The alien species Stenochrus portoricensis (Schizomida: Hubbardiidae): decreasing the Wallacean shortfall in the New World

The widely distributed species, Stenochrus portoricensis Chamberlin, 1922, is recorded for the first time from Costa Rica and Venezuela, and new occurrences from Brazil and Colombia are presented. Morphology of spermathecae from 14 localities is compared and illustrated. The need for studies to evaluate the potential status as an invasive species of S. portoricensis is commented on and a distribution map of the species in southern Central America and South America is given.(AU)

La especie exótica Stenochrus portoricensis Chamberlin, 1922 (Schizomida: Hubbardiidae): disminución del déficit de Wallace en el Nuevo Mundo. La especie de amplia distribución Stenochrus portoricensis Chamberlin, 1922 se registra por primera vez en Costa Rica y Venezuela, y se presentan nuevas ocurrencias en Brasil y Colombia. Se compara e ilustra la morfología de las espermatecas de especímenes provenientes de 14 localidades. Se comenta la necesidad de realizar estudios para evaluar el estatus potencial de S. portoricensis como especie invasora y se presenta un mapa de distribución de la especie en el sur de Centroamérica y Sudamérica.(AU)

Morphology of the arthrodial membrane gland in a Neotropical harvester (Arachnida: Opiliones)

We describe a gland in the arthrodial membrane of the coxa-trochanter articulation in the fourth pair of legs in the Neotropical harvester Mischonyx squalidus Bertkau, 1880. Externally the glandular area has a rough appearance with pores on its surface, with folds of the arthrodial membrane. Internally, its secretory cells have spherical secretory vesicles, smooth endoplasmic reticulum, mitochondria and ducts that exit from the cells and cross the arthrodial membrane. Histochemical tests indicate the presence of proteins and neutral glycoproteins. The function of the gland might be to produce lubricating products that allow better movement of the coxa-trochanter region.

Sampling techniques and environmental variables influence the distribution of pseudoscorpions in urban forest fragments in the central Amazon / Métodos de amostragem e variáveis ambientais influenciam a distribuição de pseudoescorpiões em fragmentos florestais urbanos na Amazônia central

The growth of urban landscapes has genarally reduced biodiversity worldwide. Invertebrates have explored different environments, and it usually takes different sampling techniques to get a representative sample of the species assemblage in a given location. Some studies have sought to determine the minimum necessary number of sampling techniques, including ecological relationships or costs to guide the sampling protocol. In the Amazon, the effect of soil characteristics on invertebrate distribution is well known. We evaluated if sampling techniques have a complementary effect on the detection of pseudoscorpion assemblages and tested whether environmental variables affect the distribution of pseudoscorpion species. The study sites were two urban forest fragments in the city of Manaus, in the central Amazon. In each fragment, we sampled 20 palm trees using the beating technique, and installed transects with 12 sampling points for collection of soil and litter samples for extraction of arthropods in a Berlese funnel and a Winkler extractor, respectively. We collected 267 individuals of 11 species of pseudoscorpions. Most records were obtained through the Winkler extraction in both fragments. The assemblage from the palm trees was different from that in the edaphic samples. Pseudoscorpion species composition also differed significantly between soil and litter, and was influenced by potassium concentration. The number of species in the fragments and the environmental effect on the distribution of pseudoscorpions was similar to that recorded in environmental protection areas, evidencing that urban forest fragments can serve as an efficient repository of Amazonian pseudoscorpion biodiversity.(AU)

O crescimento das paisagens urbanas geralmente reduziu a biodiversidade em todo o mundo. Os invertebrados exploram diferentes ambientes, e geralmente são necessárias diferentes técnicas de amostragem para obter uma amostra representativa da assembleia de espécies em um determinado local. Alguns estudos têm buscado determinar o número mínimo necessário de técnicas de amostragem, incluindo relações ecológicas ou custos para orientar o protocolo de amostragem. Na Amazônia, o efeito das características do solo na distribuição dos invertebrados é bem conhecido. Nós avaliamos se as técnicas de amostragem têm um efeito complementar na detecção de assembleias de pseudoescorpiões e testamos se as variáveis ambientais afetam a distribuição das espécies de pseudoescorpiões. Os locais de estudo foram dois fragmentos florestais urbanos na cidade de Manaus, Amazônia central. Em cada fragmento, amostramos 20 palmeiras com guarda-chuva entomológico e instalamos transectos com 12 pontos amostrais para coleta de solo e serrapilheira para extração de artrópodes em funil de Berlese e extrator de Winkler, respectivamente. Coletamos 267 indivíduos de 11 espécies de pseudoescorpiões. A maioria dos registros foi obtida com Winkler em ambos fragmentos. A assembleia em palmeiras foi diferente das amostras edáficas. A composição de espécies de pseudoescorpiões também diferiu significativamente entre solo e serapilheira, e foi influenciada pela concentração de potássio. O número de espécies nos fragmentos e o efeito ambiental na distribuição de pseudoescorpiões foram semelhantes aos registrados em áreas de proteção ambiental, evidenciando que fragmentos florestais urbanos podem servir como um eficiente repositório da biodiversidade de pseudoescorpiões amazônicos.(AU)

