Zoosyst. Evol. 97 (1) 2021, 273-280 | DOI 10.3897/zse.97.64766 > PENSUFT. fis Neti ae BERLIN Myrmecotypus mazaxoides sp. nov. — a new ground-dwelling, carpenter ant-resembling sac spider species from the Bolivian orocline, with indirect evidence for species-specific mimicry (Araneae, Corinnidae, Castianeirinae) Robert Perger!, Nadine Dupérré? 1 Coleccion Boliviana de Fauna, La Paz, Bolivia 2 Zoological Museum, Center of Natural History, Universitat Hamburg, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany http://zoobank.org/SEBC87BB-BD96-4E6F-B636-60429325AF21 Corresponding author: Robert Perger (robertperger@hotmail.com) Academic editor: Danilo Harms Received 22 February 2021 Accepted 13 April 2021 # Published 13 May 2021 Abstract A new ant-resembling spider species of the subfamily Castianeirinae, Myrmecotypus mazaxoides sp. nov., from the Sub-Andean area of the Bolivian orocline is described. Adults of MZ mazaxoides sp. nov. resemble the carpenter ant Camponotus cf. melanoticus Emery, 1894 and were observed on the ground of savanna-like habitats close to the entrances of formicaries of this ant. This study is the first to report a ground-dwelling species of Myrmecotypus O. Pickard-Cambridge, 1894; all the other species are arboreal. Key Words Arachnid, Bolivia, Camponotus, myrmecomorph, South America Introduction The Neotropical Castianeirinae genus Myrmecotypus O. Pickard-Cambridge, 1894 is a group of slender, fast-run- ning spiders and currently includes 13 species (World Spi- der Catalog 2021). Six species are reported from South America, of which five have been recorded from Bolivia: Myrmecotypus haddadi Perger & Rubio, 2021, M. iguazu Rubio & Arbino, 2009, M. niger Chickering, 1937, M. ru- brofemoratus Perger & Rubio, 2021, and M. tahyinandu Perger & Rubio, 2020 (World Spider Catalog 2021). Potential ant models have been proposed for six of the known 13 species of Myrmecotypus (Perger and Rubio 2020a, 2021a). Morphologically, these forms resemble specific models of the ant tribes Camponotini and Doli- choderini. Models and mimics share a moderately elon- gated, truncate forebody, short petiole and sub-globose abdomen, and were predominately observed in arboreal habitats (Perger and Rubio 2020a). Ground-dwelling Neo- tropical Castianeirinae species have only been reported from the genera Castianeira Keyserling, 1879 (Reiskind 1969, 1977) and Mazax O. P.-Cambridge, 1898 (Reiskind 1977; Rubio and Danisman 2014). In the present contri- bution, an unknown, ground-dwelling species of Myrme- cotypus from the Bolivian orocline is described, and indi- rect evidence for specific ant mimicry is presented. Material and methods Spiders and ants were collected manually from the ground and herbaceous vegetation. Photographs of live spiders and ants and their habitats were taken with a Panasonic Lumix GX-80 system camera fitted with a Panasonic H-HS3030 macro lens. Color and distribution of setae were described from photos of live specimens. Spiders were euthanized with ethyl acetate and stored in 70% ethanol. Preserved specimens were examined in 70% ethanol under a Nikon Copyright Robert Perger, Nadine Dupérré. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 274 Perger, R. & Dupérré, N.: A new ant-resembling spider from the Bolivian orocline SMZ-U dissection microscope and identified using origi- nal and re-descriptions and keys (e.g., Rubio and Arbino 2009; Leister and Miller 2014; Perger and Rubio 2021b). A Nikon Coolpix 950 digital camera attached to the mi- croscope was used to photograph all the structures to be illustrated. The digital photos were used as a template to draw the structures. Female genitalia were excised using a sharp entomological needle placed on a slide in lactic acid and observed under an AmScope XSG Series T-500 compound microscope. All measurements are expressed in millimeters and were taken using a micrometric ruler on the microscope. Photos were taken with a BK Plus Lab System by Dun, Inc. with a Canon SDS Macro camera and a Canon 65 mm lens. The descriptions refer to adult specimens. Morpho- logical terms and description formats follow the recent studies on Castianeirinae spiders (Rubio and