Papers by Antonio José Pérez Sánchez
Biodiversity decreases in response to either intensive management or land abandonment in permanen... more Biodiversity decreases in response to either intensive management or land abandonment in permanent grasslands of Central Europe. Here, we evaluated the long-term impacts of different management regimes on ant richness, nest abun dance, assemblage structure, and food resource use in three experimental grassland sites in Thuringia, Germany. Each experimental site comprised identical management regimes established in 2000 / 2001. Grassland sites differed with respect to plant community type and abiotic conditions. Ants were assessed in four treatments representing a gradient in management intensity: intensive mowing (four-five cuts per year), traditional mowing (two cuts per year), mulching (mulched once per year), and abandonment (no management). A total of fourteen species belonging to three genera were recorded. Overall, ant responses to management treatments were site dependent. Mean species richness did not vary across treatments but sites. Nest abundance was high in the intensive...
Myrmecological News, 2018
Biodiversity decreases in response to either intensive management or land abandonment in permanen... more Biodiversity decreases in response to either intensive management or land abandonment in permanent grasslands of Central Europe. Here, we evaluated the long-term impacts of different management regimes on ant richness, nest abundance, assemblage structure, and food resource use in three experimental grassland sites in Thuringia, Germany. Each experimental site comprised identical management regimes established in 2000 / 2001. Grassland sites differed with respect to plant community type and abiotic conditions. Ants were assessed in four treatments representing a gradient in management intensity: intensive mowing (four-five cuts per year), traditional mowing (two cuts per year), mulching (mulched once per year), and abandonment (no management). A total of fourteen species belonging to three genera were recorded. Overall, ant responses to management treatments were site dependent. Mean species richness did not vary across treatments but sites. Nest abundance was high in the intensive and traditional treatment but strikingly low in the mulching treatment. Assemblages were more diverse in the traditional and abandonment treatment in sites representing semi-dry conditions, while the intensive treatment enhanced ant diversity under mesic site conditions. Higher rates of food monopolization were detected in the intensive and traditional treatment in drier conditions. Our results show that long-term management affected ant assemblages in different ways, but these effects were strongly related to local climate and soil conditions. The responses of ants to grassland management, that is mowing, can be explained by how these management practices (or their absence) affect the microclimatic conditions under a local context. Hence, the interplay of these factors along with the species requirements is of key importance to determining the impact of the land management on ant assemblages in German and Central European grasslands.
Árido-Ciencia, 2017
RESUMEN Las hormigas son consideradas como uno de los grupos zoológicos más importantes de las zo... more RESUMEN Las hormigas son consideradas como uno de los grupos zoológicos más importantes de las zonas áridas y semiáridas, con un papel clave en la caracterización de las comunidades vegetales presentes en esos ecosistemas. No obstante, aún es poco lo que se conoce sobre la composición y estructura de las comunidades de hormigas asociadas a los ambientes áridos y semiáridos en el norte de América del Sur y en particular en Venezuela. A pesar de representar una escasa extensión del territorio venezolano (<5%), este tipo de ambientes puede albergar una riqueza de hormigas considerable, con especies potencialmente únicas para la región. En este estudio, que abarca tres localidades continentales del complejo semiárido Falcón-Lara en la región noroccidental de Venezuela, se emplearon las trampas de caída como medio de recolecta durante las estaciones de lluvia y sequía. Los resultados obtenidos incluyen un total de cinco subfamilias, 18 géneros y 33 especies, que representan los primeros registros para la región, específicamente, para las localidades de Aregue (Edo. Lara), Parque Nacional Cerro Saroche (Edo. Lara) y Agua Larga (Edo. Falcón). En su conjunto, los resultados observados para las localidades venezolanas dan cuenta de una mirmecofauna con una riqueza relativamente alta en comparación con localidades áridas de latitudes templadas y subtempladas en el continente americano, pero baja para ambientes semiáridos del norte de América del Sur. ABSTRACT Ants are considered one of the most important zoological groups in arid and semi-arid zones of the world, where they play a key role in the characterization of the plant communities represented there; however, little is known about the abundance and diversity of the myrmecofauna associated with arid and semiarid environments of Venezuela. Despite representing a small extent of the Venezuelan territory (<5%), this type of environment can house a considerable amount of ants, with species potentially unique to the region. In this study, which examines three continental localities of the Falcón-Lara semiarid complex, in northwestern Venezuela, we used pitfall traps to sample the ant fauna in two contrasting seasons: rainy and dry. The results obtained include five subfamilies, 18 genera and 33 species, which represent the first records for the region, specifically, for localities Aregue (Lara State), Parque Nacional Cerro Saroche (Lara State) and Agua Larga (Falcón State). Taken together, the results observed for the Venezuelan localities account for a myrmecofauna with relatively high species richness compared to temperate and sub-temperate arid localities in the American continent, but low species richness compared to semiarid localities of northern South America.