An unusual cryptogeobiid from southeastern Brazil revisited (Opiliones, Laniatores, Gonyleptoidea)

The monotypic genus Bunostigma Mello-Leitão, 1935 is herein revisited. A detailed redescription of its type-species, Bunostigma singulare Mello-Leitão, 1935 from Rio de Janeiro state, eastern Brazil, is herein presented, providing in depth knowledge of this genus. Bunostigma is most closely related to Cryptogeobius Mello-Leitão, 1935, and as this genus, it has a stout complex apophysis on male coxa IV, lacking, however, a second complex on the stigmatic area. Bunostigma has an oblique elongate malleus, similar to that of Zalanodius Mello-Leitão, 1936 (as opposed to a globular malleus in Cryptogeobius). Bunostigma singulare has short legs, with some sexual dimorphism on its stoutness, a dorsal scutum entirely unarmed and an ocularium with an accessory central mound, although unarmed.(AU)

A remarkable new species of Agoristenidae (Arachnida, Opiliones) from Córdoba, Colombia

A new species of Leiosteninae (Opiliones, Agoristenidae) from the Colombian Caribbean, Avima tuttifruttisp. nov.García & Pastrana-M., is described and illustrated, based on two males from the montante forests of Tierralta (Córdoba department). The new species differs externally from other species of Avima by having one yellow hump on mesotergal area IV and green coloration on dorsal scutum. SEM images of the penis and a map showing its distribution are offered. This species represents the first record of a harvestman from the department of Córdoba and the eighth species of the subfamily recorded from the country.(AU)

Cystowithius ankeri sp. nov. (Arachnida: Pseudoscorpiones: Withiidae), a new pseudoscorpion from the Central Andes of Colombia

A new species of the pseudoscorpion genus Cystowithius Harvey, 2004 is described based on several males and females collected in the Cordillera Central near Manizales and Villamaría, Caldas, Colombia. The type series was collected under or on the bark of Eucalyptus grandis W. Hill ex Maiden (Myrtaceae). Cystowithius ankeri sp. nov. is the fifth species in the genus, differing from its four congeners by several characters, including the position of the male sternal invaginations, the length of the movable finger of the pedipalp, and the tactile setae of tarsus IV situated subdistally. A revised identification key to the five species of Cystowithius is also presented. The first barcode (COI gene) of a species of this genus is also provided.

Cystowithius ankeri sp. nov. (Arachnida: Pseudoscorpiones: Withiidae), a new pseudoscorpion from the Central Andes of Colombia

A new species of the pseudoscorpion genus Cystowithius Harvey, 2004 is described based on several males and females collected in the Cordillera Central near Manizales and Villamaría, Caldas, Colombia. The type series was collected under or on the bark of Eucalyptus grandis W. Hill ex Maiden (Myrtaceae). Cystowithius ankeri sp. nov. is the fifth species in the genus, differing from its four congeners by several characters, including the position of the male sternal invaginations, the length of the movable finger of the pedipalp, and the tactile setae of tarsus IV situated subdistally. A revised identification key to the five species of Cystowithius is also presented. The first barcode (COI gene) of a species of this genus is also provided.(AU)

Semideciduous seasonal forest opiliofauna (Arachnida, Opiliones), State of Paraná, Brazil

Harvestmen are arachnids that play an important role in organic matter breakdown. However, there are many ecosystems in Brazil, including Conservation Units, which lack information about these organisms or are sub-sampled. Even in areas of Atlantic forest, a biome that hosts the greatest diversity and endemic rates of these arthropods in the world. In this perspective, the purpose of this study was to survey the harvestmen fauna in areas of Semideciduous Seasonal Forest in the Ilha Grande National Park, Paraná, southern Brazil, from February to November 2019, totaling 15 days and 60 hours, on six islands in the Paraná River. A total of 170 specimens was collected, distributed in five genera, comprising two species and three morphotypes. The low species richness may reflect the isolation of populations imposed by the island effect, however the study expanded the geographic distribution of Parapachyloides uncinatus and Discocyrtus invalidus, for which until then there was no record of occurrence in the Paraná State.

