Ismarus areolatus Chen, 2021

Zhang, Xiao, Chen, Hua-yan, Liu, Jing-xian & Luo, Shi-xiao, 2021, The genus Ismarus Haliday (Hymenoptera, Ismaridae) from China, Journal of Hymenoptera Research 82, pp. 139-160 : 139

Ismarus areolatus Chen sp. nov.

Figures 2 , 3

Diagnosis.

This species can be easily distinguished from other Oriental species of Ismarus by the following characters: lateral pronotal area with a submedian oblique carina; mesoscutellum areolate and posterior rim excavate with slightly prominent posterolateral corners; hind tibiae abruptly incrassate.

Description.

Female. Body length 2.24-3.15 mm.

Colour. Body black; A1-A2 brown, remainder of antenna black; coxae of fore and mid legs black, remainder brown to yellow, with tibia and tarsi becoming paler, hind leg mostly black with trochanter dark brown; wings hyaline, veins blackish brown.

Head. Head in dorsal view 2.0 × as wide as long; vertex abruptly sloping behind ocelli; POL as long as OOL; frons with ventrolateral areas densely setose, area below anterior ocellus with scattered setae; facial transverse carina slightly convex ventrally; A3 slightly longer than A4; A4 1.2 × length of A5; A6-A14 with each segment less than 1.5 × as long as wide; A15 approximately 2.0 × longer than wide.

Mesosoma. Dorsal pronotal area rugose-punctate and setose; lateral pronotal area with a submedian oblique carina, rugose ventrally, smooth dorsally; mesoscutum smooth and convex, posterior margin with relatively dense long setae; mesoscutal suprahumeral sulcus absent; humeral sulcus deep and crenulate, 1.7 × length of tegula; mesoscutellum areolate and slightly convex, posterior rim excavate with slightly prominent posterolateral corners; anterior mesoscutellar pit large and deep, as long as length of the mesoscutellar disc, distinctly crenulate posteriorly, median keel strong; mesopleuron smooth and bare, with area below tegula rugulose; metapleuron rugose and covered with dense whitish long setae.

Wings. Radial cell completely closed, very small, 4.4 × as long as wide and 0.2 × as long as marginal vein.

Legs. Fore and mid legs slender; hind tibia abruptly incrassate, its maximum width slightly wider than hind femur.

Metasoma. Petiole distinctly transverse, with strong costae dorsally; base of T2 with six short costae, median furrow short, 0.15 × length of T2, remainder of T2 smooth with scattered fine punctures; T3-T7 smooth with scattered fine punctures; T8 coriaceous; sutures between tergites complete and deeply impressed.

Male. Unknown.

Etymology.

The name refers to the areolate mesoscutellum.

Material examined.

Holotype, female: China: Guangdong, Guangzhou, South China Botanical Garden , forest, 23°10'49.87"N, 113°21'21.33"E, MT1, 7.iv-7.v.2020, Jian-wei Li, SCAU 3049372 (deposited in SYSBM) . Paratype: (1 female) China: Guangdong, Maoming, Yunkaishan National Nature Reserve , LSX591, MT-GD32, 22°16'38.37"N, 111°11'45.23"E, 30.iv-29.v.2020, Long-long Chen, SCAU 3049371 (SYSBM) .

Figures

Figure 2. Ismarus areolatus Chen, sp. nov., holotype, female (SCAU 3049372) A lateral habitus B head, anterior view C head and mesosoma, dorsal view D head and mesosoma, lateral view E propodeum and basal metasoma, dorsal view F apical metasoma, dorsal view.

Figure 3. Ismarus areolatus Chen, sp. nov., holotype, female (SCAU 3049372) A wings B antenna C hind tibia.