Arbino 2009; Leister and Miller 2014; Perger and Rubio 2020a, 2021b). Body length (BL) measurement refers to the distance from the anterior margin of the carapace to the posterior margin of the opisthosoma. The cephalic width was measured at the level of the posterior eye row when viewed dorsally. The length of the dorsal and epigastric sclerite was measured without the petiole, which is sep- arated from the former both sclerites by a slight groove. The following indices (sensu Reiskind 1969) were cal- culated: a) carapace index = carapace width / carapace length ) Bolivian Tucuman forest 3 Chiquitano forest Gran Chaco forest [-) Savanna, shrubland and Cerradao L_] Anthropogenic vegetation Se A -64.00 Arachnological collections are abbreviated as follows (curators in parenthesis): CBF Coleccion Boliviana de Fauna, La Paz, Bolivia (R. Perger); ZMH = Zoological Museum Hamburg, University of Hamburg, Germany (D. Harms). Ecoregion distribution The ecoregion affinities of the species were investigat- ed by visualizing the coordinates and a shape file of the regionalization of Bolivian ecosystems by Navarro and Ferreira (2011), by using the geographic information sys- tem QGIS (version 2.14.3, http:/Awww.qgis.org/en/site/). Geographic coordinates are shown in decimal degrees with reference datum WGS84, and elevation in meters above sea level (m. a.s.1.). Ant mimicry In this study, an indirect, correlative method is employed to support mimicry, without studying the impact of receiver responses on mimic fitness. While correlations do not imply causality, correlative approaches are useful for investigating putative cases of resemblance between taxa and extrapolating the consequences of mimicry beyond a single, well-studied population (De Jager and Anderson 2019; Perger and Rubio 2020a, b, 2021a). To illustrate adaptive divergence between mimetic and non- mimetic phenotypes, we identified derived traits in the mimic that likely evolved in association with species- specific models and receivers. Figure 1. Ecoregion distribution of Myrmecotypus mazaxoides sp. nov., according to the regionalization by Navarro and Ferreira (2011); A. Bolivia; B. Sub-Andean area at the Bolivian orocline 1. Collection locality of MZ mazaxoides sp. nov., Santa Cruz de la Co- lina, Santa Cruz department; map produced with QGIS (version 2.14.3, http://www.qgis.org/en/site). zse.pensoft.net Zoosyst. Evol. 97 (1) 2021, 273-280 For the analysis of ant resemblance, we considered all ants that were collected in the surveyed location and were about the same body length as the spiders. The sim- ilarity was analyzed, based on a qualitative, descriptive assessment of integument color, shine, structure (e.g., ap- pressed, erected, short, long) and color of setae and shape of body parts (e.g., abdomen shape: fusiform or ovate; apically pointed or rounded). Taxonomy Family Corinnidae Karsch, 1880 Subfamily Castianeirinae Reiskind, 1969 Genus Myrmecotypus O. Pickard-Cambridge, 1894 Type species. Myrmecotypus fuliginosus O. Pick- ard-Cambridge, 1894 (by original designation) Diagnosis. Cephalic region wide (cephalic index range 64-89), carapace narrowed (carapace index < 60), with- out thoracic groove but with slight depression instead; PER wider than AER and almost straight to moderately recurved, AME larger than ALE, PME—PME greater than PME-PLE, PLE situated close to lateral margin of ce- phalic area; abdomen only very slightly petiolated; tibia I ventral spines paired in 2—2, 3—2, 3-3 or 44 arrange- ment; trochanter IV notch usually absent, with only a tiny one, if present (Perger and Rubio 2021b). Myrmecotypus mazaxoides sp. nov. http://zoobank.org/552663F9-8A A 0-4B31-9C75-D06AC6F4E817 Figs 2-6, 7A, B Type material. Holotype 3 and @ allotype; BOLIVIA: Santa Cruz department, Santa Cruz de la Colina, Urubo; 17.760833°S, 63.24°W, 432 m. a.s.l., 21-28 Dec. 2019, R. Perger leg.; Cerrado-like grassland in urbanization (ZMH-A0014700-14701). Paratypes: 2 4, 5 9, same data as for preceding (ZMH-A0014707) * 6 ¢, 10 2, same data as for preceding; CBF. Diagnosis. Amongst species of Myrmecotypus, an elon- gated and constricted abdomen is only found in M. mazax- oides sp. nov. (Figs 