Semideciduous seasonal forest opiliofauna (Arachnida, Opiliones), State of Paraná, Brazil

Harvestmen are arachnids that play an important role in organic matter breakdown. However, there are many ecosystems in Brazil, including Conservation Units, which lack information about these organisms or are sub-sampled. Even in areas of Atlantic forest, a biome that hosts the greatest diversity and endemic rates of these arthropods in the world. In this perspective, the purpose of this study was to survey the harvestmen fauna in areas of Semideciduous Seasonal Forest in the Ilha Grande National Park, Paraná, southern Brazil, from February to November 2019, totaling 15 days and 60 hours, on six islands in the Paraná River. A total of 170 specimens was collected, distributed in five genera, comprising two species and three morphotypes. The low species richness may reflect the isolation of populations imposed by the island effect, however the study expanded the geographic distribution of Parapachyloides uncinatus and Discocyrtus invalidus, for which until then there was no record of occurrence in the Paraná State.(AU)

The hard task of a short-tailed mouse opossum (Monodelphis) to prey a harvestman (Arachnida: Opiliones) / A difícil tarefa de uma cuíca-de-cauda-curta (Monodelphis) para atacar um opilião (Arachnida: Opiliones)

Despite the great diversity of small insectivorous mammals and the use of scent gland secretions as a defense mechanism by harvestmen, there is no observation about the effectiveness of scent glands against predators such as small mammals. We report a remarkable harvestman defense mechanism against a small-mammal attack. When a harvestman and a mouse opossum confronted each other inside a cage, the harvestman knocked out the mouse opossum two sequential times before it could attack the harvestman. Although it is a unique observation and there is no information about its frequency in nature, this report stimulates the study of agonistic behavior between small, cryptic species, which are difficult to observe in the field.(AU)

Apesar da grande diversidade de pequenos mamíferos insetívoros e do uso de secreções odoríferas como mecanismo de defesa por opiliões, não há registros sobre a eficácia das secreções odoríferas contra predadores como os pequenos mamíferos. Relatamos um notável mecanismo de defesa de um opilião contra um ataque de um pequeno mamífero. Quando um opilião e uma cuíca-de-cauda-curta se confrontaram dentro de uma caixa, o opilião nocauteou a cuíca duas vezes consecutivas antes que ela pudesse atacá-lo. Embora seja uma observação única e não haja informações sobre sua frequência na natureza, este registro estimula o estudo do comportamento agonístico entre pequenas espécies crípticas, difíceis de serem observadas em campo.(AU)

The hard task of a short-tailed mouse opossum (Monodelphis) to prey a harvestman (Arachnida: Opiliones) / A difícil tarefa de uma cuíca-de-cauda-curta (Monodelphis) para atacar um opilião (Arachnida: Opiliones)

Despite the great diversity of small insectivorous mammals and the use of scent gland secretions as a defense mechanism by harvestmen, there is no observation about the effectiveness of scent glands against predators such as small mammals. We report a remarkable harvestman defense mechanism against a small-mammal attack. When a harvestman and a mouse opossum confronted each other inside a cage, the harvestman knocked out the mouse opossum two sequential times before it could attack the harvestman. Although it is a unique observation and there is no information about its frequency in nature, this report stimulates the study of agonistic behavior between small, cryptic species, which are difficult to observe in the field.

Apesar da grande diversidade de pequenos mamíferos insetívoros e do uso de secreções odoríferas como mecanismo de defesa por opiliões, não há registros sobre a eficácia das secreções odoríferas contra predadores como os pequenos mamíferos. Relatamos um notável mecanismo de defesa de um opilião contra um ataque de um pequeno mamífero. Quando um opilião e uma cuíca-de-cauda-curta se confrontaram dentro de uma caixa, o opilião nocauteou a cuíca duas vezes consecutivas antes que ela pudesse atacá-lo. Embora seja uma observação única e não haja informações sobre sua frequência na natureza, este registro estimula o estudo do comportamento agonístico entre pequenas espécies crípticas, difíceis de serem observadas em campo.

