Mistaria nairobii (Caporiacco, 1949)

Kioko, Grace M., Kioko, Esther N., Li, Shuqiang & Ji, Liqiang, 2018, On four species of the genus Mistaria Lehtinen, 1967 (Araneae, Agelenidae) from Kenya, African Invertebrates 59, pp. 111-126: 111

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Mistaria nairobii (Caporiacco, 1949)

comb. n.

Mistaria nairobii (Caporiacco, 1949)  comb. n. Figs 2, 3

Synonyms: Agelena leucopyga nairobii  Caporiacco, 1949 ( Caporiacco 1949: 329, fig. 7, ♂♀); Agelena nairobii  Caporiacco, 1949 in Roewer (1955: 46, fig. 16 a–c, ♂♀).

Type material examined.

Lectotype, ♂, Kenya, Nairobi, 1944, Meneghetti ( NMLS).

Other materal examined.

1♀, Kenya, Kakamega County, Kakamega Town, Kakamega Forest, Isecheno forest station, Mutere Trail, N00°17.300', E34°51.220', 1,630 m a.s.l., 15th July 2017, Q. Zhao. & G. Kioko ( NMK).


Males of this species can be distinguished from M. leucopyga  by the size ratio of the retrolateral tibial apophysis to the lateral tibial apophysis, which is 3:1 compared to 5:1 in the latter species (Fig. 2B). Compared to M. nyeupenyeusi  G.M. Kioko & S. Li, sp. n., M. nairobii  is relatively large. The colour pattern can also be used to separate the two species whereby M. nyeupenyeusi  G.M. Kioko & S. Li, sp. n. is generally black and white compared to brown-yellow in M. nairobii  . The females of M. nairobii  can be separated from M. leucopyga  and M. fagei  by the circular lobes of the retrolateral spermatheca compared to ovoid lobes in the latter two species (Figs 1B, 3B).


Male. Total length 11.86. Carapace 5.77 long, 4.49 wide. Abdomen 6.09 long, 3.85 wide. Habitus as in Fig. 3C. Carapace rounded, red-brown with numerous white setae and distinct pattern comprising four pairs of lateral bands (Fig. 5A). Eye sizes and interdistances: AME 0.28, ALE 0.31, PME 0.28, PLE 0.32, AME–AME 0.09, AME–ALE 0.06, PME–PME 0.20, PME–PLE 0.25. Chelicerae, labium and endites red-brown. Sternum brown, indistinct median band. Legs brown. Leg measurements: II 19.62 (5.51, 6.71, 4.80, 2.60). Legs I, II and IV missing. Abdomen oval, cream-white with black spots, four chevron markings, ventre with a pair of horizontal black stripes. Posterior spinneret segments equal in size, brown.

Palp as in Fig. 2A, C. Cymbium 2.56 long, rounded and thick, red-brown with a creamy apex and tip about 1/3 the length of cymbium (Fig. 2B). Cymbial furrow short, about 1/6 length of cymbium. Retrolateral tibial apophysis triangular, 1.5 times the length of the tibia (Fig. 2C). Apex blunt with a small adjacent lateral tibial apophysis. Size ratio of the retrolateral tibial apophysis to the lateral tibial apophysis: 3:1 (Fig. 2B). Patellar apophysis cone-shaped, approximately as long as the tibia. Edge of sub-tegulum slanting at point of attachment to fulcrum (Fig. 2C). Median apophysis has a wide base and a narrow apex, curved at the apex (Fig. 2B). Conductor resembles a thumb that is bent backward. Embolus originating centrally with basal embolic outgrowth, with a slight curve for the base and basal membrane (Fig. 2A).

Female. Total length 12.5. Carapace 4.2 long, 3.9 wide. Abdomen 8.3 long, 5.5 wide. Habitus as in Fig. 3D, E. Carapace light brown, with four pairs of lateral bands. Eye sizes and interdistances: AME 0.28, ALE 0.3, PME 0.2, PLE 0.24, AME–AME 0.13, AME–ALE 0.1, PME–PME 0.25, PME–PLE 0.3. Cephalic region, chelicerae, labium and endites red-brown. Coxa and femur of all legs brown suffused with black, the rest of the segments brown. Leg measurements: I 15.12 (3.90, 5.81, 3.51, 1.90), II 14.71 (4.20, 5.10, 3.50, 1.91), III 13.12 (3.80, 4.51, 3.21, 1.60) IV 16.11 (4.81, 5.50, 4.50, 1.30). Abdomen rounded with three chevron marks dorsally, red-brown with black and white spots. Horizontal bands cream-white anteriorly and black posteriorly. Ventre with horizontal black lines outlined with cream-white. Distal segment of the posterior spinnerets same size as the proximal segment.

Epigyne as in Fig. 3A, B. Teeth wide posteriorly and narrow distally, slightly longer than the lateral notches, central origin (Fig. 3A). Spermathecae lobes and copulatory ducts rounded, anterior lobe slightly darker than the middle and posterior lobe (Fig. 3B). Copulatory ducts sclerotised and of basal origin. Epigyne and vulva delimiting edges concave.


Central and East Africa (Fig. 7).