1✉ Department of Soil, Plant and Food Sciences (Di.S.S.P.A.), University of Bari Aldo Moro, via Amendola, 165/a, Bari, 70126, Italy & World Biodiversity Association Onlus c/o Museo Civico di Storia Naturale, Lungadige Porta Vittoria, 9, 37129 Verona, Italy.
2Unidade Laboratorial de Referência em Biologia Molecular Aplicada, Instituto Biológico, Av. Conselheiro Rodrigues Alves, 1252 - Vila Mariana, São Paulo - SP, 04014-002, Brazil.
3Animal Plant Health Inspection Service, APHIS-USDA, Humble, Texas, 77338, USA.
4Systematic Entomology Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, Maryland, 20705, USA.
2021 - Volume: 61 Issue: 4 pages: 978-995https://doi.org/10.24349/opjx-3ucc
Obligatory phytophagous mites belonging to the family Tenuipalpidae Berlese, 1913 (Castro et al. 2015; Beard et al. 2018), are cosmopolitan in distribution, containing several economically important pest species. Within the family, Cenopalpus is an important genus with 71 described species (Castro et al. 2020). In the last two decades, researchers reported new records and species of this genus in several countries, including Bulgaria (Trencheva and Trenchev 2018), Georgia (Arabuli and Kvavadze 2013), Greece (Hatzinikolis et al. 2001), Hungary (Ueckermann and Ripka 2016; Kontschán et al. 2020), India (Mitra et al. 2018), Iran (Rahmani et al. 2008; Khanjani et al. 2012; Ardali et al. 2014), Japan (Negm et al. 2020), Pakistan (Hasan et al. 2004; Iqbal et al. 2007), Syria (Barbar 2016; Barbar 2018; Zeity and Srinivasa 2019), Turkey (Sağlam and Cobanoğlu 2010; Cobanoğlu et al. 2016; Cobanoğlu et al. 2019) and the United States (Bajwa et al. 2001). The increasing discoveries of Cenopalpus spp. indicates an ever-growing risk of invasion in a global economy. Despite multiple surveys for flat mites made by Baker and colleagues in Mexico, no records of the genus Cenopalpus were cited until now (Baker et al. 1975; Tuttle et al. 1976; Baker and Tuttle 1987). The study of the geographical distribution of these mites along with their host association, damage and potential pathogen transmission requires careful examination for the formation of future control plans (Gerson 2008; Farzan et al. 2013; Rodrigues and Childers 2013; Alberti and Kitajima 2014). This paper aims to report new findings of Cenopalpus officinalis Papaioannou-Souliotis, 1986 from Israel, Italy and Mexico and revise the species description based on new morphological characters observed by cryo-scanning electron microscopy.
In 2019, flat mites were collected from twigs and leaves of Rosmarinus officinalis L. (Lamiaceae) in Apulia-District (Southern-Italy). The samples were placed inside a polyethylene bag with a paper towel and stored at reduced temperatures (about +4oC). The coordinates were taken using Map Coordinates (version 4.8.28) and expressed in degrees, minutes, seconds.
Plant samples from Apulia were examined under an Olympus SZH10 stereomicroscope at the Department of Soil, Plant and Food Sciences (DiSSPA), University of Bari Aldo Moro. The stereomicroscope's photos were taken by a Canon Mark III camera using EOS utility 0.1.18.0. The specimens were mounted on microscope slides in Hoyer's medium (Walter and Krantz, 2009) and placed in an oven (40-50 °C) for one week. The specimens were examined and compared with material deposited at the United States National Mite Collection (USNM) using Differential Interference Contrast (DIC) and Phase Contrast microscopy. The light microscopy photographs were taken with a Zeiss Imager D1 microscope with an AxioCam ICc5 using AxionVision SE64 and optimized by Adobe Photoshop 10 version 21.0.3. Drawings were made through a camera lucida mounted on a Leica DMR microscope and were optimized by Adobe Photoshop 10 version 21.0.3. Specimens stored in 70% ethanol were used for cryo-scanning electron microscopy studies; specimen preparation followed the technique outlined by Bolton et al. (2014). The specimens were analyzed by cryo-scanning electron microscopy following, without any modifications, the methodology completely described in Beard et al. 2015.
All measurements are presented in micrometers (µm), followed by the measurements for the paratype in square brackets reported in the re-description (Hatzinikolis et al. 1999). Setae were measured from the centre of the setal base to the tip of the setal shaft; distances between setae were measured as the distance between the centre of the bases of the setae. Body size was measured as: v2-h1 (= length excluding gnathosoma), palp tarsus-h1 (= length including gnathosoma), propodosoma width between v2-sc1 and between sc1-sc2, opisthosoma width just posterior to leg IV.