El chachafruto (Erythrina edulis Triana ex Micheli) es un árbol multipropósito nativo de los Ande... more El chachafruto (Erythrina edulis Triana ex Micheli) es un árbol multipropósito nativo de los Andes tropicales. Tanto sus frutos como sus hojas tienen un alto contenido proteico y propiedades terapeuticas. Desde hace proximadamente 20 años en Venezuela la presencia del chachafruto se ha hecho conspicua debido a algunas iniciativas de siembra, especialmente en el estado Merida, sin embargo, la literatura disponible sobre esta especie ası como su siembra en la zona son escasas. En este trabajo se realiza una breve revisión sobre las características biológicas y agroecológicas de E. edulis y los alcances de las diferentes iniciativas de siembra de esta planta en el estado Mérida, y se documenta cómo ha sido la introducción, adaptación, aceptación, producción e impacto del chachafruto en esta zona.
All members of Triatominae subfamily (Heteroptera: Reduviidae), potential vectors of Trypanosoma ... more All members of Triatominae subfamily (Heteroptera: Reduviidae), potential vectors of Trypanosoma cruzi, etiologic agent of the Chagas disease, feed on blood. Through evolution, these bugs have fixed special morphological,
physiological, and behavioral aptations (adaptations and exaptations) adequate to feed on blood. Phylogeny
suggests that triatomines evolved from predator reduvids which in turn descended from phytophagous
hemipterans. Some pleisiomorphic traits developed by the reduvid ancestors of the triatomines facilitated and
modeled hematophagy in these insects. Among them, mouthparts, saliva composition, enzymes, and digestive
symbionts are the most noticeable. However, the decisive step that allowed the shift from predation to
hematophagy was a change of behavior. The association of a predator reduvid with nesting vertebrate (≈110 to
32 Ma) permitted the shift from an arthropod prey to a vertebrate host. In this work, we review the phylogeny and
dispersion of triatomines and the current controversy over the monophyly or polyphyly of this group. We also
discuss how these insects were able to overcome, and even have taken advantage of, diverse ancestral and
physical barriers to adapt to sucking blood of nidicolous vertebrates. We provide a Spanish version of this work.
There are incomplete data about ant taxonomy and diversity in the Caribbean islands of Venezuela.... more There are incomplete data about ant taxonomy and diversity in the Caribbean islands of Venezuela. In order to broaden myrmecological information in the Peri-Caribbean arid belt, ground-dwelling ant assemblage of the Macanao semi-arid peninsula (Margarita Island) was sampled with a Rapid Assessment Program (RAP). Two study sites on the northern slope of the peninsula were chosen, La Chica (LC) at 70 m of altitude and Cerro Macanao (CM) at 598 m of altitude. Sixty pitfall traps (30 per site) and 96 man-hours of manual collecting (48 man-hours per site) were employed. Overall, 40 species and 32 genera from eight subfamilies were recorded, twice the number of species previously reported for Margarita Island. Differences in ant species richness and structure were detected between both sites, with 31 species in CM and 25 species in LC. Such variations indicate that microclimatic conditions are more favorable in uplands than lowlands in Macanao. This situation may be attributed to the moisture gradient effect upon vegetation, and microclimatic conditions influenced by peninsular orography. Our findings corroborate that the pattern of higher diversity with higher altitude in arid zones also holds for the tropics, and suggest a continental origin for the Lesser Antilles ant fauna.