2, 3, 5) and M. /ineatus (Emerton, 1909), the latter occurring along the east coast of the Unit- ed States (Reiskind 1969). Additionally, both species share a broad carapace (carapace index ~47—52) and all eyes small and sub-equal (male of M. Jineatus not described). Females of M. mazaxoides sp. nov. can be distin- guished from those of M. Jineatus by the following char- acteristics: dorsum dark brown with an anthracite-greyish appearance in live condition (Fig. 7A, B) (in M. linea- tus, carapace yellow-orange, dorsal sclerite of abdomen yellow, posterior part of abdomen dark purple-brown with light spots), coxae II-I'V translucent white, I reddish (Figs 3B, 5) (in M. /ineatus, all coxae light), dorsal scler- ite pyriform (elliptic in M. Jineatus), tibia I with 3 pro- 275 marginal and 2 retromargial spines (tibia I spination 2—2 in M. lineatus),; chelicerae with two promarginal teeth with distal tooth reduced to small denticle (3 promarginal teeth in M. Jineatus), copulatory openings of epigyne an- terior to spermathecae (lateral in M. /ineatus). Remarks. Reiskind (1969) noted the distinctness of M. lineatus while transferring this species from Castianei- rato Myrmecotypus. The general habitus of M. mazaxoides sp. nov. resembles that of species of Mazax and possibly of some Apochinomma spp. Given that the generic tax- onomy of Castianeirinae remains uncertain and requires detailed phylogenetic work (Perger and Rubio 2020a), we follow Reiskind (1969) and include the newly described species tentatively in Myrmecotypus. The generic taxono- my and morphological affinities to species of other genera of Castianeirinae are addressed in the discussion. Description of male holotype. Body length 4.69; car- apace length 2.17, width 1.11, carapace index 51; cephalic width 0.72, cephalic index 65; sternum length 0.93, width 0.67, sternum index 72; abdomen length 2.42, maximum width anterior part 0.76, maximum width posterior part 1.04, abdominal index 43; petiole length 0.10, width 0.29; dorsal sclerite length 2.32 (width agrees with abdominal width); epigastric sclerite length 0.62, width 0.74; ventral sclerite length 0.95, width 0.51; inframamillary sclerite length 0.09, width 0.15. AER 0.47; AME-AME 0.08; AME-ALE 0.02; PER 0.60; PME-PME 0.14; PME-PLE 0.11. Carapace (Fig. 2A). Long pyriform, truncated anteri- orly, front slightly convex, cephalic area laterally some- what narrowed, carapace widest in middle, three slight concavities in posterior half, posterior margin straight. Dorsum weakly shiny, smooth, microsculpture reticulate with evenly distributed, fine pits, dark brown; short, ap- pressed, separate, white and brassy setae, simple on ce- phalic area and feathery on thoracic area (setae providing an anthracite-greyish appearance in live condition), sev- eral relatively long, forward-pointing, dark setae on front of cephalic area. Eyes. Eight sub-equal eyes formed in two rows; PER distinctly recurved; AER slightly recurved. Chelicerae. Orange-brown, shiny, with separated erect dark setae, area between retro- and promarginal rows of cheliceral teeth orange-white with dense white setae, two retromarginal teeth and two promarginal teeth, with distal tooth reduced to small denticle. Abdomen (Figs 2A, 3A). Elongated, distinctly con- stricted medially, posterior part broader than anterior part; petiole only moderately developed, very narrow medial- ly, proximal margin strongly concave; dorsal sclerite al- most completely covering abdomen dorsally and lateral- ly; ventral sclerite not reaching to level of inframamillary sclerite, latter narrow, subrectangular, broader than long. Dorsum weakly shiny, smooth, microsculpture reticulate with evenly distributed, fine pits, dark brown; covered with separate, simple, short, brassy setae, abdominal setae long, simple, not sclerotized, second pair longer than first; in constriction, distinct band of relatively long, dense feathery white setae, on anterior part of abdomen zse.pensoft.net 276 Perger, R. & Dupérré, N.: A new ant-resembling spider from the Bolivian orocline Figure 2. Myrmecotypus mazaxoides sp. nov., holotype male (ZMH-A0014700): A. Dorsal; B. Ventral. Scale bars: 0.5 mm. Please