Beybienkonus acuticercus (Bey-Bienko, 1957) Bey-Bienko, 1957

Qiu, Lu, Wang, Zong-Qing & Che, Yan-Li, 2019, New and little known Latindiinae (Blattodea, Corydiidae) from China, with discussion of the Asian genera and species, ZooKeys 867, pp. 23-44 : 23

Beybienkonus acuticercus (Bey-Bienko, 1957) comb. nov. Figs 6 , 7 , 8 , 9 , 10 , 11 C–F

Ctenoneura acuticerca Bey-Bienko, 1957: 896 (original description); Princis 1963: 101 (catalogue); Roth 1993: 87; Feng et al. 1997: 34 (catalogue); Qiu et al. 2017: 297.

Material examined.

CHINA: Yunnan: 5 males (brachypterous), 3 females (macropterous), 10 females (brachypterous), and more than 30 nymphs (under rearing): around Mangyun Township [芒允乡], Yingjiang County [盈江县], Dehong Prefecture [德宏景颇族自治州], 24°34'N, 97°45'E, alt. ca. 800-1300 m, 27. II– 11.III.2018, Gui-Chang Liu (local people) leg.; Tibet: 3 females (brachypterous): Gelin Village [格林村], Bengbeng Township [背崩乡], Medog County [墨脱县], Nyingchi City [林芝市], alt. 1600 m, 15.VII.2016, Hao Xu et Jian-Yue Qiu leg. (all in SWU).

Description.

Brachypterous male. General: measurements (mm): body length (vertex to abdomen tip): 10.1-10.6, pronotum length (midline) × width (the widest points): 3.1-3.2 × 4.6-4.8, tegmen length: 4.9-5.1, tegmen width: 2.7-2.8. Size small, body smooth, brownish yellow ( Fig. 6 A, B ). Head: longer than width. Vertex slightly exposed under pronotum, convex, darker than the remaining part of head. Eyes small, wide apart; interocular space much greater than the distance between ocelli and antennal sockets. Ocelli represented as two white spots, situated above antennal sockets. Frons smooth, two brown spots situated between the lower parts of the antennal sockets. Antennal sockets small. Antennae dark brown, shorter than the body length (8.6-10.3 mm). Face smooth, large. Clypeus small, nearly trapezoidal, the edge between ante-clypeus and post-clypeus indistinct. Labrum small, sub-triangular. Maxillary palpi long ( Fig. 8A ). Pronotum: light brownish yellow, lateral parts sub-transparent. Smooth, surface without pubescence, but very sparsely with micro setae ( can’t be observed by naked eyes, even easily overlooked under microscope). Shape semi-oval, widest at 1/4 from the base, hind angles round ( Fig. 8B ). Tegmina and wings: both reduced, flightless. Tegmen smooth, brown, reaches to the 4th or 5th tergum, nearly rectangular, apical portion slightly protruding, overall outline slightly rounded; venation simple. Wing small, elongate, curved, reaching the apex of 2nd or 3rd tergum ( Figs 6A , 9C, D ). Legs: smooth, brownish yellow, sparsely covered with short setae, hind legs robust. Front femur with a row of small spines at hind margin, ending with a long spine at apex (type C1) ( Fig. 8F ), while in middle and hind femur without row of spines at hind margin; in middle and hind legs, each femur with a long spine at anterior apex and two long spines at hind apex; in hind femur, the two spines at hind apex extremely robust and long. Tibia with a spinous protrusion at apex (small in front and middle tibiae, extremely long in hind tibia); surface of tibia normally with some long spines, the spines at tibial apex longer than the spines at tibial surface; in hind tibia, two of the apical spines extremely long (one is thin and straight, the other is robust and curved) ( Fig. 8D ). Tarsi covered with many spines; the length of tarsus 1 sub-equal to the total length of tarsus 2 to 5; tarsal claws normal, symmetrical, moderate in size; arolia absent ( Fig. 8G ). Abdomen: smooth, brownish, terga without modification, lateral margins with small spinous pubescence. Supra-anal plate ( Fig. 10A ) pubescent, narrowly triangular, apex with two rounded lobes; paraprocts simple; cerci long, smooth and without pubescence dorsally, with pubescent ventrally, apex with a very long and sharp spine ( Fig. 8H, I ). Subgenital plate simple, sparsely pubescent, base with rough setae laterally; styli slender ( Fig. 10B ). Genitalia: Left phallomere: L1 consists of two irregular sclerites, the dorsal one slice-like, the ventral one with three unequal-sized protrusions; L2 thick, straight; L3 small, curved, S-shaped; L4N simple, straight; L4M small, slice-like. Right phallomere: large. R3 and R1M elongate; R2 with two sclerites, the ventral one stout, irregularly rounded, the dorsal one extremely long, irregular, lays across the whole phallomere ( Figs 10 C–D ).

