Trejo-Palacios, Susana Janeth ¹ ; Toledo-Hernández, Víctor Hugo ² ; Paredes-León, Ricardo ³ ; Khaustov, Alexander A. ⁴ and Corona-López, Angélica María ⁵

¹Centro de Investigación en Biodiversidad y Conservación (CIβγC), Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209, Cuernavaca, Morelos, Mexico.
²Colección de Insectos de la Universidad de Morelos (CIUM), Centro de Investigación en Biodiversidad y Conservación (CIβγC), Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209, Cuernavaca, Morelos, Mexico.
³Colección Nacional de Ácaros, Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Coyoacán, C.P. 04510, Ciudad de México, Mexico.
⁴X-BIO Institute, Tyumen State University, Tyumen, Russia.
⁵✉ Colección de Insectos de la Universidad de Morelos (CIUM), Centro de Investigación en Biodiversidad y Conservación (CIβγC), Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209, Cuernavaca, Morelos, Mexico.

2024 - Volume: 64 Issue: 2 pages: 335-343

ZooBank LSID: 90BA285B-FE52-4C14-855E-9C7C507BBD91

Original research

Keywords

Abstract

Introduction

Mites of the family Acarophenacidae Cross, 1965 include species with phoretic adult females and parasitoids of insect's eggs, and pre-phoretic attendance (Walter & Seeman 2017; Khaustov & Abramov 2019, 2021). The family comprises eight genera and about 40 described species (Khaustov & Abramov 2021; Khaustov et al. 2021). The genus Paracarophenax was established by Cross in 1965 with the description of the species Paracarophenax dybasi Cross, 1965, type species of the genus, and the taxonomic transference of Acarophenax bambergensis Krczal, 1959 to this new genus. Subsequently, six more species were described associated with decomposing organic matter and beetles of the families Cerambycidae, Curculionidae, Erotylidae, Mycetophagidae and Nitidulidae, and characterized by the presence of the prodorsum with two pairs of setae, the dorsal stigmatal openings with membranous atria, tibia and tarsus I fused, tarsi I-IV with claws and the absence of U-shaped apodeme in gnathosoma (Krczal 1959; Cross 1965; Mahunka 1975; Mahunka & Rack 1977; Khaustov 1999; Katlav et al. 2015; Walter & Seeman 2017; Khaustov & Abramov 2018; Xu et al. 2018; Khaustov et al. 2021). In addition, Cross (1965) refers to an undescribed species of Paracarophenax collected from an unidentified Cerambycidae from Panama, which to our knowledge has never been described. Before this study, there are no records of this genus and the family Acarophenacidae from Mexico.

In this study, following a taxonomic study of mites associated with Coleoptera deposited in Colección de Insectos de la Universidad de Morelos (CIUM), Morelos, Mexico, a new species is described based on phoretic females associated with Cerambycidae collected from Mexico. We also provide an updated key of the species of Paracarophenax.

Material and methods

Specimens of Cerambycidae family deposited in the CIUM from localities in Mexico were examined under a stereomicroscope Nikon C-LEDS (Tokyo, Japan) to collect phoretic mites. The mites were found ventrally between coxae I and II of the hosts, and were preserved in 70% ethanol for morphological identification, and were slide-mounted in Hoyer's medium following the protocol described by Walter & Krantz (2009) for their taxonomic identification according to the keys presented by Walter & Seeman (2017), Xu et al. (2018), and Khaustov et al. (2021). The mites were measured and microphotographed with a Nikon Eclipse 80i optical microscope (Nikon Japan Y-TV55), equipped with a Nikon DS-Ri2 camera. Measurement data are given in micrometers (μm) for the holotype and the ranges of paratypes are in parentheses. Drawings were made by superposition of vector art placed on the microphotographs in Adobe Illustrator CC 2017 software (Adobe Systems Inc., San Jose, California). The terminology follows the adaptation of Katlav et al. (2015) and Walter & Seeman (2017) from Lindquist (1986). Finally, one individual was used for scanning electron microscopy (SEM) study at Laboratorio de Microscopia Electrónica, Instituto de Biología (IB) of the Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.

