapping for a short length the base of propodeum (Figure 4). Relative measurements: mesosomal length: 49, width: 32, height: 21; mesoscutum length: 15; scutellum length: 15, width: 20; dorsellum length: 10; propodeum length: 5; fore wing length: 100, width: 35; M: 30; S: 2; P: 1; hind tibia length: 22. Metasoma elongate, moderately compressed laterally and dorsally flat (Figures 3-4). Posterior margin of gastral tergites almost straight except for gt2, where it is conspicuously curved backwards (Figure 4); gt4-gt7 with a few long erect setae on lateral sides. Hypopygium

FIGURES 1-6

1, Gastrancistrus sp. , female, habitus, lateral view; 2-4, Keesia nana n. sp.,female holotype, head and anterior part of mesosoma in lateral view (2), habitus in lateral (3) and dorsal views (4); 5-6, Macroglenes longiclava n. sp.,female holotype,habitus in lateral (5) and dorsal views (6). Scale bars = 0.25 mm.

reaching tip of metasoma (Figure 3). Relative measurements: metasomal length: 71, width: 29; gt1 length: 15; gt2 length:

15; gt3 length: 16; gt4-gt7 length: 20; ovipositor sheaths length: 12.

MALE: unknown.

VARIATION — Females. Body length: 0.60-1.25 mm. Colour of eyes from pale to bright red. Most of the female paratypes have various body parts (especially the head) more or less collapsed, thus preventing accurate measurements. In most examined specimens the mesoscutum is completely flattened (probably the result of the drying process), but in one female it is slightly convex. Mesosoma length about 2.0-2.3× height.

REMARK — In the female holotype the pecten could not be measured, but it was observed to occupy about 2/3 length of hind tibia in several female paratypes. Previously, two species of Keesia have been described and keyed ( Mitroiu 2011). The newly described species can be separated from them as follows:

1. Mesosoma convex, length about 1.6× height; dorsellum about 1.7× as long as median length of propodeum; ovipositor sheaths about half length of hind tibia .................................................................... K. dorsellata Mitroiu – Mesosoma flattened, length about 2.00-2.75× height; dorsellum about 2.0-2.4× as long as median length of propodeum; ovipositor sheaths sometimes shorter ...................................................................................................... 2

2. Pronotum more or less horizontal, not steep; mesosoma length 2.75× height; obsolete r-m vein with seven setae; dorsellum about 2.4× as long as median length of propodeum; ovipositor sheaths about 1/3 length of hind tibia ............................................................................................................................................... K. tripotini Mitroiu – Pronotum steep; mesosoma length about 2.0-2.3× height; obsolete r-m vein with at most two setae; dorsellum about twice as long as median length of propodeum; ovipositor sheaths about half length of hind tibia ............................................................................................................................................................................. K. nana n. sp.