Browsing by Autor "Robert Perger"
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Item type: Item , Item type: Item , A New Species of Johngarthia from Clipperton and Socorro Islands in the Eastern Pacific Ocean (Crustacea: Decapoda: Gecarcinidae)(University of Hawaii Press, 2019) Robert PergerThe taxonomy of the East Pacific land crab Johngarthia planata (Stimpson, 1860) is reviewed and a neotype designated to stabilize the taxonomy of this species. The population of J. planata is found to be restricted to inshore islands and the continental mainland coast of the tropical and subtropical Pacific coast of America. A new species, Johngarthia oceanica sp. nov., is described for populations that occur on the oceanic Clipperton and Socorro islands. Johngarthia oceanica sp. nov., canbeseparatedfromJ. planatabythebroad, subrectangularmesial lobeof the infraorbitalmargin (narrow, subtriangular in J. planata) and a dorsal carapace that is dark yellow to brightly orange with or without black areas of different extension (homogeneously red to maroon in J. planata). The distribution of J. planata is modeled using MaxEnt and the biogeography of East Pacific species of Johngarthia is discussed. The conservation status of the Clipperton population of J. oceanica sp. nov. deserves special attention because this population may be threatened by introduced rats.Item type: Item , A new species of Myrmecotypus Pickard-Cambridge spider (Araneae: Corinnidae: Castianeirinae) from the Bolivian orocline, imitating one of the world's most aggressive ants(Centro Científico Tecnológico - Nordeste, 2021) Robert Perger; Gonzalo D. RubioPerger, Robert, Rubio, Gonzalo D. (2021): A new species of Myrmecotypus Pickard-Cambridge spider (Araneae: Corinnidae: Castianeirinae) from the Bolivian orocline, imitating one of the world's most aggressive ants. Insecta Mundi 2021 (860): 1-8, DOI: 10.5281/zenodo.5041775Item type: Item , A Possible Role of Turtle Ants' Gut Bacterial Symbiosis in Mimicry by a Neotropical Crab Spider(Wiley, 2025) Robert PergerABSTRACT Turtle ants ( Cephalotes spp.) forage on bird droppings because their symbiosis with gut bacteria enables nitrogen uptake. Females of the Neotropical crab spider Aphantochilus rogersi guarding exposed white egg sacs resemble giant turtle ants ( Cephalotes atratus ) at droppings. This ecological context may combine Batesian protection, clutch defense, and predation on turtle ants.Item type: Item , Abundant tiny turtle ants can foster notably speciose mimicry complexes(Wiley, 2024) Robert PergerAbstract In the current study, I report a single‐site mimicry complex involving 20 arthropods from 12 families in five orders resembling the small turtle ant Cephalotes pusillus . The complex is the most species‐rich single‐site complex with predominately Batesian mimics that has been reported so far. Considering that small turtle ants are likely less defended than highly noxious butterflies or aculeate Hymenoptera with potent stingers, possible factors explaining the high species richness of the complex may include high model abundance, small body size and easy to develop morphological resemblance.Item type: Item , Addition to the known long-horned beetle fauna of the Bolivian Andes: A new lycid-like species of Mimolaia Bates, 1885 (Coleoptera, Cerambycidae, Lamiinae, Caliini)(Q15088586, 2019) Robert Perger; Antonio Santos‐SilvaMimolaia batesi sp. nov. from Bolivian Yungas forest is described and illustrated. The new species likely displays Batesian mimicry associated with slender Lycidae species having black elytra and orange/reddish pronotum laterally.Item type: Item , And the Oscar goes to… – Species‐specific ant behaviour related to predator defence in ant‐mimicking spiders(Wiley, 2024) Robert Perger; Gonzalo D. Rubio; Julián E. M. BaigorriaAbstract Mimicry, the superficial resemblance between organisms of two or more species, is considered a textbook example for natural selection, for which it is assumed that predators are important selective agents. Ant mimicking spiders have received considerable attention in studies on mimicry because they include examples with remarkable, species‐specific morphological adaptations. Ant‐like behaviours such as erratic locomotory patterns, abdomen bobbing and vertical movements of the first or second pair of legs to imitate antennal movements, are assumed to have evolved before morphological mimicry and may be considered adaptations to general ant resemblance. Species‐specific behavioural ant mimicry (behaviour that is only observed in specific ants and imitated by their mimics) was very rarely documented and ant