note that most setae are broken off due to storage in ethanol. Figure 3. Lateral views of Myrmecotypus mazaxoides sp. nov.: A. Holotype male (ZMH-A0014700); B. Female allotype (ZMH-A0014701). Scale bars: 0.5 mm. Please note that most setae are broken off due to storage in ethanol. similar band, less dense in the middle, on posterior part three to four indistinct bands of similar setae. Legs. Coxae II and III translucent white, trochanters If and HI dark yellow; coxae and trochanters I and IV reddish-brown; legs mostly sparsely covered with fine, golden setae, including feathery setae, dense in some areas, femora and tibia with separated, erect, long se- tae; femora I and II proximal fifths reddish, distal four- fifths laterally translucent, white and dark stripes along dorsal edges, remainder of legs I and II reddish-yellow; tibia I promarginal with 3 spines, retromarginal with 2 spines; femora and tibiae III and IV reddish-brown, dark grey stripes along dorsal sides; remainder of leg III or- ange-light brown; leg IV tarsus yellow; legs III and IV lined with short, appressed white feathery setae. zse.pensoft.net Palp. Pedipalp tibia with two distinct, long setae and several shorter setae (Fig. 4A, B), retrodistal margin with one small, obtuse tooth-like apophysis (Fig. 4D, E); maxi- mum width of tibia 96% of maximum width of bulb when viewed retrolaterally; narrow genital bulb drawn out into long neck, with long, thin, sclerotized embolus with three coils and a basal ridge (Fig. 4C); sperm ducts with two loops, both lateral and basal to embolus tube (Fig. 4A, B). Female allotype. Body length 6.23; carapace length 2.85; width 1.35; carapace index 47; cephalic width 1.00; cephalic index 74; sternum length 1.19; width 0.80; ster- num index 67. Abdomen length 3.15; maximum width anterior part 1.24; maximum width posterior part 1.45; abdominal index 46; petiole length 0.16; width 0.45; dorsal sclerite length 1.04; width 0.88; epigastric scler- ite length 0.74; width 0.92; inframamillary sclerite length 0.16; width 0.35. AER 0.59; AME-AME 0.10; AME- ALE 0.03. PER 0.80; PME-PME 0.18; PME-PLE 0.13. Lateral constriction of abdomen indistinct (Fig. 5A), length of dorsal and epigastric sclerite one-third of ab- dominal length, dorsal sclerite pyriform, laterally not completely covering abdomen, ventral sclerite absent; coxa II-IV translucent yellow-whitish. Remaining so- matic characters as in male. Epigyne (Fig. 6). Epigynal plate forming part of the epigastric sclerite. Copulatory openings situated anterior to spermathecae, pointing in anterior direction. Copulato- ry duct running from anterior median part of spermathe- cae and connecting latter at posterior margin. Spermathe- cae oval, dorsally convex, wall more sclerotized laterally, fertilization ducts at postero-lateral margin. Variation. Females (BL 6-6.5 mm) were larger than males (BL 4.8—5.2 mm). Sexual dimorphism in coxae color (coxae II-III translucent whitish in male, II-IV in female). The number of clearly distinguishable transversal bands of feathery setae on the abdomen varied between one or two in the median constriction and three or four closely before the apex. While the abdominal constriction of the male is determined by the shape of the large dorsal sclerite, it var- ied in females according to the nutritional or reproductive state and could be similarly constricted as in males. Etymology. The specific epithet, mazaxoides, is de- rived from the Castianeirinae genus “Mazax” and “oe- idés” (Greek) = resembling or looking like and refers to the general resemblance of the habitus of this species to species of Mazax. Geographical and ecological distribution. This spe- cies is only known from the type locality in the recently established urbanization of Santa Cruz de la Colina, Uru- bo, Santa Cruz department. This urbanization included empty plots with savanna grasslands, plant successions and bushes or houses with gardens. According to the ecoregion delineation by Navarro and Ferreira (2011), the forest in this area 1s considered Chiquitano forest. The urbanization was surrounded by a mosaic of forest fragments, Cerrado-like grassland and savanna. Myrme- cotypus mazaxoides