Ant diversity, Araya Peninsula, Mantel correlograms, neotropics, semi-arid environments
Historic record of Gastrotheca ovifera (Anura: Hemiphractidae): decline evidence in Venezuelan co... more Historic record of Gastrotheca ovifera (Anura: Hemiphractidae): decline evidence in Venezuelan coastal cloud forests. G. ovifera is a marsupial frog of the cloud and riparian forest from Western and Litoral sections of the Venezuelan Cordillera de la Costa (820-2 000m). This amphibian is considered as an endangered species by the IUCN Species Red List, due to its population decline in pristine and well preserved environments. This conservation status is based on anecdotic interpretations. We collected disperse data from museum records (national and international) and explored the possible association between collection records and precipitation data available for the Henri Pittier National Park (PNHP). Likewise, we carried out a systematic population monitoring of G. ovifera in historic and additional localities among the cloud forest of Rancho Grande, PNHP. We found 106 individuals in 11 zoological collections deposited during 1929-2007. After an effort of 646 hours/ person we did not detect G. ovifera individuals in the evaluated localities; as well as no statistical significant associations between the annual precipitation average and the historic records of the species during 1941-1997 period (r s =-0.054, p=0.820, n=19). We discussed the distribution, fluctuation and population changes of this species, analyzing it conservation status. Rev. Biol. Trop. 59 (1): 329-345. Epub 2011 March 01.
Resumen: Reportamos un listado de recursos alimentarios usados por Ectatomma ruidum en un jardín ... more Resumen: Reportamos un listado de recursos alimentarios usados por Ectatomma ruidum en un jardín del Instituto Nacional de Investigaciones Agrícolas (INIA), Maracay, Venezuela. Realizamos 20 sesiones de observación de 15 minutos, distribuidas de manera aleatoria, durante nueve días continuos. Recolectamos e identificamos a nivel de familia los alimentos de E. ruidum mientras eran acarreados por obreras hacia el nido. Obtuvimos un total de 32 recursos alimentarios, constituidos por 16 insectos adultos, seis inmaduros y tres ácaros, entre otros. Nuestros resultados apoyan lo descrito por otros autores, que consideran a E. ruidum como una especie depredadora generalista, y pensamos que la composición de su dieta puede variar en relación al ambiente y la disponibilidad de recursos, exhibiendo preferencia hacia insectos adultos de los órdenes Coleoptera e Hymenoptera. Palabras clave: Hymenoptera, Formicidae, Ectatomma ruidum, hormigas depredadoras, rubros alimenticios, Venezuela. Notes about the diet of Ectatomma ruidum Roger, 1861 (Hymenoptera: Formicidae: Ectatomminae) in a Venezuelan garden Abstract: We report a list of food items used by E.ruidum at Agricultural Research National Institute (Instituto Nacional de Investigaciones Agrícolas, INIA), Maracay, Venezuela. We carried out 20 observation sessions of 15 minutes, randomly distributed along nine continuous days. We collected, and identified to family level, dietary items while being transported by workers. We obtained a total of 32 food items, consisting of 16 adult insects, six immatures, three mites, and others. Our results support previous studies, where E. ruidum is considered as a generalized predator ant, and we think that diet composition in E. ruidum varies in relation to the environment and the availability of trophic resources, with a preference for insects belonging to the Coleoptera and the Hymenoptera. .
