Centrozoros hamiltoni New, 1978

Kocarek, Petr & Horka, Ivona, 2022, Identity of Zorotypus juninensis Engel, 2000, syn. nov. revealed: it is conspecific with Centrozoros hamiltoni (New, 1978) (Zoraptera, Spiralizoridae), Deutsche Entomologische Zeitschrift 69 (1), pp. 65-70 : 65

Centrozoros hamiltoni New, 1978

Figs 1 , 2

Zorotypus juninensis Engel, 2000 syn. nov.

Note.

New 1978: 365-368 (description, illustration, keyed); Hubbard 1990: 52 (catalog of world species); Choe 1989: 150 (distribution map); Choe 1992: 250 (distribution map); Engel 2000: (description of Z. juninensis , syn. nov.); Choe 2018: 200 (distribution); Mashimo et al. 2019: 753 (distribution); Matsumura et al. 2020: 352-357 (distribution, phylogenetic relationships); Kočárek et al. 2020: 11-12, 14-15 (male genitalia, classification).

Studied type material.

Centrozoros hamiltoni (New, 1978) - Holotype: Colombia · 1 apterous ♂; nr. Purace, Marenberg, Huila; 30 Mar 1976; leg. W.D. Hamilton; coll. BMNH; Zorotypus juninensis Engel, 2000, syn. nov. - Holotype: Peru · 1 apterous ♀; Agueas Mellizas, Estancia Naranjal San Ramon, Dep. Junin; 1 500 m; July 1965; leg. P. & B. Wygodzinsky; coll. AMNH: IZS00343397; Paratypes: 1 apterous ♀; 1 apterous ♂: same locality data as in Holotype (AMNH: IZS00343398).

Diagnosis.

Dark-brownish black Zoraptera, with anterior regions of abdominal tergites darker than posterior regions; antennal segment nine, and apex of segment eight pale. Body length ranges from 2.9 to 3.6 mm; antennal length ranges from 1.45 to 1.63 mm. Ventral side of metafemur with row of 8 to 10 thickened setae situated in the distal two-thirds of the femur; proximal third with several (5-8) slender setae (Fig. 1A, B ). Metafemur of females with the same arrangement of setae with less pronounced thickening. Abdominal tergites T5-T8 (Fig. 2A-D ) each with a single posterior row of 10 to 14 setae and 1 or 2 more anterior setae near each lateral border. Abdominal tergite T9 with group of 6 to 8 thickened setae on each side of the midline (Fig. 2A, D ). Tergite T10+11 membranous medially (Fig. 2A, C, D ), with about 20 short setae each side of the midline and a median insert bearing a short dorsally curved extension (mating hook). Cerci (Fig. 2A-D ) slightly longer than wide, tapered, with several long apical setae. Male genitalia symmetrical (Fig. 2E, F ). Basal plate flat, 0.5 mm long, sclerotized, with an anterior conical process, and posteriorly bifurcated; flagellum sclerotized, coiled, and 1.4 mm long.

Taxonomic comments.

The studied paratype male of Z. juninensis fully agrees with the holotype male of C. hamiltoni in external characters as well as in morphology of male genital armature. The spiral of the coiled flagellum is more open in preparate of Z. juninensis (Fig. 2E ) than in C. hamiltoni (Fig. 2F ); the less open flagellum of C. hamiltoni is probably an artefact of preparation. We measured the lengths of both flagella, and these were nearly identical (1.382 mm for Z. juninensis vs. 1.375 mm for C. hamiltoni ).