sp. nov. was observed foraging on the ground of open grassland during the day, under or be- tween dense ground vegetation (Fig. 7A). Because of its Zoosyst. Evol. 97 (1) 2021, 273-280 Figure 4. Myrmecotypus mazaxoides sp. nov., palp male holotype (ZMH-A0014700), A, B. Ventral view; C. Tip embolus; D, E. Lateral view. (Em = embolus; RTA = retrolateral tibial apophysis). Figure 5. Myrmecotypus mazaxoides sp. nov., allotype female (ZMH-A0014701): A. Dorsal; B. Ventral. Scale bars: 0.5 mm. Please note that most setae are broken off due to storage in ethanol. presence in open habitats, it is likely that the species also occurs in similar habitats in the Gran Chaco area in south- ern Bolivia, Paraguay and northern Argentina. Despite high sampling effort in several Bolivian forest ecoregions (Perger and Perger 2017; Perger and Rubio 2018, 2020a, b), the new species was not observed in forest habitats. Myrmecotypus mazaxoides sp. nov. co-occurred with four different species of Castianeira (not determined) in the same habitat, three of which were commonly ob- served and had a dark body (blackish or black with grey) and red legs. A single male of Mazax cf. ramirezi Rubio & Danisman, 2014, was collected as well, among individ- uals of MM. mazaxoides sp. nov. Ant mimicry. Eleven ant species with a similar or larger body length than adults of 4 mazaxoides sp. nov. (BL 4.8-6.5 mm) were found in the investigated plots. However, all individuals of the new species were collect- Figure 6. Myrmecotypus mazaxoides sp. nov., epigyne female allotype (ZMH-A0014701), A. Ventral view; B. Internal genitalia cleared, dorsal view. (CO = copulatory opening; CD = copulatory duct; ST = spermatheca; FD = fertilization duct). zse.pensoft.net 278 Perger, R. & Dupérré, N.: A new ant-resembling spider from the Bolivian orocline Figure 7. Life habitus and morphological resemblance between spider and possible ant model: Myrmecotypus mazaxoides sp. nov., males: A. In natural habitat; B. On white background. Camponotus cf. melanoticus Emery, 1894 (minor workers): C. In natural habitat; D. On white background. ed close to the entrance of subterranean formicaries of Camponotus cf. melanoticus Emery, 1894. Myrmecoty- pus mazaxoides sp. nov. and C. cf. melanoticus shared an elongated, sub-oval abdomen, a weakly shiny, dark brown integument with anthracite tinge, fine brassy pubescence and sparse white setae on the posterior abdomen, and completely red legs (Fig. 7). The reddish pedipalps of the spider resembled the reddish mandibles of the ants. Ma- jor workers of C. cf. melanoticus were unlikely models, as they were larger and had proportionally larger heads. The body length of adults of 4 mazaxoides sp. nov. (BL 4 8-6.5 mm) was similar to the range of minor workers (BL 5.8—6.2 mm) of C. cf. melanoticus. No other ant species with a weakly shiny, greyish body, short brassy pubescence or completely red legs was ob- served in the studied area. Two additional ant species had an oval abdomen, but one of those species had a brown pronotum and a black, shiny abdomen (Camponotus cf. fastigatus Roger, 1863), and the other species a reddish forebody and abdomen with golden pubescence (Cam- ponotus cf. blandus Smith, F., 1858). zse.pensoft.net When the first author approached the individuals of M. mazaxoides sp. nov., they were hiding under ground vegetation (e.g., Fig. 7A). In contrast, individuals of C. cf. melanoticus started to run fast and erratically after coming into contact with the hand of the main author, and many approached and some successfully adminis- tered a bite. The ants also behaved aggressively towards individuals of MM. mazaxoides sp. nov. that came to close to the entrance of the formicaries, attacking and biting the spiders. The spiders rapidly retreated after such ag- onistic behavior. For about six months, the colony of C. cf. melanoticus was expelled by a colony of the larger Camponotus renggeri Emery, 1894, which was attracted by mealybugs on a near- by stand of introduced Croton plants. During the absence of C. cf. melanoticus, no individuals of M. mazaxoides sp. nov. were observed, despite a similar sampling effort. Af- ter the removal of the