Parajapyx isabellae aztecus Silvestri 1948

Montejo-Cruz, Maira, García-Gómez, Arturo & Palacios-Vargas, José G., 2021, Four new species of Parajapyx (Diplura: Parajapygidae) from Mexico with redescription of Parajapyx isabellae aztecus Silvestri, Zootaxa 4948 (2), pp. 221-244 : 238-239

Parajapyx isabellae aztecus Silvestri 1948

Type specimens. Neotype (female) on slide: México, Chiapas, Ocosingo, Reserva Comunal Sierra de la Cojolita. Ex litter rainforest. R. Paredes, col. 18/x/2004 Isoneotype (two males and one juvenile). Same data as neotype. Deposited at “Colección de ácaros y colémbolos”, Facultad de Ciencias , UNAM.

Description. Neotype (female): body length 2.7 mm. Isoneotypes (two males and one juvenile): body length range (n=3) 2.7‒2.9 mm. Cuticle ornamentation in the shape of hexagon cells.

Head vertex ( Fig. 53 ) with 9+9 normal setae and 2+2 normal setae close to the antennae; front with 2+2 macrosetae and 3+3 normal setae; labrum with 1+1 normal setae and 6+6 microsetae. On head venter ( Fig. 54 ) inner lobe with 1+1 normal setae, external lobe with 13+13 normal setae. In place of labial palpus 1+1 macrosetae, 3+3 normal setae, of which two are smaller; admentum with 2+2 macrosetae and 8+8 normal setae; plica orales with 6+6 normal setae, submentum with 2+2 normal setae.

Mandible ( Fig. 55 ) with five teeth and four denticles, maxilla with first lamella slender and slightly larger than half of the second, other lamellae pectinate and similar each other; maxillary palp with 9 normal setae and one apical microsensillum.

Antennae ( Fig. 56 ) with 17 segments, bacilliform setae number in antennal segments as follows: I‒IV,0; V‒VI, 1‒2; VII, 2‒4; X‒XII, 7‒8; XV‒XVI, 9‒10; XVII more than 10 and four placoid sensilla.

Thoracic chaetotaxy is shown in Table 9 ( Fig. 53 ).

Length of Leg III ( Fig. 57 ) 0.2 mm, with smooth setae; coxa with 3 normal setae and one microsetae; trochanter with 3 normal setae and one microsetae; femur with 10 normal setae and 3 microsetae; tibia with 8 normal setae; tarsus with 10 normal setae; claws symmetrical.

Abdominal chaetotaxy is shown in Table 10 ( Figs.58, 59, 60 ).

Tergite VIII twice length of tergite IX (0.13 mm) ( Figs.60, 61 ), tergite IX without macrosetae 4 setae and tergite X without macrosetae 1 ( Fig. 60 ). On sternite I ( Fig. 59 ): prescutum with 4+1+4 or 4+4 normal setae; scutum with 11+11 normal setae and 4+4 microsetae. Typical styles of the genus. Subcoxal organ ( Fig. 62 ) with 5 accompanying setae, 2–3 glandular setae and 4 sensorial setae. On sternite II to VII ( Fig. 59 ) prescutum with 4+1+4 normal setae and 4+4 microsetae; scutum with 14+14 normal setae and 5+5 microsetae. Eversible vesicle present on sternite II and III. Female genital papilla valves ( Fig. 63 ) each with 8 normal setae, one internal microsensillum and 2 external microsensilla. Male genital papilla ( Fig. 63 ) with 4+4 normal setae.

Each cercus ( Figs.64, 65 ) with five internal teeth; D4 smallest, D5 and D3 larger, and D2 and D1 medium and similar with each other, D3 and D1 with bumps. Cerci with one seta a’ close to seta M2. Ventrally, M3 and “b” absent. Each cercus without “d” and 6 pores dorsally; a large pore surrounded by 5 smaller pores, additionally with two normal setae.

Silvestri described this species in 1948 from Baja California Sur and Morelos, there is no register about where he deposited the holotype, original description omits many characters that are currently essential for identification, therefore its redescription is necessary .

Phyletic affinities. P. isabellae aztecus is similar to P. isabellae in the following characters: number of antennal segments (17), thorax and abdominal scutum II to VII chaetotaxy and subcoxal organ with 7 setae. However, it differs in abdominal VIII to X chaethotaxy; abdominal VIII in P. isabellae with 5 normal setae and one seta middle but in P. isabellae aztecus with 7 normal setae; abdominal IX in P. isabellae with 6 macrosetae and 4 normal setae but P. isabellae aztecus one macroseta absent (5 macrosetae total) and 5 normal setae; abdominal X in P. isabellae with 12 macrosetae and 10 normal setae but in P. isabellae aztecus one macroseta absent (11 macrosetae total) and 9 normal setae. In the cercus P. isabellae presents a reduction in the number of setae compared to P. isabellae aztecus ; in P. isabellae dorsal cerci without 6M, c, h, i and a’, ventral cerci without 10M, f, g and h.

Figures

FIGURES 53–57. Parajapyx isabellae aztecus Silvestri 1948; 53. Dorsal view of head and thoracic nota (scale 100 µm). 54. Ventral head (scale 100 µm). 55. Maxilla, mandible and labrum (scale 40 µm). 56.Antennal segments IV, V, XVI and XVII (only the dorsal 15 bacilliform sensilla and 2 placoid sensilla shown for XVII) (scale 70 µm). 57. Leg III (scale 70 µm).

FIGURES 58–61. Parajapyx isabellae aztecus Silvestri 1948; 58. Abdominals tergites I and II (scale 100 µm). 59.Abdominals sternites (scale 100 µm). 60. Tergites VIII‒IX, dorsal view (scale 90 µm). 61. Tergites VIII‒IX, ventral view (scale 90 µm).

FIGURES 62–65. Parajapyx isabellae aztecus Silvestri 1948; 62. Subcoxal organ (scale 10 µm). 63. Female genital papilla (scale 10 µm) and male genital papilla (scale 20 µm). 64. Cerci dorsal view (scale 90 µm). 65. Cerci ventral view (scale 90 µm).