Body chaetotaxy follows Grandjean (1939) and Lindquist (1985). Leg chaetotaxy is adapted from Lindquist (1985), Quiros-Gonzalez (1985) and Kane (2003). Leg setal formulas are written as the total number of tactile setae followed by the number of solenidia in parentheses. Legs were measured from the posterior margin of the coxa to the distal end of the claws. Identification was carried out using the original species description (Papaioannou-Souliotis 1986). The terminology follows Baker and Tuttle (1987), Mesa et al. (2009) and Beard et al. (2012, 2015, 2018).
The slide mounted specimens are deposited at the Entomological and Zoological Section, Department of Soil, Plant and Food Sciences (DiSSPA), University of Bari Aldo Moro, Italy (UNIBA) and at the United States National Insect & Mite Collection Smithsonian Institution, located in the Systematic Entomology Laboratory (SEL), USDA, Beltsville, Maryland, USA (USNM).
Six dorsolateral setae on opisthosoma (c3, d3, e3, f3, h2, h1). Palps four segmented. Setal formula: 0-1-2-2: palp trochanter without setae, palp femur with 1 dorsal seta, palp genu-tibia with 2 setae and palp tarsus with 2 sensory setae. Leg setal formula (coxae to tarsi): I 2-1-4-3-5-8(1ω), II 2-1-4-3-5-8(1ω), III 1-2-2-1-3-5, IV 1-1-1-0-3-5. Leg chaetotaxy as follows: coxae I-II each with two setae (1b, 1c and 2b, 2c respectively); coxae III-IV each with one seta (3b and 4b). Trochanters I-II-IV each with one seta (v′); trochanter III with two setae (l′, v′). Femora I-II with four setae (d, l′, v′, bv″); femur III with two setae (d, ev′); femur IV with one seta (ev′). Genua I-II with three setae (d, l′, l″); genu III with one seta (l′); genu IV without setae. Tibia I-II with five setae (d, v′, v″, l′, l″); tibia III-IV with three setae (d, v′, v″). Tarsi I-II with eight setae and each with one long and tapering solenidion; tarsi III-IV with five setae (ft′, tc′, tc″, u′, u″). Ventral plate with two setae (ag-ag); genital plate with 2 pairs of setae (g1 and g2); anal plate with 2 pairs of setae (ps1 and ps2).
As per C. pterinus species group, in addition to the following. Color in life red with a presence of dark circular spots in the middle of opisthosoma. Body ovate to elliptical (sensu Beentje 2010), wider posteriorly and narrower anteriorly. Anterior margin of propodosoma always smooth, partly reticulate with elongate cells. Cuticle of propodosoma with strong, broad polygonal and weak areolae medially placed. Sublateral cuticle of propodosoma with reticulation forming large cells posteriorly. Dorsal opisthosoma completely reticulate: dorsocentral, from c1-c1 to the end of e1-e1 with reticulation forming large polygonal to elongated cells. Sublateral cuticle of opisthosoma with polygonal, vertical and elongate cells. Metapodosoma almost smooth, with weak transverse striae medially between coxae III. Ventral reticulation between coxae IV can vary from polygonal to elongate (almost smooth) cells. Ventral plate with small, polygonal to elongate cells; genital plate with elongate to polygonal cells. Both plates developed and sclerotized, surrounded by four transverse and large bands. Propodosoma and opisthosoma with well-developed lanceolate and plumose setae.
ISRAEL: Newe Ya'ar, ex. R. officinalis L. (Lamiaceae), collector E. Recht, 30 Nov. 2016, 2 males, 2 females, deposited in USNM 2 slides.
ITALY: Ecotekne-Lecce (Southern-Italy) 40°20′14″ N 18°06′17″ E, 30 m, ex. twigs and leaves of R. officinalis L. (Lamiaceae), collector de Lillo Enrico, 5 Feb. 2019, 3 deutonymphs, 1 male, 7 females, deposited in DiSSPA (3 deutonymphs, 1 male and 2 females slides) and USNM (2 females slides and 3 females stored from Cryo-SEM); Bitetto (Southern-Italy) 41°02′24″ N 16°44′29″ E, 140 m, ex. stem and lower leaf surface of R. officinalis, collector De Giosa Marcello, 13 Sep. 2019, 2 deutonymphs, 17 females, deposited in DiSSPA (1 deutonymph and 11 females slides) and USNM (1 deutonymph and 3 females slides and 3 females stored from Cryo-SEM); Bari (Southern-Italy), intercepted at New York, leaves of R. officinalis, collected in 1962, 2 females, deposited in USNM 1 slide.