mealybugs by the main author, C. renggeri stayed away and the site was re-colonized by C. cf. melanoticus and M. mazaxoides sp. nov., indicating a strong mimetic relationship between these ants and spiders. Zoosyst. Evol. 97 (1) 2021, 273-280 Discussion Possible intergeneric relationships Rubio and Arbino (2009) referred to the resemblance be- tween Myrmecotypus and Apochinomma. While the Afro- tropical species of Apochinomma have been revised by Haddad (2013), the generic placement of the Neotropical congeners remains uncertain. Rubio and Arbino (2009) questioned whether Apochinomma is present in the Neo- tropical region, suggesting that some Neotropical species of this genus may belong to Myrmecotypus. From the Neotropics, nine species of Apochinomma have been de- scribed, eight from Brazil and one from Guyana (World Spider Catalog 2021). Apochinomma acanthaspis Simon, 1896 (BL female type 5 mm), A. armatum Mello-Leitao, 1922 (BL female type 5 mm), A. constrictum Simon, 1896 (BL female type 5.2 mm) and A. pyriforme (Keyserling, 1891) (BL female type 6.7 mm) have an elongated, con- stricted abdomen. However, A. acanthaspis and A. arma- tum have the second pair of setae on the dorsal abdominal sclerite sclerotized to spines, indicating that both may be- long to Mazax (Perger and Rubio 2020a). Apochinomma constrictum has all coxae red-brown and lacks transverse bands of setae and A. pyriforme can be distinguished by the AME larger than the other eyes, the PER straight, and comparably narrow (typical arrangement for Castianei- ra), and the femora II-IV yellow (see Keyserling 1891). Generic placement Because of the elongated, constricted abdomen, the general habitus of M. mazaxoides sp. nov. resembles that of Mazax species. Myrmecotypus and Mazax share a moderate to extremely weak thoracic groove and the AER straight to (moderately) recurved. Additionally, there is an overlap of the number of the tibia I ventral spines (Myrmecotypus: 2-2, 3-2, 3-3 or 44; Mazax: 3-3, 4-4, 5—5, or 6-6). Both genera differ concerning their cephalic index (in Mazax the thoracic part is wider, resulting in a cephalic index of 53-64; in Myrmecotypus 64-92). In Mazax the AME are smaller than the ALE (larger in Myrmecotypus) and the abdomen has a distinct, rugose abdominal petiole (only slightly petiolated in Myrmecotypus). Additionally, except for both sexes of M. ajax Reiskind, 1969, males (and some females) of all known species of Mazax have the sec- ond pair of abdominal setae heavily sclerotized into spines. In M. mazaxoides sp. nov., the subequal size of the eyes, the 3—2 ventral spination of tibia I and the elongat- ed, constricted abdomen suggest that MM. mazaxoides sp. nov. represents a transitional form between Mazax and Myrmecoptypus. However, because of the cephalic index (465; 974), the moderately developed petiole, and the simple abdominal setae, we tentatively place M. mazax- oides sp. nov. in Myrmecotypus. Considering the uncertain relationships between Myr- mecotypus and Neotropical Apochinomma and the possi- bility that Myrmecotypus is a polyphyletic group (Reis- 279 kind 1969), a proper phylogenetic analysis, including the analysis of DNA, is needed to facilitate a robust assess- ment of the generic relationships. Mimicry Based on co-occurrence patterns and morphological sim- ilarities, such as a moderately elongated, truncate fore- body, short petiole, and sub-globose abdomen, Perger and Rubio (2020a) hypothesized that Myrmecotypus species are mimics of specific species of the ant tribes Campono- tini or Dolichoderini. However, the six Myrmecotypus species for which ant models have been proposed and their putative models were predominately observed in ar- boreal habitats (Perger and Rubio 2020a, 2021a). The morphological resemblance of M. mazaxoides sp. nov. to Myrmecotypus and Mazax, the latter being an exclusively ground-dwelling genus, and the occurrence of M. mazaxoides sp. nov. in ground habitats suggests that this species represents a transitional form between ground-dwelling and arboreal Castianeirinae lifestyles. A phylogenetic analysis may not only shed light on the ge- neric relationships of Castianeirinae but also on the