resembling behaviour that repels predator attacks has not been confirmed yet. In this study we report and discuss such species‐specific behaviour, a spray display (SD), in the castianeirine spiders Myrmecotypus iguazu (a morphologically accurate mimic of the carpenter ant Camponotus sericeiventris ), and M. tahyinandu (a morphologically accurate mimic of C. crassus ). The SD consisted of the raising of the cephalothorax and moving of the abdomen ventrally under the cephalothorax, pointing the apex forward, and holding the antennae (ant) or first pair of legs (spiders) at an angle of about 45°–120°. The morphological adaptations that are required to perform the SD and the lack of an alternative explanation for the purpose of this display suggest that the SD has evolved to enhance both general behavioural and morphologically accurate ant resemblance. The two observed Myrmecotypus species may be considered the behaviorally most accurate ant‐resembling spiders known to date, as the SD may provide protection against spider‐ and ant‐eating predators at a point in predator interactions where other myrmecomorph spiders may abandon their ant‐resembling behaviour.Item type: Item , Ant‐Mimicking Crab Spiders May Exploit Social Ant Behaviour to Safely Prey on Them(Wiley, 2026) Robert PergerABSTRACT The Neotropical crab spider Aphantochilus rogersi is a Batesian–aggressive mimic of turtle ants, with females guarding egg sacs resembling giant turtle ants feeding on bird droppings. Here I report a preliminary observation indicating that adults may extend this deception into the social domain of their model by carrying giant turtle ants in a way that mimics social nestmate transport. This display likely combines Batesian protection from predators with improved access to prey through aggressive mimicry. Rather than merging multiple deceptive functions within the deceiver, A. rogersi appears to achieve complexity by integrating two non‐communicative contexts of its model species: foraging at bird droppings enabled by gut bacteria symbiosis and the social transport of live nestmates. If confirmed, this behaviour would be conceptually analogous to systems in which predators exploit pre‐existing interactions of their prey—yet here involving an intraspecific cooperative interaction and indirect use of an interspecific ecological context. The case therefore represents a context‐based pathway to complex deception and may constitute the first non‐sexual example of visual aggressive mimicry exploiting a social interaction of the prey.Item type: Item , Description of a new species of the stag beetle genus Auxicerus Waterhouse, 1883 (Coleoptera: Scarabaeoidea: Lucanidae)(Consortium of European Natural History Museums, 2017) Robert Perger; Paschoal Coelho Grossi; Fernando GuerraA new species of the Andean stag beetle genus Auxicerus Waterhouse, 1883 is described from the humid Tucuman-Bolivian forest in the southern Bolivian Andes. Auxicerus magnipunctatus sp. nov. is distinguished from all congeners by the distinctly larger punctures of the mesosternum; antennomeres 2–6 subquadrate, last two joints of club wider than long; lamellae not widely separated; posterior end of ocular canthus rounded and anterior edge of canthus moderately developed into an obtuse triangle. Auxicerus magnipunctatus sp. nov. is possibly endemic to the Tucuman-Bolivian forest. Along with the presence of other endemic beetle species with tropical congeners, the discovery of A. magnipunctatus sp. nov. supports the idea that the persistence of rather tropical taxa in the subtropical realm is fostered by increased humidity at orographic rain barriers and climatic stability in the Tucuman-Bolivian forest.Item type: Item , First records of the jewel beetles Chrysobothris desmaresti (Laporte & Gory, 1836) and Hiperantha stempelmanni Berg, 1889 (Coleoptera: Buprestidae) in Bolivia(Pensoft Publishers, 2015) Robert Perger; Fernando GuerraThe jewel beetle species Chrysobothrisdesmaresti (Laporte & Gory, 1836) and Hiperanthastempelmanni Berg, 1889, have been recorded in Bolivia for the first time. Both species were collected on xeric Acacia trees. As indicated by their presence on Acacia and previous records, both species may be endemic to the arid intermountain valleys of the Southern Bolivian and Northern Argentinean Andes as well as the Chaco lowland forests.Item type: Item , Grismadox elsneri sp. nov. - a new species of ant-resembling sac spider from the Bolivian orocline, with indirect evidence of species-specific mimicry (Araneae: Corinnidae: Castianeirinae)(2026) Robert Perger; Gonzalo D. Rubio; Brogan L. PettItem type: Item , Knocking on Heaven's Door—Remarkable High-Elevation Populations of a Non-Riparian Tiger Beetle Species (Coleoptera: Cicindelidae)(The Coleopterists Society, 2025) Robert Perger; J. Fernando Guerra-SerrudoThe non-riparian tiger beetle species Cylindera (Plectographa) stamatovi (Sumlin, 1979) is herein reported for the first time from Bolivia. The highest of three known Bolivian sites is situated at over 3,600 m above sea level, representing one of the highest known records for a tiger beetle population inhabiting open, non-riparian environments. Specimens included two distinct color morphs: green and cupreous males, and cupreous females. This small-bodied, endemic species appears restricted to open, sandy, non-riparian microhabitats in the Andes of southern Bolivia and northern Argentina. Given the restricted distribution of suitable habitats for C. (P.) stamatovi and the heightened vulnerability of high-Andean flora and fauna to climate change, we recommend further study and inclusion of this species in the upcoming edition of the Bolivian Red Book of Invertebrates to support its long-term conservation.Item type: Item , Longhorn beetles (Coleoptera: Cerambycidae) of the Tucuman-Bolivian forest in the Tariquía Flora and Fauna National Reserve, southern Bolivian Andes, with notes on ecoregion endemism and conservation(Pacific Coast Entomological Society, 2013) Robert Perger; Fernando GuerraThe results of a survey of Cerambycidae in subhumid Tucuman Bolivian forest (TBF) in the Tariquía Reserve, southern Bolivian Andes, are presented. In nine days collecting with beating sheets and a light trap, we obtained records for 93 species of Cerambycidae, including 50 species of Cerambycinae, 42 species of Lamiinae and one species of Prioninae. Ten species are reported for the first time from Bolivia. Two taxa could only be determined to genus and might represent undescribed species. Forty-six percent of the collected species also occur in southeastern Brazil, Paraguay, Argentina and Uruguay. Twenty-three percent of the collected species occur in areas including countries of tropical and subtropical South America and 11% in tropical South America. Fourteen (15%) of the collected species are possibly endemic to Tucuman Bolivian forest. Including the two taxa that may represent new species and seven species that have been reported in the literature from TBF but not collected during our study, the number of potential TBF endemics may be as high as 23. In view of the threats by human land use in Tucuman Bolivian forest, species endemic to this ecoregion warrant special attention in future conservation planning.Se presentan los resultados del estudio de Cerambycidae en el Bosque subtropical Tucumano-Boliviano en la Reserva de Tariquía, en los Andes del Sur de Bolivia. En nueve días de captura con trampas de golpeo y de luz, obtuvimos registros de 50 especies de Cerambycinae, 42 especies de Lamiinae y una especie de Prioninae; resultando en total 93 especies de Cerambycidae. 10 especies están reportadas por primera vez para Bolivia. Dos taxa pudieron ser identificadas sólo hasta el nivel de género y podrían representar a especies aún no descritas. El 46% de las especies capturadas también se encuentran presentes en uno o más de los siguientes países: Sud Este del Brasil, Paraguay, Argentina y Uruguay. El 23% de las especies capturadas fueron reportadas en muchos países en los trópicos y subtrópicos de Sud América y el 11% sólo en los trópicos suramericanos. Posiblemente 14 especies (15%) de los especímenes capturados son endémicas del Bosque Tucumano Boliviano. Incluyendo los dos taxa que podrían representar nuevas especies y siete especies que fueron reportadas en literatura, pero no fueron capturadas durante nuestro estudio, el número de endémicos posibles del Bosque Tucumano Boliviano llegan a 23 especies. Se requiere particular atención en planes de conservación adicionales, considerando las amenazas por el uso del suelo en el Bosque Tucumano Boliviano y el endemismo específico en la región.Item type: Item , Mazax akephaloi sp. nov. - a new Neotropical spider species resembling ‘ headless’ Ectatomma ants (Araneae: Corinnidae: Castianeirinae)(2026) Robert Perger; Brogan L. PettItem type: Item , Mazax akephaloi sp. nov.