Cystowithius ankeri sp. nov. (Arachnida: Pseudoscorpiones: Withiidae), a new pseudoscorpion from the Central Andes of Colombia

ABSTRACT A new species of the pseudoscorpion genus Cystowithius Harvey, 2004 is described based on several males and females collected in the Cordillera Central near Manizales and Villamaría, Caldas, Colombia. The type series was collected under or on the bark of Eucalyptus grandis W. Hill ex Maiden (Myrtaceae). Cystowithius ankeri sp. nov. is the fifth species in the genus, differing from its four congeners by several characters, including the position of the male sternal invaginations, the length of the movable finger of the pedipalp, and the tactile setae of tarsus IV situated subdistally. A revised identification key to the five species of Cystowithius is also presented. The first barcode (COI gene) of a species of this genus is also provided.

A remarkable new species of Agoristenidae (Arachnida, Opiliones) from Córdoba, Colombia

Abstract A new species of Leiosteninae (Opiliones, Agoristenidae) from the Colombian Caribbean, Avima tuttifrutti sp. nov. García & Pastrana-M., is described and illustrated, based on two males from the montante forests of Tierralta (Córdoba department). The new species differs externally from other species of Avima by having one yellow hump on mesotergal area IV and green coloration on dorsal scutum. SEM images of the penis and a map showing its distribution are offered. This species represents the first record of a harvestman from the department of Córdoba and the eighth species of the subfamily recorded from the country.

An unusual cryptogeobiid from southeastern Brazil revisited (Opiliones, Laniatores, Gonyleptoidea)

Abstract The monotypic genus Bunostigma Mello-Leitão, 1935 is herein revisited. A detailed redescription of its type-species, Bunostigma singulare Mello-Leitão, 1935 from Rio de Janeiro state, eastern Brazil, is herein presented, providing in depth knowledge of this genus. Bunostigma is most closely related to Cryptogeobius Mello-Leitão, 1935, and as this genus, it has a stout complex apophysis on male coxa IV, lacking, however, a second complex on the stigmatic area. Bunostigma has an oblique elongate malleus, similar to that of Zalanodius Mello-Leitão, 1936 (as opposed to a globular malleus in Cryptogeobius). Bunostigma singulare has short legs, with some sexual dimorphism on its stoutness, a dorsal scutum entirely unarmed and an ocularium with an accessory central mound, although unarmed.

A remarkable new species of Agoristenidae (Arachnida, Opiliones) from Córdoba, Colombia

Abstract A new species of Leiosteninae (Opiliones, Agoristenidae) from the Colombian Caribbean, Avima tuttifrutti sp. nov. García & Pastrana-M., is described and illustrated, based on two males from the montante forests of Tierralta (Córdoba department). The new species differs externally from other species of Avima by having one yellow hump on mesotergal area IV and green coloration on dorsal scutum. SEM images of the penis and a map showing its distribution are offered. This species represents the first record of a harvestman from the department of Córdoba and the eighth species of the subfamily recorded from the country.

An unusual cryptogeobiid from southeastern Brazil revisited (Opiliones, Laniatores, Gonyleptoidea)

Abstract The monotypic genus Bunostigma Mello-Leitão, 1935 is herein revisited. A detailed redescription of its type-species, Bunostigma singulare Mello-Leitão, 1935 from Rio de Janeiro state, eastern Brazil, is herein presented, providing in depth knowledge of this genus. Bunostigma is most closely related to Cryptogeobius Mello-Leitão, 1935, and as this genus, it has a stout complex apophysis on male coxa IV, lacking, however, a second complex on the stigmatic area. Bunostigma has an oblique elongate malleus, similar to that of Zalanodius Mello-Leitão, 1936 (as opposed to a globular malleus in Cryptogeobius). Bunostigma singulare has short legs, with some sexual dimorphism on its stoutness, a dorsal scutum entirely unarmed and an ocularium with an accessory central mound, although unarmed.