evo- lutionary history of ant mimicry in this subfamily. Acknowledgments Danilo Harms is thanked for granting permission to work in the Zoological Museum Hamburg, Universitat of Hamburg, Germany, and Gonzalo D. Rubio (Nation- al Research Council of Argentina (CONICET), Experi- mental Station of Agriculture, Misiones, Argentina) and Brogan L. Pett (College of Life and Environmental Sci- ences, University of Exeter, United Kingdom) for a fruit- ful exchange of ideas on castianeirine taxonomy. Many thanks are extended to Charles Haddad (University of the Free State, Bloemfontein, South Africa) and Tamas Sziits (University of Veterinary Medicine Budapest, Budapest, Hungary) for reviewing and improving the manuscript. References de Jager ML, Anderson B (2019) When is resemblance mimicry? Func- tional Ecology 13346: 1365-2435. https://doi.org/10.1111/1365- 2435.13346 Haddad CR (2013) A revision of the ant-like sac spider genus Apochi- nomma Pavesi 1881 (Araneae: Corinnidae) in the Afrotropical re- gion. Journal of Natural History 47(39-40): 2493-2529. https://doi. org/10.1080/00222933.2013.791933 Keyserling E (1891) Die Spinnen Amerikas. Brasilianische Spinnen. Bauer & Raspe, Nurnberg 3: 1-278. https://www.biodiversityli- brary.org/page/41887082 Leister M, Miller K (2014) A new species of ant mimicking spider, Myr- mecotypus jasmineae (Araneae: Corinnidae: Castianeirinae), from Nicaragua. Zootaxa 3838(4): 495-500. https://doi.org/10.11646/ zootaxa.3838.4.8 zse.pensoft.net 280 Perger, R. & Dupérré, N.: A new ant-resembling spider from the Bolivian orocline Navarro G, Ferreira W (2011) Mapa de Sistemas Ecoldgicos de Bolivia, escala 1:250000. RUMBOL SRL-The Nature Conservancy (TNC), Bolivia. [Edicion CD ROM] Perger R, Perger YN (2017) A species richness hotspot of ant-mimick- ing sac spiders (Araneae: Corinnidae: Castianeirinae) at the Boliv- ian Orocline, with new country records for three genera and nine species. Annals of the Entomological Society of America 110(4): 403-408. https://doi.org/10.1093/aesa/sax040 Perger R, Rubio GD (2018) A wolf in sheep’s clothing: The description of a fly resembling jumping spider of the genus Scoturius Simon, 1901 (Araneae: Salticidae: Huriini). PLoS ONE 13(1): e0190582. https://doi.org/10.1371/journal.pone.0190582 Perger R, Rubio GD (2020a) Contributions to the knowledge of Neotropical ant-like spiders: Myrmecotypus tahyinandu sp. n. from Bolivian Chiq- uitano forest, a new country record for M. niger, and indirect evidence for species-specific mimicry (Araneae: Corinnidae: Castianeirinae). Zootaxa 4790(1): 151-164. https://doi.org/10.11646/zootaxa.4790.1.9 Perger R, Rubio GD (2020b) Sympolymnia, a new genus of Neotropi- cal ant-like spider, with description of two new species and indirect evidence for transformational mimicry (Araneae, Salticidae, Sim- onellini). Zoosystematics and Evolution 96(2): 781-795. https://doi. org/10.3897/zse.96.55210 zse.pensoft.net Perger R, Rubio GD (2021la) A new species of Myrmecotypus Pick- ard-Cambridge spider (Araneae: Corinnidae: Castianeirinae) from the Bolivian orocline, imitating one of the world’s most aggressive ants. Insecta Mundi 0860: 1-8. Perger R, Rubio GD (2021b) Myrmecotypus haddadi sp. nov. — a new species of ant resembling sac spider from the Bolivian orocline (Araneae: Corinnidae: Castianeirinae). Zootaxa 4969(1): 054-060. https://doi.org/10.11646/zootaxa.4969.1.2 Reiskind J (1969) The spider subfamily Castianeirinae of North and Central America (Araneae, Clubionidae). Bulletin of the Museum of Comparative Zoology 138: 163-325. Reiskind J (1977) Ant-Mimicry in Panamanian Clubionid and Salticid Spiders (Araneae: Clubioniadae, Salticidae). Biotropica 9(1): 1-8. https://doi.org/10.2307/2387854 Rubio GD, Arbino MO (2009) The first Myrmecotypus O. P.-Cam- bridge (Araneae: Corinnidae) from Argentina: description of Myr- mecotypus iguazu new species. Zootaxa 2158 (1): 65-68. https://doi. org/10.11646/zootaxa.2158.1.6 Rubio GD, Danigsman T (2014) The spider genus Mazax (Araneae: Corinnidae: Castianeirinae) newly recorded from South America, with the description of a new species. Florida Entomologist 97(3): 1182-1190. https://doi.org/10.1653/024.097.0325