MEXICO: Mexico City, leaves of R. officinalis, intercepted at Chicago Airport (CHI036746), collector M. Krosniak, 26 Mar. 2009, 1 male, 1 female, deposited in USNM 2 slides.
Dorsum. (Figures 2a, 3a, 4) Body length 275-286  including the gnathosoma and distance between setae v2-h1 242-258  excluding gnathosoma; propodosoma width 130-143 and opisthosoma width 109-169. Dorsal setae: v2 29-44 , sc1 25-31 , sc2 38-48 , c1 34-47 , c2 36-39 , c3 37-39 , d1 42 , d3 37-45 , e1 27-28 , e3 35-37 , f3 31-33 , h2 21-26 , h1 14-18 . Distance between dorsal tubercles v2-v2 38-73, sc1-sc1 36, sc2-sc2 133, c1-c1 61, c2-c2 133, c3-c3 150, d1-d1 45, d3-d3 140, e1-e1 31, e3-e3 126, f3-f3 105, h2-h2 77, h1-h1 32.
Microplates. (Figures 5a-5b) Mostly separated individually, some fused, rounded to oblong shape.
Venter. (Figures 2b, 3b) Ventral setae: 1a 64-75, 1b 31-32, 1c 16-19, 2b 19, 2c 22-28, 3a 18-26, 3b 14-15, 4a 59, 4b 13-14, ag 16-21, g1 11-12, g2 12-15, ps2 5-6, ps3 13-15. Distance between ag-ag 24, g1-g1 11-12, g2-g2 42, ps2-ps2 19, ps3-ps3 26. Ventral setae 1a and 4a longer than others and lanceolate, smooth and fine. Ventral setae (ag-ag) more barbed than genital and anal setae (g1, g2, ps2, ps3).
Gnathosoma. (Figure 6a) Subcapitulum long, extending almost to level of distal end of femur I. Subcapitulum with two subcapitular setae m: length 11-13 , distance between tubercles m–m 27.
Palps. Setal formula for palps as in diagnosis of Cenopalpus pterinus species group. Palp tarsus with 1 solenidion (8)  and 1 eupathidia (4-5) . Femur seta mostly plumose and lanceolate; genu-tibia setae long, smooth and lanceolate.
Spermathecal apparatus. (Figures 6b, 7a-7b) The shape varies from long narrow convoluted duct, often not visible, with duct ending with a membranous, bulbous lobe or small rounded vesicle.
Legs. (Figures 8a-8d) Setal formula for legs I–IV as in species group. Length (coxae to tarsi): leg I 162-166, leg II 132-139, leg III 133-135, leg IV 148-154. Shape of setae on legs: leg I, femur barbed-lanceolate (bv″ – v′) and plumose-lanceolate (d – l′) setae; genu plumose setae (d – l′– l″); all tibia setae barbed and lanceolate (l′ – l″– v′ – v″) and plumose (d). Shape of setae on leg II, as following leg I, except v′ on femur and l″ on genu, smooth. Leg III with plumose-lanceolate femur seta (d) and smooth-lanceolate seta (ev′); seta l' on genu barbed; tibia with lanceolate and moderately serrate setae (v′ – v″), plumose seta (d). Shape of setae on leg IV as following leg III.
Dorsum. (Figures 9a, 10a) Dorsal reticulations with strong and polygonal cells medially, elongated to fused cells laterally. Body length 248  including the gnathosoma and 196  excluding gnathosoma; propodosoma width 108-116; opisthosoma width 56-101. Body: distance between setae v2-h1 196. Dorsal setae: v2 32-35, sc1 25-31, sc2 40-43, c1 28-29, c2 28-34, c3 36-48, d1 27-28, d3 36, e1 13-15, e3 39-45, f3 24-25, h2 25-29, h1 16-17. Distance between tubercles v2-v2 36, sc1-sc1 73, sc2-sc2 105, c1-c1 47, c2-c2 97, c3-c3 103, d1-d1 49, d3-d3 98, e1-e1 25, e3-e3 85, f3-f3 70, h2-h2 49, h1-h1 14.
Venter. (Figures 9b, 10b) Ventral cuticle almost smooth, covered mostly with transverse to longitudinal striae; coxal fields with weak striae. Cuticle posterior to 4a with transverse striae, widely spaced; irregular reticulation with large cells posterior to ag–ag. Ventral setae: 1a 50-61, 1b 9-20, 1c 16-19, 2b 10-22, 2c 18-20, 3a 19-25, 3b 14-19, 4a 65-75, 4b 13-16, ag 13-17, g1 9, ps1 10, ps2 32-34. Distance between ag-ag 16. Ventral setae short except 1a and 4a lanceolate and fine; 1b, 1c, 2b, 2c, 3a, 3b, 4b smooth and moderately barbed; ag, ag1, ag2, ps2 barbed; anal setae ps3 very long, lanceolate and fine.
