Allacta unicaudata Li & Wang, 2024

Li, Bian-Lun, Hu, Peng-Hui, Guo, Lin, Che, Yan-Li & Wang, Zong-Qing, 2024, Discovery of five new species of Allacta from Yunnan and Hainan, China (Blattodea, Pseudophyllodromiidae), ZooKeys 1191, pp. 1-21 : 1

Allacta unicaudata Li & Wang sp. nov.

Fig. 4A-Q

Type material

(All in SWU). Holotype: China • male; Yunnan Prov., Pingbian County, Mount Dawei; 1496 m; 15 May, 2016; Lu Qiu, Zhi-Wei Qiu leg. Paratypes: China • 1 male and 1 female, same data as holotype.

Diagnosis.

This species can be easily distinguished from all congeners by the absence of the left stylus in males, except for Allacta lunulara sp. nov., of which males are unknown (see below for females). This species shares a similar appearance with A. lunulara sp. nov., but it can be differentiated from the latter mainly by the following characters of the female genitalia: 1) third valves asymmetrical and slender rod-shaped, while symmetrical and broad crescent-shaped in A. lunulara ; 2) posterior half of basivalvula narrower than the basal half, while basivalvula oval-shaped in A. lunulara ; 3) spermatheca plate rounded with a sharp protrusion in the middle of the spermatheca plate, while front margin of spermatheca plate truncated in A. lunulara ; and 4) laterosternal shelf asymmetrical, narrow, long and slightly curved, while symmetrical, broad and triangular in A. lunulara .

Measurements

(mm). Male, pronotum length × width: 3.7-4.0 × 5.5-5.9, tegmina length: 10.9-12.6, overall length: 14.9-16.0; female, pronotum length × width: 3.7-4.4 × 4.6-5.7, tegmina length: 9.2-11.4, overall length: 11.5-14.7.

Description.

Male. Body yellowish brown (Fig. 4A-D ). Head yellow with ocelli white, frons with a yellowish-brown longitudinal stripe (Fig. 4E ). The third and fourth maxillary palpi dark yellow, and the fifth maxillary palpus brown (Fig. 4G ). Antennae yellowish brown, darkening apically. Lateral borders and front margin of pronotum translucent yellowish, a dark yellow inverted triangular pattern in the middle (Fig. 4F ). Tegmina yellowish orange, clearly uneven in color with radial field, mediocubital field, and anal field darkening basally. Hind wings pale brown (Fig. 4J, K ). Legs yellowish brown. Subgenital plate with posterior half grayish yellow (Fig. 4M ). Cerci yellowish brown, with basal segment darker (Fig. 4L ).

Vertex with interocular space narrower than distance between antennal sockets. The third and fourth maxillary palpi slightly longer than the fifth (Fig. 4G ). Pronotum subparabolic with hind margins truncated (Fig. 4F ). Tegmina and hind wings fully developed, both extending beyond the end of abdomen. Tegmina slender, with M and CuA longitudinal, CuA with four branches (Fig. 4J ). M of hind wings with two branches, CuA curved with three complete branches (Fig. 4K ). Anteroventral margin of front femur Type B3 (Fig. 4H ). Pulvillus only present on the fourth tarsomere. Tarsal claws symmetrical and unspecialized, arolium present.

Male abdomen and genitalia. Abdominal terga unspecialized. Supra-anal plate short, symmetrical, with hind margin slightly concave. Paraprocts simple and plate-like (Fig. 4L ). Subgenital plate asymmetrical with a V-shaped notch at the interstylar margin, without left stylus, right stylus cylindrical arising in a concavity of the hind margin near right posterolateral corner (Fig. 4M ). Left phallomere complex (Fig. 4N ). Median phallomere (L2vm) stem slender, rod-like, slightly curved, apex bluntly round with a small spine; median phallomere subsidiary sclerite (R3) C-shaped, apex sharp with a brush-like structure (Fig. 4O ). Hooked phallomere (R2) on the right of subgenital plate, with pre-apical incision (Fig. 4P ).

Female genitalia. Supra-anal plate nearly symmetrical. Paraprocts broad. Intercalary sclerite irregular plate-shaped and translucent. First valves robust, with inward protrusions. Second valves small. Third valves asymmetrical, slender rod-shaped, and the left branch obviously curved outward. The anterior margin of anterior arch slightly sclerotized. First valvifer long and narrow plate-like with setae on the inside. Basivalvula spindle-shaped, wide in the middle and tapers at both ends. Laterosternal shelf asymmetrical, narrow, long and slightly curved. Front margin of spermathecal plate rounded with a sharp protrusion in the middle. The spermatheca lobe forked, the end of one spermatheca branch enlarged, and the other long and tubular (Fig. 4R, S ).

Remarks.

This species resembles A. alba , but it can be differentiated from the latter by the following characters: 1) pronotal disc with an inverted triangular yellowish spot, while with subtrapezoidal symmetrical white markings in A. alba ; 2) tegmina and hind wings slightly extending beyond the end of the abdomen, while extending far beyond the end of the abdomen in A. alba ; and 3) subgenital plate without left stylus, while with two styli in A. alba . This species is placed in the hamifera species group by having the male interstylar margin broadly V-shaped.

Etymology.

The Latin words uni - meaning one, single, and caudata meaning tailed, referring to subgenital plate with only one stylus.

Distribution.

China (Yunnan).

Figures

Figure 4. Allacta unicaudata sp. nov., male holotype A dorsal view B ventral view C paratype (female), dorsal view D paratype (female), ventral view E head, ventral view F pronotum, dorsal view G maxillary palpi, ventral view H front femur, ventral view I tarsus and tarsal claws of front leg J tegmen, dorsal view K hind wing, dorsal view L supra-anal plate and paraprocts, ventral view M subgenital plate, dorsal view N left phallomere, dorsal view O median phallomere, dorsal view P hook-like phallomere, dorsal view Q female subgenital plate, dorsal view. Scale bars: 5 mm (A-D); 1 mm (E-Q). Abbreviations: a. a. anterior arch, bsv. basivalvula, intc. s. intercalary sclerite, ltst. sh. laterosternal shelf, pp. paraprocts, pt. paratergites, sp. pl. spermathecal plate, vlf. I first valvifer, v. I first valves, v. II second valves, v. III third valves. For vein abbreviations see Material and methods.