Among the Venezuelan salamanders, Bolitoglossa orestes is an endemic species in the Cordillera de... more Among the Venezuelan salamanders, Bolitoglossa orestes is an endemic species in the Cordillera de Mérida; classified as vulnerable (VU D2) and with data deficient (DD) according to the IUCN red list and the red book of the Venezuelan fauna, respectively. Some authors presume that habitat destruction affects population densities of this amphibian; however, there are no conclusive data that confirm this statement. In this sense, we examined the relative abundance of B. orestes in three creeks with different disturbance degrees (Q1: natural disturbance, Q2: without disturbance and Q3: anthropogenic disturbance) in Monte Zerpa cloud forest, Mérida-Venezuela. We carried out nocturnal trackings biweekly during 2005, where we only registered 12 individuals of B. orestes in the Q2 creek. Around 70% of the encounters occurred over ferns and in some cases over shrubs species of Piperaceae family. The spatial disposition of the registered individuals did not vary among precipitation periods (p>> 0.001), while the abundance data showed a positive association with the flow (r s = 0.8, p< 0.05) and the relative humidity (r s = 0.45, p< 0.05). The fecal samples analyzed (n=5) revealed a diet mainly composed by leaf litter dwelling insects (62.5% of the total composition). Despite to the few records of B. orestes (≤1 individual per tracking), our results support the hypothesis that states habitat disturbance as one of the main causes that affects population densities of this amphibian in cloud forests from Cordillera de Mérida, Venezuela.
Nineteen ant species of six subfamilies (Dolichoderinae, Ecitoninae, Ectatomminae, Formicinae, My... more Nineteen ant species of six subfamilies (Dolichoderinae, Ecitoninae, Ectatomminae, Formicinae, Myrmicinae and Ponerinae) and two termite species (Termitidae) from Morón River basin (Carabobo, Venezuela) are listed here as part of a preliminary arthropod research. Despite of reporting a low number of taxa, this work constitutes the first record of ants from Morón, Carabobo state, Venezuela.
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Papers by Antonio José Pérez Sánchez
physiological, and behavioral aptations (adaptations and exaptations) adequate to feed on blood. Phylogeny
suggests that triatomines evolved from predator reduvids which in turn descended from phytophagous
hemipterans. Some pleisiomorphic traits developed by the reduvid ancestors of the triatomines facilitated and
modeled hematophagy in these insects. Among them, mouthparts, saliva composition, enzymes, and digestive
symbionts are the most noticeable. However, the decisive step that allowed the shift from predation to
hematophagy was a change of behavior. The association of a predator reduvid with nesting vertebrate (≈110 to
32 Ma) permitted the shift from an arthropod prey to a vertebrate host. In this work, we review the phylogeny and
dispersion of triatomines and the current controversy over the monophyly or polyphyly of this group. We also
discuss how these insects were able to overcome, and even have taken advantage of, diverse ancestral and
physical barriers to adapt to sucking blood of nidicolous vertebrates. We provide a Spanish version of this work.
physiological, and behavioral aptations (adaptations and exaptations) adequate to feed on blood. Phylogeny
suggests that triatomines evolved from predator reduvids which in turn descended from phytophagous
hemipterans. Some pleisiomorphic traits developed by the reduvid ancestors of the triatomines facilitated and
modeled hematophagy in these insects. Among them, mouthparts, saliva composition, enzymes, and digestive
symbionts are the most noticeable. However, the decisive step that allowed the shift from predation to
hematophagy was a change of behavior. The association of a predator reduvid with nesting vertebrate (≈110 to
32 Ma) permitted the shift from an arthropod prey to a vertebrate host. In this work, we review the phylogeny and
dispersion of triatomines and the current controversy over the monophyly or polyphyly of this group. We also
discuss how these insects were able to overcome, and even have taken advantage of, diverse ancestral and
physical barriers to adapt to sucking blood of nidicolous vertebrates. We provide a Spanish version of this work.