Quantitative study of wild animals received at the Wild Animals Triage Centers (CETAS) in Bahia and identification of trafficking routes / Estudo quantitativo de animais silvestres recebidos nos Centros de Triagens de Animais Silvestres (CETAS) da Bahia e identificação de rotas de tráfico

In Brazil, the illegal capture of wild animals is a crime that contributes to the extinction of species, besides causing environmental imbalance and suffering to the animals. Here, we undertook a quantitative survey of animals sent to the "Centro de Triagem de Animais Silvestres" (CETAS - Wild Animals Triage Centers) from units of Porto Seguro, Salvador, and Vitória da Conquista during 2009-2019. The 19,317, 34,460, and 43,874 specimens were registered in the units of Porto Seguro, Vitória da Conquista, and Salvador, respectively. The distribution of the totals by class included 80,948 (82.90%) birds, 12,007 (12.30%) reptiles, 4,661 (4.77%) mammals, and 35 arachnids (0.03%). The operations that generated registration at the CETAS were most frequently apprehensions (67,974; 69.67%), followed by voluntary surrender (13,367; 13.69%), rescues (12,803; 13.11%), and transfers (2,735; 2.67%). The animals came from 236 municipalities in the state of Bahia, with emphasis on the municipalities of Salvador, Vitória da Conquista, Feira de Santana, Lençóis, Jequié, and Paulo Afonso. The evaluation of the quantitative seizures by municipalities indicates that the BR-116 is one of the most representative routes for the illegal traffic of wild animals in the state of Bahia and the country.(AU)

No Brasil a captura ilegal de animais silvestres é crime e contribui para a extinção das espécies, além de causar desequilíbrios ambientais e sofrimentos aos animais. Este trabalho apresenta quantitativos de animais recebidos e/ou armazenados nos Centros de Triagem de Animais Silvestres (CETAS) do estado da Bahia, no período de 2009-2019. Os totais de 19.317, 34.460 e 43.874 espécimes foram registrados nas unidades de Porto Seguro, Vitória da Conquista e Salvador, respectivamente. A distribuição dos totais por classe incluiu 80.948 (82,90%) aves, 12.007 (12,30%) répteis, 4.661 (4,77%) mamíferos e 35 aracnídeos. Quanto à natureza da operação que gerou o registro nos CETAS, as mais frequentes foram apreensão (67.974; 69,67%), entrega voluntária (13.367; 13,69%), resgate (12.803; 13,11%) e transferência (2.735; 2,67%). Os animais foram apreendidos em 236 municípios do estado da Bahia, com destaque para Salvador, Vitória da Conquista, Feira de Santana, Lençóis, Jequié e Paulo Afonso. A avaliação dos quantitativos das apreensões por municípios indica que a BR-116 é uma das rotas de escoamento mais representativa do tráfico ilegal de animais silvestres, no estado da Bahia e no país.(AU)

Quantitative study of wild animals received at the Wild Animals Triage Centers (CETAS) in Bahia and identification of trafficking routes / Estudo quantitativo de animais silvestres recebidos nos Centros de Triagens de Animais Silvestres (CETAS) da Bahia e identificação de rotas de tráfico

In Brazil, the illegal capture of wild animals is a crime that contributes to the extinction of species, besides causing environmental imbalance and suffering to the animals. Here, we undertook a quantitative survey of animals sent to the "Centro de Triagem de Animais Silvestres" (CETAS - Wild Animals Triage Centers) from units of Porto Seguro, Salvador, and Vitória da Conquista during 2009-2019. The 19,317, 34,460, and 43,874 specimens were registered in the units of Porto Seguro, Vitória da Conquista, and Salvador, respectively. The distribution of the totals by class included 80,948 (82.90%) birds, 12,007 (12.30%) reptiles, 4,661 (4.77%) mammals, and 35 arachnids (0.03%). The operations that generated registration at the CETAS were most frequently apprehensions (67,974; 69.67%), followed by voluntary surrender (13,367; 13.69%), rescues (12,803; 13.11%), and transfers (2,735; 2.67%). The animals came from 236 municipalities in the state of Bahia, with emphasis on the municipalities of Salvador, Vitória da Conquista, Feira de Santana, Lençóis, Jequié, and Paulo Afonso. The evaluation of the quantitative seizures by municipalities indicates that the BR-116 is one of the most representative routes for the illegal traffic of wild animals in the state of Bahia and the country.(AU)

