Contributions to the knowledge of Neotropical ant-like spiders: Myrmecotypus tahyinandu sp. n. from Bolivian Chiquitano forest, a new country record for M. niger, and indirect evidence for species-specific mimicry (Araneae: Corinnidae: Castianeirinae)

Abstract

Myrmecotypus tahyinandu sp. n. is described from the Bolivian Chiquitano forest, and M. niger Chickering, 1937 is recorded from Bolivia for the first time. The morphological differentiation among the closely related M. tahyinandu sp. n. and M. iguazu Rubio & Arbino, 2009 is likely attributable to the selection for specific ant mimicry. Adults of M. tahyinandu sp. n. are accurate mimics of the ant Camponotus crassus Mayr, 1862, M. iguazu of C. sericeiventris (Guérin-Méneville, 1838), and M. niger of Dolichoderus bispinosus (Olivier, 1792). This study is the first to identify ant models for morphologically closely related Castianeirinae, providing a promising starting point for future research on ant mimicry.

On ant-like Synemosyna Hentz, 1846 spiders from Bolivia, with indirect evidence for polymorphic mimicry complexes (Araneae: Salticidae: Simonellini)

“…In this study, the presence of previously unrecorded species of Synemosyna from Bolivia was not surprising, as the spider fauna of the country is generally poorly known (Cutler 1981a;Perger & Rubio 2018, 2020a, 2020b. The Synemosyna fauna of Tucuman and Chiquitano forests was completely unknown, Table 1.…”

“…provides strong indirect evidence for mimicry. For example, the globose abdomen, less elongated carapace, and long legs in myrmecomorphic sac spiders of the genus Myrmecotypus O. Pickard-Cambridge, 1894 appears to be more spider-like (see Perger & Rubio 2020b).…”

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)

“…Apochinomma acanthaspis Simon, 1896 (BL female type 5 mm), A. armatum Mello-Leitão, 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, constricted abdomen. However, A. acanthaspis and A. armatum have the second pair of setae on the dorsal abdominal sclerite sclerotized to spines, indicating that both may belong 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 Castianeira), and the femora II-IV yellow (see Keyserling 1891).…”

“…Based on co-occurrence patterns and morphological similarities, such as a moderately elongated, truncate forebody, short petiole, and sub-globose abdomen, Perger and Rubio (2020a) hypothesized that Myrmecotypus species are mimics of specific species of the ant tribes Camponotini or Dolichoderini. However, the six Myrmecotypus species for which ant models have been proposed and their putative models were predominately observed in arboreal habitats Rubio 2020a, 2021a).…”

“…Morphologically, these forms resemble specific models of the ant tribes Camponotini and Dolichoderini. Models and mimics share a moderately elongated, 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(Reiskind , 1977 and Mazax O. P.-Cambridge, 1898 (Reiskind 1977;Rubio and Danişman 2014).…”