Results

Systematics

Family Acarophenacidae Cross, 1965

Genus Paracarophenax Cross, 1965

Type species: Paracarophenax dybasi Cross, 1965

Paracarophenax cerambycinus Trejo-Palacios n. sp.

ZOOBANK: 022F2656-EA10-4C5B-90F9-7ABE0861E9FD

(Figures 1–3)

Description

Phoretic female — idiosoma length 212 (183–257), width 104 (90–151).

Gnathosoma — (Figures 1A, 1B, 3D). Rounded, partially concealed dorsally by prodorsum, posterior edge distinguishable ventrally from idiosoma; posterior ventral region with membranous-striate areas; palps fused with gnathosomal capsule; cheliceral stylets strong, and one pair of postpalpal setae (pp) 3 (3–6). Pharynx enlarged and almost elliptical.

Idiosomal dorsum — (Figures 1A, 3A). Ovate; prodorsal shield and tergites C, D, EF, H punctate. Prodorsal shield trapezoidal with two pairs of external vertical and external scapular setae (v₂ and sc₂ ) thickened and barbed. Setae v₂ longer than sc₂ . Stigmata on prodorsal projection, tracheal trunks with a brush-like atrium. Pits of internal scapular setae (sc₁ ) situated anterolaterally to bases of setae v₂ . Tergite C with two pairs of setae (c₁ and c₂ ). Tergite D with one pair of setae d; tergite EF with two pairs of setae (e and f); tergite H with two pairs of setae (h₁ and h₂ ). One pair of crescent-shaped ornamentation located near posterior margin of tergite C, one pair near posterior margin of tergite D, and one pair near posterior margin of prodorsal shield. Cupules small, oval; cupules ia, im and ih situated anterior and lateral to bases of setae d, e and h₂ respectively. All setae of tergites C, D, EF and H with short barbs and shorter and slender than prodorsal setae; setae v₂ about two times longer than setae sc₂; setae e slightly longer than f; setae h₂ located far from h₁, and the distance between setae e and f subequal to distance between setae h₁ and h₂. Lengths of dorsal setae: v₂ 28 (19–28), sc₂ 17 (13–20), c₁ 11 (10–14), c₂ 15 (12–18), d 14 (12–17), e 14 (12–15), f 11 (9–13), h₁ 13 (11–14), h₂ 19 (15–25). Distances between setae: v₂–v₂ 32 (26–35), sc₂–sc₂ 81 (69–85), v₂–sc₂ 24 (21–26), c₁–c₁ 46 (35–55), c₂–c₂ 97 (86–113), c₁–c₂ 28 (22–31), d–d 73 (68–90), f–f 27 (19–29), e–f 13 (14–21), h₁–h₁ 13 (12–20), h₂–h₂ 42 (35–50), h₁–h₂ 15 (11–18).

Idiosomal venter — (Figures 1B, 3B). Ventral plates punctate. All coxal setae of ventral plates (1a, 2a, 3a, 3c, 4a, 4b and 4c) thin and smooth. Apodemes 1 (ap1) fused, apodemes 2 (ap2) and sejugal apodeme (apsej) joined with prosternal apodeme (appr); apodeme 3 (ap3) restricted proximal femur III, apodemes 4 (ap4) well developed. Tegula well developed in the posterior edge of poststernal plate. Aggenital plate without setae ag. Plate PS with one pair of pseudanal setae ps weakly barbed and thicker than other ventral setae. Lengths of ventral setae: 1a 7 (7–9), 2a 11 (8–14), 3a 13 (9–21), 3c 13 (9–18), 4a 12 (8–19), 4b 9 (6–14), 4c 10 (10–13), ps 8 (8–10). Distances between setae: 1a–1a 40 (40–51), 2a–2a 38 (36–48), 3a–3a 28 (25–40), 4a–4a 20 (15–27), 4b–4b 35 (25–42), 4c–4c 55 (42–66).