—a new Neotropical spider species resembling ‘headless’ Ectatomma ants (Araneae: Corinnidae: Castianeirinae)(Q15088586, 2022) Robert Perger; Brogan L. PettA new ant-like spider species of the subfamily Castianeirinae, Mazax akephaloi sp. nov., representing the second species of Mazax recorded from South America, is described from the Bolivian orocline and the Paraguayan Chaco region. The new species superficially resembles Mazax ramirezi Rubio Daniman, 2014, but can be distinguished from this species and all other congeners by a combination of the following characters: feathery setae on the carapace, a tibia I spine formula of 54 in males and 55 in females, the embolus sub-apical with a spatulate extension, the lung-shaped spermathecae II and slightly undulating copulatory ducts. Adults of M. akephaloi sp. nov. were observed foraging in association with workers of the ant Ectatomma permagnum Forel, 1908 on the ground or leaf litter along forest edges. Although the spiders were lacking a structure imitating the head of the ants, they shared several characters (dark brown integument with distinct, coarse wrinkles and shiny reflections, abdomen anteriorly with dorsally pointing process and distinct median constriction) that increased the species-specific similarity to their potential ant models.Item type: Item , Revision of the rhinoceros beetle genus Oryctophileurus Kolbe with description of a new species, the male of O. varicosus Prell, and notes on biogeography (Scarabaeoidea, Dynastinae, Phileurini)(Pensoft Publishers, 2013) Robert Perger; Paschoal Coelho GrossiThe genus Oryctophileurus is reviewed and its validity is supported by a combination of the following apomorphic characters: a single cephalic horn with lateral carina, pronotal cavity with ocellate punctures and two teeth or tubercles close behind the anterior pronotal margin. The male of Oryctophileurus varicosus Prell, 1934, is described for the first time. A new species, Oryctophileurus guerrai Perger & Grossi sp. n., from subhumid Tucuman-Bolivian forest in the Southern Bolivian Andes is described. The new species is distinguished from its closest relative, O. armicollis Prell, 1911, by a narrower distance between the inner teeth of the dorsal pronotal protuberances and a reduced area of weakly developed ocellate punctures above the posterolateral pronotal margin. The occurrence of Oryctophileurus species in areas of endemism along the eastern slope of the tropical Andes suggests that these populations represent biogeographic "relicts", and the discovery of Oryctophileurus guerrai sp. n. in the southern Bolivian Andes suggests that this area is underrated with respect to insect diversity and endemism.Item type: Item , The description of a new calyptrate fly mimicking species of the fungus weevil genus Gymnognathus Schönherr 1826 from the southern Bolivian Andes (Coleoptera: Anthribidae: Anthribinae)(Q15088586, 2016) Robert Perger; Fernando GuerraA new calyptrate fly mimicking species of Gymnognathus Schönherr 1826 from the humid Tucuman-Bolivian forest in the southern Bolivian Andes is described. Gymnognathus barclayi sp. nov. is distinguished from the closest related species G. bohlsi Jordan, 1895, by the color and/or distribution of the scales on the pronotum, fourth ventrite and pygidium, the wider pronotum and the development of the spines on the pygidium. The arrangement of the longitudinal stripes on the pronotum suggests that G. barclayi sp. nov. is a mimic of tachinid or muscid flies. The almost exclusive occurrence of Gymnognathus species in tropical moist forests indicates that the presence of G. barclayi sp. nov. in the subtropical realm is fostered by increased humidity at orographic rain barriers. G. barclayi sp. nov. is possibly endemic to the Tucuman-Bolivian forest. Along with the presence of other endemic species, the discovery of G. barclayi sp. nov. highlights the importance of the Tucuman-Bolivian forest as an endemism hotspot for insects and calls for a re-assessment of the conservation status of this spatially restricted and threatened ecoregion.Item type: Item , The first longhorned beetle record for the Prepuna in the Bolivian Andes and Potosi Department in Bolivia: a new species of Dirocoremia (Coleoptera: Cerambycidae: Rhopalophorini)(Q15088586, 2015) Robert Perger; Fernando GuerraCompared to other Bolivian ecoregions, the Prepuna and Puna in the Bolivian highlands are distinguished by low precipitation and low biological diversity. These factors have likely contributed to the perception that the Prepuna and Puna are less interesting for entomological studies, and reports of longhorned beetles from these regions remain scarce. Here, the first longhorned beetle record for the Bolivian Prepuna and Potosi Department is reported, an unknown species of Dirocoremia Marques, 1994. Dirocoremia tupizai sp. n. can be distinguished from congeners by its dark-brown to black metatibiae with short and sparse subapical brushes of hairs.