Aedeagus. (Figures 9b, 11a-1b) Aedeagus narrow, elongate and sclerotized, ending in a rounded membranous bulb. Length: 97.
Gnathosoma. Subcapitulum not reaching distal end of femur I. Subcapitulum with two subcapitular setae m: length 5-7, distance between tubercles m–m 15.
Palps. As in female: femur with 1 dorsal seta, palp genu-tibia with 2 setae, palp tarsus with 1 solenidion (length 7) and one eupathidia. Femur seta finely serrate-barbed; genu-tibia setae smooth and lanceolate.
Legs. Similar to adult female. Length: leg I 151-152; leg II 121-134; leg III 122-124; leg IV 135-140.
Dorsum. (Figures 12a, 13a, 14a-14b) Length of the body including the gnathosoma 237-285 ; length body excluding gnathosoma 217-253 ; width propodosoma 72-103; width opisthosoma 42-102. Dorsal propodosoma reticulation absent, mostly smooth with weak striations. Dorsal opisthosoma with transverse striate medially between c3-c3 to f3-f3. Dorsal propodosoma and opisthosoma setae thin with short setules (lanceolate and finely serrate): v2, sc1, sc2, c1, c2, c3, d1, d3, e3, f3,h2; except e1 and h1 that are absent. Body: distance between setae v2-h1 199-240. Dorsal setae: v2 44-66, sc1 37-46, sc2 41-51, c1 42-71, c2 38-70, c3 42-51, d1 63-63, d3 47-73, e3 52-69, f3 42-60, h2 55-63. Distance between tubercles: v2-v2 16-40, sc1-sc1 25-64, sc2-sc2 39-103, c1-c1 35-36, c2-c2 79-89, c3-c3 95-101, d1-d1 16-20, d3-d3 88-102, e3-e3 84-95, f3-f3 74-76, h2-h2 55-55, h1-h1 21.
Venter. (Figure 13b) Cuticle mostly plicate, covered with transverse and narrow striae up to ag-ag, except coxal fields with weak striae. Ventral, genital and anal shields indistinct, with short and weak transverse-vertically striae. Ventral setae: 1a 36-67, 1b 5-14, 1c 7-12, 2b 11-16, 2c 14-20, 3a 13-14, 3b 12-15, 4a 39-40, 4b 10-13, ag 4-5, g1 3-4, ps2 5, ps3 6. Distance between ag-ag 25, g1-g1 17. Ventral setae short except for 1a and 4a which are much longer and lanceolate; ag-ag and g1-g1 more barbed than pseudoanal setae (ps2-ps3).
Gnathostoma. Subcapitulum with two subcapitular setae m: length 4-6.
Palps. (Figure 12b) Setal formula: 0-1-2-2: palp genu-tibia with 2 setae, palp tarsus with 1 solenidion and 1 short eupathidium. Femur seta finely barbed; genu-tibia setae smooth and lanceolate.
Legs. (Figures 15a-15c) Setal formula (femur to tarsi): I 4-3-5-8(1ω), II 4-3-5-8(1ω), III 2-1-3-5, IV 1-0-3-5. Length (coxae to tarsi): leg I 98-114, leg II 80-93, leg III 93-71, leg IV 91-111. Shape of setae on legs: leg II with four setae on femur, bv″ - d and l′ plumose and lanceolate, v′ smooth and lanceolate; genu with barbed and short seta (d) and shorth-smooth setae (l′ - l″); tibia setae moderately barbed and lanceolate (l′ – v′ – v″), mostly barbed and lanceolate (d), barbed and short (l″). Leg III with barbed femur seta (d) and smooth seta (ev′); seta l′ on genu short and barbed; tibia with lanceolate and moderately serrate setae (v′ – v″), short and barbed seta (d). Shape of setae on leg IV as following leg III.
Eggs (Figures 16a-16b)
Most of the eggs were grouped on lower leaf surface (near the abaxial veins) and in general on the trichome tips. This behavior may be a strategy to protect the eggs from predation. Eggs are oblong with longitudinal fine ridges (almost smooth).