Legs — (Figures 2A–2D, 3C–3E). Lengths of legs I–IV: 63 (58–80), 62 (58–72), 81 (67–90), 79 (69–93). Tibiotarsus I length 31 (26–35), width 22 (16–22). Leg I — (Figures 2A, 3C). Setal formula Tr1–Fe3–Ge4–TiTa17(2). Trochanter with seta v′ tiny, slender and smooth. Femur with seta l′ spatulate and slightly thickened, seta v″ slender and weakly barbed, seta d thickened and serrate. Genu with setae l′, l″, v′ and v″ slender and weakly barbed. Tibiotarsus with tarsal-claw complex, solenidion φ 9 (9–11) and solenidion ω 9 (7–10), seta d attenuated, whip-like and with short barbs, seta v″ slender, smooth and whip-like, seta k weakly barbed and thickened in the middle part, setae pv″ and p″ pointed, seta ft″ attenuated, pl′ elongated and attenuated, l′ weakly barbed, setae v′, l″, pl″, pv′, s, p′, tc′, ft′ and tc″ setiforms and smooth. Leg II — (Figure 2B, 3D). Setal formula Tr1–Fe3–Ge1–Ti4(1)–Ta6(1). Trochanter with seta v′ tiny and slender. Femur with setae l″, v″ and d slender and smooth. Genu with seta v′ spiniform. Tibia with solenidion φ 4 (4–5); setae d, v′ and l′ weakly barbed, elongated and attenuated, seta v″ spiniform. Tarsus with two simple claws and empodium lobed similar to legs III and IV, solenidion ω 5 (3–5), setae pl″ and pv″ spiniform, seta pv′ pointed, seta tc″ elongated and attenuated, setae u′ and u″ slender. Leg III — (Figure 2C–3E). Setal formula: Tr1–Fe1–Ge1–Ti4–Ta6. Trochanter, femur and genu each one with one seta v′ slender and pointed. Tibia with seta d weakly barbed, setae v′, v″ and l′ slender and attenuated. Tarsus with seta tc″ attenuated and whip-like, setae u´ and u″ slender, seta pv″ spiniform, seta pl″ and pv′ pointed. Leg IV — (Figure 2D). Setal formula: Tr1–Fe0–Ge1–Ti4–Ta6. Trochanter with seta v′ slender and pointed. Femur without setae. Genu with seta v′ slender and pointed. Tibia with setae d weakly barbed, setae v′, v″ and l′ slender and attenuated. Tarsus with seta tc″ attenuated and whip-like, seta pv″ spiniform, seta pl″ pointed, setae pv′, u′, u″ slender.

Other developmental stages — unknown.

Type material

Holotype (slide number CNAC012477) — Female, from Mexico, Chiapas, Ocozocoautla de Espinosa (16°53′31.5″ N, 93°27′09.5″ W, 956 m a.s.l.), ex. Atrypanius implexus Erichson, 1847.

Paratypes (n= 17; CNAC012478– CNAC012494) — Six females, same data as holotype. Five females from Mexico, Chiapas, Ocozocoautla de Espinosa (16°53′06.4″ N, 93°27′29.4″ W, 934 m a.s.l.; 16°53′31.5″ N, 93°27′09.5″ W, 956 m a.s.l.), ex. Thryallis leucophaeus (White, 1855). One female from Mexico, Tabasco, Teapa (17°32′11″ N, 92°54′45″ W, 158 m a.s.l.), ex. Platyarthron bilineatum Guérin-Méneville, 1844. Five females from Tabasco, Teapa (17°31′42″ N, 92°55′44″ W, 90 m a.s.l.), ex. Taeniotes scalatus (Gmelin, 1790).

Type deposition

The type series is deposited in the Colección Nacional de Ácaros (CNAC), Instituto de Biología (IB) of the Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.

Differential diagnosis

Paracarophenax cerambycinus n. sp. is very close to P. scolyti Khaustov, 1999 and P. alternatus Xu & Zhang, 2018. The new species is similar to P. scolyti by presence of one seta on femur III, setae e slightly longer than f and the distance between setae e and f slightly longer or equal to the distance between setae h₁ and h₂ but differs by the presence of one spiniform seta on genu II. The last character is also present in P. alternatus, and both species are associated with Cerambycidae, however, P. cerambycinus n. sp. differs from P. alternatus in having femur III with one setae, and the seta l′ on femur I spatulate and slightly thickened instead two setae on femur III, and seta l′ setiform. Also, the new species differs of P. alternatus in having setae e slightly longer than f, setae h₂ located far to h₁, and the distance between setae e and f slightly longer or equal to the distance between setae h₁ and h₂, rather than setae f longer than e, setae h₂ located very close to h₁, and the distance between setae h₁ and h₂ is about one fifth of the distance between setae e and f in P. alternatus.