Centrozoros hamiltoni (New, 1978) is morphologically similar to C. manni (Caudell, 1923), C. neotropicus (Silvestri, 1916), C. cramptoni (Gurney, 1938), and C. gurneyi (Choe, 1989). C. manni is known only from female specimens. Engel and Grimaldi (2000) reported that C. hamiltoni (sensu this study) differed from C. manni in lacking a medial cleft on the apex of S8 in females and in its broadly separated basal processes on S9 in females, its S9 setation pattern on females, its medial field of minute spicules on the cerci, and its long, sinuous setae on the cerci. Centrozoros neotropicus (Silvestri, 1916) is another species similar to C. hamiltoni in external morphology, including the setation and arrangement of abdominal tergites/sternites. This species is known only from Costa Rica ( Silvestri 1916; Gurney 1938; Choe 1992; Kočárek et al. 2020), and it differs from C. hamiltoni in the arrangement of its metafemur setae (Fig. 1C, D ), which are composed of 5-9 thick setae of similar length (as noted earlier, C. hamiltoni has 8-10 thickened setae in the distal two-thirds of its femurs and 5-8 slender and shorter setae in the basal one-third of its femurs). The morphology of only females has been described in literature ( Silvestri 1916). We also studied the single male specimen of C. neotropicus deposited in the ZMH collections, but the permanent slide did not enable the detailed study of the copulatory organs necessary for clear species diagnosis. The validity of this species was verified molecularly ( Kočárek et al. 2020), but the diagnosis should be augmented by the description of male genitalia after the next specimens of males are found. Centrozoros cramptoni and C. gurneyi seem to be most closely related to C. hamiltoni based on their similar morphology of male genital armature. The proximal part of the basal plate of both species has a conical shape as does the plate in C. hamiltoni , but the corners of the bifurcated basal part are continually divergent in C. cramptoni (Gurney, 1938) in contrast to the convergent tips of corners in C. hamiltoni (Fig. 2E, F ); in the case of C. gurneyi , the bifurcated part regularly narrows towards the end, and the tips of the arms are narrower than the midregion of the basal plate ( Choe 1989). These three species also differ in the arrangement of metafemur setae and in the setation of abdominal tergite T9. Like sternite 8 in C. manni females, sternite S8 in the females of C. gurneyi have an emarginated tip (in contrast to C. hamiltoni and C. neotropicus with not emarginated distal margin of S8). Relative to C. hamiltoni , C. gurneyi and C. cramptoni , the other two Centrozoros species ( C. snyderi (Caudell, 1920) and C. mexicanus (Bolivar y Pieltain, 1940)) differ substantially in the morphology of male genitals in that they have a broad rather than a conical basal plate ( Gurney 1938; Bolivar y Pieltain 1940). Centrozoros snyderi and C. mexicanus appear to be closely related.

Molecular identification.

For unequivocal species identification, we attempted to obtain a DNA barcode from the Z. juninensis paratype (AMNH: IZS00343398). For DNA isolation, we used the QIAamp DNA micro kit designed for a small amount of tissue. According to the voucher, the specimen was preserved in pure ethanol and was almost 60 years old when we examined it. Although we have attempted to amplify the DNA several times, our attempts to obtain partial sequences of 16S RNA, COI, and 18S RNA have failed.

Distribution.

Centrozoros hamiltoni (New, 1978) was originally reported from Colombia ( New 1978), and was additionally documented from Colombia by Villamizar and González-Montana (2018). The morphological characters of a single male from Barbados mentioned by New (1978) were similar to all of the characters described for C. hamiltoni except that basal plate was a little narrower and shorter on the Barbados male than on the C. hamiltoni males; Matsumura et al. (2020) described a specimen from Ecuador that they tentatively identified as C. hamiltoni . Zorotypus juninensis Engel, 2000 has been described from Junin Province in Peru ( Engel and Grimaldi 2000), and was later reported from Peru by Matsumura et al. (2020). Published records indicate that the distribution of C. hamiltoni includes western Amazonia (Colombia, Peru, Ecuador), but the record from Barbados suggests a potentially wider distribution in the Neotropical region. Further studies are needed to clarify the distribution of C. hamiltoni .

Figures

Figure 1. A. Hind legs of the paratype male of Zorotypus juninensis Engel, 2000 syn. nov.; B. Hind leg of the holotype male of Centrozoros hamiltoni (New, 1978); C. Hind leg of a male of Centrozoros neotropicus (Silvestri, 1916); D. Hind leg of a female of C. neotropicus. Scale bars: 0.5 mm.

Figure 2. Centrozoros hamiltoni (New, 1978). A, B, C, E. The paratype male of Zorotypus juninensis Engel, 2000, syn. nov.; D, F. The holotype male of C. hamiltoni. A. Tip of the male abdomen of C. hamiltoni, dorsal view; B. Tip of the male abdomen of C. hamiltoni, ventral view; C. Tip of the male abdomen of C. hamiltoni, ventro-lateral view; D. Tip of the male abdomen of C. hamiltoni, dorsal view; E. Male genital armature of the Z. juninensis paratype; F. Male genital armature of the C. hamiltoni holotype. Scale bars: 0.2 mm.