Bracon (Glabrobracon) planitibiae Yang, Cao et Gould, 2019

Cao, Liang-Ming, Wang, Xiao-Yi, Gould, Juli-Ruth, Li, Fei, Zhang, Yan-Long & Yang, Zhong-Qi, 2019, Bracon planitibiae sp. nov. (Hymenoptera: Braconidae), a new parasitoid of Asian longhorned beetle (Anoplophora glabripennis), Zootaxa 4671 (3), pp. 427-433 : 430-433

Bracon (Glabrobracon) planitibiae Yang, Cao et Gould , sp. nov.

( Figs 7–15 )

Type materials. Holotype, 1♀, China, Beijing City, Haidian Distinct, Minzhuang Road , N39°58′15″, E116°12′45″, 2016.VIII.4, reared from a cocoon collected from the gallery of ALB first instar larva in the sentinel logs hanging in willow forest for one month, Yang Zhongqi & Li Fei leg. Paratypes, 6♀♀, same data as holotype .

Female. Body length 2.79–3.33 mm, fore wing length 3.02–3.15 mm.

Color. Body black. Two spots under antennal toruli yellow ( Fig. 9 ); sides of first tergite white; malar suture and adjacent area, basal mandible, tibial spurs, basal tibia and apical tarsus yellow to dark yellow. Wings hyaline, pterostigma brown, veins light brown. Setae of head, mesopleuron, mesoscutum, propodeum golden.

Head ( Figs 7–10 , 12 ). Median length 2/3 of its width in dorsal view; vertex smooth, with sparse long setae, but setae on occiput shorter; eyes large, transverse diameter 1.63 × length of temple in lateral view; face with dense long setae and reticulate; front clypeal suture bent intensely, anterior tentorial pit large bilaterally; clypeus narrow, oral cavity deeply depressed; malar suture 1/6 of height of eye and 1/5 basal width of maxillary palp; mandible strong with long thick setae, upper margin with one big tooth; antenna 28 antennomeres ( Figs 7, 8, 10 ), scape twice of pedicel length, antenna about 0.75 × body length, and 0.79 × fore wing length.

Mesosoma ( Figs 7, 8, 11 , 12 ). In lateral view, length 1.48 × maximum height; pronotum depressed in the middle, smooth and shining; propleuron with long setae marginally; mesopleuron smooth, broad and swollen downwards, with sparse long setae medially; in dorsal view, mesoscutum smooth with sparse long setae; notauli depressed without any sculpture, mid pit lacking; scutellar sulcus narrow and deep, with 12–15 round sculptures; apical and lateral scutellum with dense long golden setae; length of metanotum 0.29 × propodeum length; propodeum smooth, most central part with dense long setae bilaterally.

Legs ( Figs 7, 8 , 14 ). Fore trochantellus 0.4 × length fore femur, the latter as long as fore tibia and about 0.6 × length fore tarsus; apical spur of fore tibia 1/2 of basitarsus, each tarsomere with thick setae apically, length ratio of fore tarsomeres I–V = 2:1:0.8:0.5:1. Mid tibia slightly longer than femur, apical two spurs 1/3 length basitarsus, length ratio of mid tarsomeres I–V = 1.5:0.7:0.6:0.5:0.7. Hind femur depressed, 2.8 × as long as broad, with inner side very flattened and outer side only evenly convex, 2.4 × as wide as thick; hind tibia very flattened and 1.3 × the femur, 6.4 × as long as broad, and 1.8 × as wide as thick; hind tarsomere 1–4 considerably flattened bilaterally.

Wings ( Fig. 13 ). Fore wing 2.84 × as long as its maximum width; pterostigma 2.6 × as long as its width; 1- R 1 about 1.40 × length of pterostigma; radial vein arising from middle pterostigma; SR1 about 2.0 × length of 3-SR; radial vein about 0.65 × length of 2-SR, and 0.58 × length of 3-SR; cu-a vein straight, 1-CU1 vein invisible; m-cu vein enters into first submarginal cell; 2-SR+M and basal 2-M weakly sclerotized; 1-SR+M vein straight; 3-M and CU1a vein reaching apex of fore wing; 3-CU1 vein bent. Hind wing 3.5 × as long as its maximum width; cu-a vein 0.63 × length of M+CU, and 0.3 × length of 1-M; 2-M and SR intensely sclerotized.

Metasoma ( Figs 7, 8 , 15 ). Oblong, first tergite quadrate, with two rows of oblique punctations, spiracles located at 1/3 basally, triangular broadening side as wide as first tergite; tergites 2–7 smooth, with even long golden setae; suture between tergites 2–3 deep, with granulose punctations. Ovipositor sheath short, as long as hind tibia; ovipositor golden and sharp.

Male. Unknown.

Distribution. China (Beijing).

Etymology. The new species name is derived from its flattened hind tibia.

Diagnosis. The new species is similar to B. (Glabrobracon) nigriventris Wesmael , which is also a parasitoid of cerambycids, and the two species can be separated with the key below.

1 Face with two yellow spots under antennal toruli ( Fig 9 ); propodeum completely polished and shining ( Fig 11 ); hind femur depressed, only 2.8 ×as long as broad; hind tibia and hind tarsomere 1–4 considerable flattened; ovipositor sheath short, as long as hind tibia ( Fig 8 )............................................................... Bracon planitibiae sp. nov.

- Face without yellow spots under antennal toruli ( Papp, 2012); propodeum having short rugae above lunule ( Papp, 2012 p62, Fig 28C); hind femur 3.0 × as long as broad; tibia and tarsomere 1–4 normal and not flattened; ovipositor sheath long, as long as hind tibia + basitarsus combined ( Papp, 2012)..................................... Bracon nigriventris Wesmael

Biological observations. The new species is a solitary ectoparasitoid of first instar larvae of Anoplophora glabripennis . Percentage parasitism averaged 4.0% during the three year study, with a maximum of 5.9% in 2017. The newly emerged larva of the parasitoid is attached to the host body. In only seven days the host was completely consumed and the mature parasitoid larva made a cocoon beside the mummy of the host. The pupal stage of the parasitoid lasted 18–20 days at a temperature of approximately 25°C.

Figures

FIGURES 7–11. B. planitibiae sp. nov. (female) 7, Habitus in dorsal view. 8, Habitus in lateral view. 9, Head in front view. 10, Head and antennae in lateral view. 11, Propodeum in dorsal view.

FIGURES 12–15. Bracon planitibiae sp. nov. 12, Head and mesosoma in dorsal view. 13, Wings. 14, Hind left leg (without coxa). 15, Metasoma in dorsal view.