No Brasil a captura ilegal de animais silvestres é crime e contribui para a extinção das espécies, além de causar desequilíbrios ambientais e sofrimentos aos animais. Este trabalho apresenta quantitativos de animais recebidos e/ou armazenados nos Centros de Triagem de Animais Silvestres (CETAS) do estado da Bahia, no período de 2009-2019. Os totais de 19.317, 34.460 e 43.874 espécimes foram registrados nas unidades de Porto Seguro, Vitória da Conquista e Salvador, respectivamente. A distribuição dos totais por classe incluiu 80.948 (82,90%) aves, 12.007 (12,30%) répteis, 4.661 (4,77%) mamíferos e 35 aracnídeos. Quanto à natureza da operação que gerou o registro nos CETAS, as mais frequentes foram apreensão (67.974; 69,67%), entrega voluntária (13.367; 13,69%), resgate (12.803; 13,11%) e transferência (2.735; 2,67%). Os animais foram apreendidos em 236 municípios do estado da Bahia, com destaque para Salvador, Vitória da Conquista, Feira de Santana, Lençóis, Jequié e Paulo Afonso. A avaliação dos quantitativos das apreensões por municípios indica que a BR-116 é uma das rotas de escoamento mais representativa do tráfico ilegal de animais silvestres, no estado da Bahia e no país.(AU)

The hard task of a short-tailed mouse opossum (Monodelphis) to prey a harvestman (Arachnida: Opiliones)

ABSTRACT Despite the great diversity of small insectivorous mammals and the use of scent gland secretions as a defense mechanism by harvestmen, there is no observation about the effectiveness of scent glands against predators such as small mammals. We report a remarkable harvestman defense mechanism against a small-mammal attack. When a harvestman and a mouse opossum confronted each other inside a cage, the harvestman knocked out the mouse opossum two sequential times before it could attack the harvestman. Although it is a unique observation and there is no information about its frequency in nature, this report stimulates the study of agonistic behavior between small, cryptic species, which are difficult to observe in the field.

RESUMO Apesar da grande diversidade de pequenos mamíferos insetívoros e do uso de secreções odoríferas como mecanismo de defesa por opiliões, não há registros sobre a eficácia das secreções odoríferas contra predadores como os pequenos mamíferos. Relatamos um notável mecanismo de defesa de um opilião contra um ataque de um pequeno mamífero. Quando um opilião e uma cuíca-de-cauda-curta se confrontaram dentro de uma caixa, o opilião nocauteou a cuíca duas vezes consecutivas antes que ela pudesse atacá-lo. Embora seja uma observação única e não haja informações sobre sua frequência na natureza, este registro estimula o estudo do comportamento agonístico entre pequenas espécies crípticas, difíceis de serem observadas em campo.

Scorpions (Arachnida, Scorpiones) from the state of Acre, southwestern Brazilian Amazon / Escorpiones (Aracnida, Scorpiones) del estado de Acre, suroeste de la Amazonía brasileña

Aunque Brasil tiene una de las diversidades de escorpiones más altas del mundo, la fauna de escorpiones de la región amazónica sigue siendo relativamente poco descrita. En este estudio, actualizamos la lista de especies de escorpiones para el estado de Acre, en el suroeste de la Amazonía brasileña, en base a una revisión de los registros contenidos en colecciones de arácnidos brasileños y un estudio de la literatura relevante. Registramos la ocurrencia de siete especies de escorpiones pertenecientes a dos familias (Buthidae y Chactidae), entre las cuales informamos tres nuevos registros (Ananteris sp., Tityus (Tityus) gasci y Chactopsis cf. insignis) para Acre. Los resultados presentados aquí hacen una contribución importante al conocimiento acerca de la diversidad de escorpiones en los bosques amazónicos de Acre.(AU)

Although Brazil has one of the highest scorpion diversities worldwide, the scorpion fauna of the Amazon region remains relatively poorly described. In this study, we updated the list of scorpion species from the state of Acre, in the southwestern Brazilian Amazon, based on a revision of records contained in Brazilian arachnid collections and a survey of the relevant literature. We recorded the occurrence of seven scorpion species belonging to two families (Buthidae and Chactidae) among which we report three new records (Ananteris sp., Tityus (Tityus) gasci, and Chactopsis cf. insignis) for Acre. The results presented herein make an important contribution to the knowledge on scorpion diversity in the Amazonian forests of Acre.(AU)