Brachypterous female.

Measurements (mm): body length: 8.9-10.5, pronotum length × width: 3.0-3.2 × 4.5-4.7, tegmen length: 4.4-4.7, tegmen width: 2.5-2.7. Generally similar to the brachypterous male, but eyes slightly smaller than that of the male, antennae shorter than the body length ( Fig. 6C, D ). Tegmen shorter, apex truncated, only reaching half of the 3rd or 4th tergum; wing much more reduced, only reaching the 1st tergum; venation simple ( Fig. 9E, F ). Spines on legs normal, not elongated or enlarged ( Fig. 8E ). Supra-anal plate trapezoid-shaped, apex rounded, median slightly concaved, margin and ventral surface setose ( Fig. 10E ). Subgenital plate valved ( Fig. 10F ).

Macropterous male.

Unknown.

Macropterous female.

Measurements (mm): body length: 9.2-9.4, total length: 10.9-12.5, pronotum length × width: 2.3-2.6 × 3.2-3.6, tegmen length: 8.9-10.1, tegmen width: 2.9-3.1 ( Figs 7 A–B ). Head and legs the same as the brachypterous females. Pronotum sub-oval, wider than long, hind margin slightly truncated ( Fig. 8C ). Tegmina and wings fully developed. Tegmen with a thick and simple ScP, ScP area articulated with many small veins; R with four branches; M with two long branches that are parallel with the main vein; CuA bifurcated at basal half, near the middle, an isolated vein present, with many articulated cross veins connecting it with the main vein of CuA. Wing with a single ScP and RA; RP simple, with many thin veins; M bifurcated medially; CuA with four curved and parallel branches; CuP and Pcu simple ( Fig. 9A, B ). Abdomen slightly narrower than the brachypterous female.

Nymph.

Large nymphs light brownish yellow, sub-transparent, densely pubescent ( Fig. 12A ).

Ootheca.

Flat, rounded, with only two eggs, dense serrations present at the keel ( Fig. 12D ).

Natural history.

Individuals were captured from rotten wood, or under the barks of the rotten wood ( Fig. 11C, D ). Under the lab condition, individuals can feed on bread crumbs and apple pieces; one can prevent the others from grabbing its food by kicking (by the strong hind legs), or fast running away with food (food were carried by front legs). Females were noticed producing oothecae in April ( Fig. 12C ), the nymphs were very fast hatched around 10-15 days.

Distribution.

China (Yunnan and Tibet) ( Fig. 13 ).

Remarks.

Bey-Bienko (1957) described Ctenoneura acuticerca based on two females from Yunnan, China. From the original description, C. acuticerca is characterised by the smooth pronotum, absence of intercalary vein and arolia, triangular supra-anal plate with emarginate, valvular subgenital plate, and cerci with a large spine apically. Bey-Bienko (1957) himself had indicated C. acuticerca is related to Ctenoneura aberrans Hanitsch, 1928. However, C. aberrans had been moved to genus Homopteroidea since this species is quite different from Ctenoneura ( Roth 1995a). Later, Qiu et al. (2017) doubted C. acuticerca Bey-Bienko, 1957 to be a Ctenoneura species according to the absent intercalary vein and arolia, and the female Ctenoneura was found to be apterous. However, due to no specimens of Ctenoneura acuticerca being available, the problem remained unsolved.