The specimens of C. officinalis recovered from Israel, Italy and Mexico are in concordance with the redescription of the paratypes collected by Hatzinikolis et al. (1999), except for some minor morphological differences. The anterior margin of the female's propodosoma is smooth distally and shows polygonal cells in a more proximal area (vs. completely and strongly reticulated with polygonal cells), the palp's eupathidia is shorter than the solenidion (vs. solenidion longer than the eupathidia), the seta on palp femur is plumose and lanceolate (vs. pilose and short), the ornamentation of the genital and anal plates has cells that are polygonal to elongate (vs. only polygonal). In addition, the distal end of the spermathecal apparatus can vary: the specimens from Israel, Mexico, and some from Italy, agree with the type since the convoluted duct terminates in a bulbous lobe; however, some of the specimens from Italy differ as the distal end of the spermathecal apparatus ends in a small membranous vesicle. Considering the deutonymph, only the length of dorsocentral (e1) and dorsolateral (h1) setae appeared to be different between our specimens and the types. Indeed, in the original description given by Papaioannou-Souliotis (1986), and according with the first re-description (Hatzinikolis et al. 1999), the third pair of the dorsocentrals and the fifth pair of dorsolaterals were indicated as ''minute.'' These setae could not be discerned on their tubercles in some of our specimens, possibly because e1 and h1 are micro-setae.
Cenopalpus officinalis resembles C. pterinus (Pritchard and Baker 1958) and C. adventicius (Ueckermann and Ripka 2016); all belong to the pterinus species group (Baker et al. 1975; Hatzinikolis et al. 1999) in which setae f2 is absent. The adult females of this group share some morphological characters: six dorsolateral setae, palp genu-tibia and tarsus each with two setae and tarsus II with one very long and tapering solenidion. The similarities between these three species needs further examination. The immatures of these three species differ by the length of dorsocentral and dorsolateral setae. In the deutonymph of C. officinalis, e1 and h1 are minute/absent; C. pterinus d1, e1, e3, h1 are minute and all dorsal setae of C. adventicius are longer than those of the other two species, except d1, e1, and h1 that are minute. In addition, after studying the literature (Bytinski-Salez 1966; Hatzinikolis 1982; Papaioannou-Souliotis 1986; Hatzinikolis and Emmanouel 1987; Papaioannou-Souliotis et al. 1994; Ueckermann and Ripka 2016; Kontschán and Ripka 2017; Mesa et al. 2009; Kontschán et al. 2018), we consider that R. officinalis is a preferred host for these three closely species. Future molecular analyses are needed for understanding of the possible variation of these three species. The deutonymph setae length of these three species are probably related to biotic factors and geographical distribution. Additionally, the holotype of C. officinalis was collected in Greece on R. officinalis in 1983 and the paratypes on Cupressus sempervirens Linnaeus and some ornamental plants (Papaioannou-Souliotis 1986; Papaioannou-Souliotis et al. 1994). Hatzinikolis et al. (1999), in the first re-description of C. officinalis, reported Parthenocissus sp. as a new host plant. In Apulia territories, C. officinalis was recovered only from R. officinalis, no mites were collected from C. sempervirens. Finally, the host plant may play a significant role in the spread of C. officinalis, being a popular cuisine plant, it is moved to many parts of the world. For this reason, we encourage a greater awareness of plant movement and education to recognize the symptoms of the mite damage in this host plant. High populations of these mites can cause discoloration of the leaves (silvering to brown) and affecting the market appearance.
The authors thank Enrico de Lillo (DiSSPA–UNIBA), Gregory Evans (APHIS-USDA), Andrew Ulsamer (SEL-USDA) and Eddie Ueckermann (Agricultural Research Council, Plant Protection Research, Pretoria, Republic of South Africa) for the revision and helpful suggestions on the manuscript. To Jennifer J. Beard (Queensland Museum, Australia) Debra Creel and Lucrecia Rodriguez (SEL-USDA), Armando Rosario-Lebron (APHIS-USDA), Elizeu Castro (Universidade Estadual Paulista, São José do Rio Preto, São Paulo, Brazil), Jenő Kontschán (Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences), Ricardo Bassini-Silva (University of São Paulo, Brazil), Pasquale Trotti, Franca Todisco and Giuseppe Bari (Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro) for their help with references and technical support. To the late Dr. Gary Bauchan for the access to the electron microscopy facilities (Electron and Confocal Microscopy Unit, ARS-USDA, BARC, Beltsville, USA). To the Smithsonian Natural History Museum and National Agricultural Library (NAL-USDA), SEL-USDA for support and assistance with specimens, references and equipment. The mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the USDA; USDA is an equal opportunity provider and employer. This research was in part supported by the University of Bari Aldo Moro (Global thesis) to MDG and by the ''Fundação de Amparo à Pesquisa do Estado de São Paulo'' FAPESP proc: 2018/12252-8 to ADT.