Etymology

The new species name refers to Cerambycidae family, host of the new species.

Key to species of Paracarophenax (after Xu et al. 2018 with modifications)

1. Tergite EF with one pair of setae f (setae e absent); setae ps absent; trochanter II without setae
...... 2

— Tergite EF with two pairs of setae e and f; setae ps present; trochanter II with seta v′
...... 4

2. Aggenital setae ag present, trochanter I with seta v′
...... P. triplaxophilus Khaustov & Abramov, 2018 – Russia

— Aggenital setae ag absent, trochanter I without setae
...... 3

3. Tracheal atria bulbous, narrowing distally; sejugal apodeme fully developed; apodemes I moderately well developed
...... P. paucisetosus Mahunka & Rack, 1977 – Hungary

— Tracheal atria cylindrical, not narrowing distally; sejugal apodeme weakly developed medially; apodemes I weakly developed or obsolete
...... P. myzognathus Walter & Seeman, 2017 – Canada

4. Opisthogaster without setae ag absent; tegula present
...... 5

— Opisthogaster with one pair of setae ag present; tegula absent
...... 8

5. Setae h₂ present; tracheae with atrium terminating in brush-like extensions
...... 6

— Setae h₂ absent; tracheae without obvious atrium extensions
...... P. undosus Mahunka, 1975 – New Guinea

6. Genu II with one setiform seta
...... P. scolyti Khaustov, 1999 – Crimea

— Genu II with one spiniform seta
...... 7

7. Femur III with two setae; setae f about twice longer than e; setae h₂ located very close to h₁, and about one fifth of the distance between setae e and f
...... P. alternatus Xu & Zhang, 2018 – China

— Femur III with one seta; setae e slightly longer than f; setae h₂ located far to h₁, and the distance between setae e and f about equal to the distance between setae h₁ and h₂
...... P. cerambycinus n. sp. – Mexico

8. Prosternal and poststernal apodemes absent; setae h₂ as long as h₁
...... P. dybasi Cross, 1965 – USA

— Prosternal apodeme present; poststernal apodeme present as remnant; setae h₂ about twice as long as h₁
...... P. bambergensis (Krczal, 1959) – Germany, Russia

Discussion

The host range of Paracarophenax is wide, mostly there are associations with beetles, and members of the family Cerambycidae appear to be potential hosts of these mites. The first record of the genus on cerambycid beetles was recorded in China (Xu et al. 2018), and in the present study Paracarophenax has been found associated with four new host species belonging to Cerambycidae (Table 1).

Paracarophenax is a genus distributed in America, Asia, Europe and Oceania. In the American continent species of this genus were described from Canada, USA and now from Mexico (Table 1). It also is the first record of the family Acarophenacidae from the country. The new species, P. cerambycinus n. sp. is the 9^th species assigned to this genus which contributes to expanding the range of geographical distribution of Paracarophenax in American continent with the first record for the Neotropical Region. Taking into account the current records of the genus in southern Mexico, and the possible record of Paracarophenax in South America (Cross 1965), it is possible to assume a wide distribution of this genus in other areas of the Neotropic, therefore it is imperative to continue studying these associations between Acari and Coleoptera in unexplored hosts and habitats.

Acknowledgments

We are very grateful to the team of the Colección de Insectos de la Universidad de Morelos (CIUM) for the collection of biological material for this study. Thanks go to Dr. Juan M. Caspeta for providing access to the microscopy equipment. We are grateful to Berenit Mendoza-Garfias for her assistance in processing samples for SEM photographs (IB-UNAM). Trejo-Palacios thanks Consejo Nacional de Ciencia y Tecnología (CONACyT) for the doctoral study scholarship (812868). This study was completed as part of Trejo-Palacios's doctoral dissertation in the Doctorado en Ciencias Naturales-UAEM. We would like to express our acknowledge and appreciation to anonymous reviewers and Editor for their valuable comments and suggestions to the manuscript.

References

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