Recently we obtained abundant living individuals of Ctenoneura acuticerca from Yingjiang, Yunnan. These roaches were captured from the same locality in the rotten woods. We noticed that this species displays polymorphism. Most individuals are brachypterous, while individuals were very rarely macropterous in the material we examined ( Fig. 12B ). We compared the brachypterous and macropterous individuals both by morphological features and the COI sequences (one brachypterous male, one brachypterous female and one macropterous female were sequenced, GenBank access numbers MN116497, MN116498 and MN116500, respectively). Both results showed that the brachypterous and the macropterous individuals are conspecific: 1) morphologically, the brachypterous individuals and the macropterous individuals show no differences but in the shape of pronotum and the length of tegmina and wings; and 2) the divergence of COI sequences between the brachypterous male and the macropterous female is 0%, and the divergence between the brachypterous female and the macropterous female is 0.2%. Thus, we confirmed the brachypterous and the macropterous individuals are the same species. Meanwhile, we also sequenced one of the Tibetan specimens by COI (GenBank access number MN116495), and found the divergence between the Tibetan specimen and the Yunnan specimen is only 4.3%-4.4%. Thus, we can confirm that the Tibet individuals are conspecific with the Yunnan individuals.

After a carefully study of Ctenoneura acuticerca , we readily confirmed that this species should be excluded from the genus Ctenoneura by the winged female, the complex male genitalia with genital hook, and the simplified venation without intercalary vein; and it does not belong to any of the other genera in Corydiidae . We herein establish genus Beybienkonus gen. nov. to accommodate C. acuticerca . Thus, Beybienkonus acuticercus (Bey-Bienko, 1957), comb. nov. is proposed.

Figures

Figure 6. A-D Beybienkonus acuticercus (Bey-Bienko, 1957), comb. nov., brachypterous individuals from Yunnan A male, dorsal view B same, ventral view C female, dorsal view D same, ventral view. Scale bar: 2 mm.

Figure 7. A-B Beybienkonus acuticercus (Bey-Bienko, 1957), comb. nov., macropterous female from Yunnan A dorsal view B ventral view. Scale bar: 2 mm.

Figure 8. Beybienkonus acuticercus (Bey-Bienko, 1957), comb. nov., individuals from Yunnan A head, brachypterous male, ventral view B pronotum, brachypterous male, dorsal view C pronotum, macropterous female, dorsal view D part of the hind leg, male E part of the hind leg, female F front femur, male G tarsal claw, male H cercus, male, dorsal view I cercus, male, ventral view. Scale bars: 0.5 mm.

Figure 9. Tegmina and wings of Beybienkonus acuticercus (Bey-Bienko, 1957), comb. nov., individuals from Yunnan A tegmen, macropterous female B wing, macropterous female C tegmen, brachypterous male D wing, brachypterous male E tegmen, brachypterous female F wing, brachypterous female. Scale bars: 0.5 mm.

Figure 10. Beybienkonus acuticercus (Bey-Bienko, 1957), comb. nov., individuals from Yunnan A supra-anal plate, male, ventral view B subgenital plate, male, ventral view C genitalia, male, original position D genitalia, male (dissected) E supra-anal plate, female, dorsal view F subgenital plate, female, ventral view. Scale bars: 0.5 mm.

Figure 11. Habitats of Latindiinae from China A habitat of Brachylatindia xui gen. et sp. nov., Shangchayu, Chayu, Tibet B habitat of Brachylatindia sp., Guxiang, Bomi, Tibet C-D habitat of Beybienkonus acuticercus (Bey-Bienko, 1957), comb. nov., Motuo, Tibet D a living B. acuticercus (Bey-Bienko, 1957), comb. nov., found in rotten wood. All photographs by Hao Xu.

Figure 12. Beybienkonus acuticercus (Bey-Bienko, 1957), comb. nov. from Yingjiang, Yunnan, under lab conditions A nymphs B macropterous and brachypterous females. C brachypterous female with ootheca (black arrow indicated) D ootheca. Scale bar: 0.5 mm. All photographs by Lu Qiu.

Figure 13. Distribution map of Latindiinae from Asia.