El Cielo Biosphere Reserve Research Articles

Compliance with MAB-UNESCO Functions and Management Effectiveness Evaluation between 2017 and 2024: Case Study of the El Cielo Biosphere Reserve, Mexico’s Only State-Run Reserve Belonging to MAB-UNESCO

UNESCO’s MAB Programme promotes a people-centered conservation strategy to strengthen the sustainability of social and ecological systems. However, there exist knowledge gaps regarding its implementation in specific contexts. For this study, a mixed-methods sequential exploratory design was employed. In the first phase, an initial content analysis of the management program of the El Cielo Biosphere Reserve (CBR) and the functions of the statutory framework of UNESCO’s MAB program was conducted. This analysis, which was human-driven but facilitated by artificial intelligence tools, underwent rigorous triangulation and expert validation to strengthen the reliability and robustness of the findings. Subsequently, the Management Effectiveness Tracking Tool (METT3) was issued to researchers, community members, civil servants, and former civil servants related to the management of the CBR. The 2024 results (n = 15) were contrasted with those obtained in 2017 (n = 15) using a quantitative approach consisting of descriptive, non-parametric, and Bayesian statistical techniques. We identified some problems in the implementation of the MAB-UNESCO Programme in the CBR, mainly due to the outdated management program and lack of effective governance, as well as the lack of understanding of the implications of being a MAB-UNESCO biosphere reserve. A numerical trend of deterioration in the effectiveness of the CBR’s management was detected, with overall ratings of 44.78% and 29.62% in 2017 and 2024, respectively. This was associated with a lack of regulation, weak coordination among key actors, and a progressive reduction in funding. The findings of this study are useful to guide the transition of the CBR towards a conservation model that responds to current problems and contributes to the advancement of knowledge on the implementation of the MAB Programme in specific contexts.

A new species of direct-developing frog of the genus Eleutherodactylus (Anura: Eleutherodactylidae) from Tamaulipas, Mexico

The number of species of the subgenus Syrrhophus, genus Eleutherodactylus has increased rapidly in the last eight years, due to recent taxonomic studies. This subgenus of direct-developing frogs is well represented in Mexico, which harbors more than 90% of the species richness reported for the subgenus. In this study, we describe one new species, Eleutherodactylus (Syrrhophus) coelum sp. nov. from the El Cielo Biosphere Reserve in Tamaulipas, Mexico, based on morphological and molecular data. The new species, which was previously assigned to E. cystignathoides, differs from its congeners mainly by its small size and by having the tips of Finger III and IV expanded to twice the width of the narrowest part of these fingers. Phylogenetic analyses recovered a well-supported relationship of the new species as the sister group to an undescribed taxon from San Luis Potosí. This analysis also indicates there are more lineages wating for description.

Hydrological Variability in the El Cielo Biosphere Reserve, Mexico: A Watershed-Scale Analysis Using Tree-Ring Records

The El Cielo Biosphere Reserve (CBR) stands as a vital forested region in eastern Mexico due to its high biodiversity in flora and fauna and provision of environmental services. This study established a network of 10 ring-width chronologies of different species within the CBR and adjacent watersheds. The objective was to analyze their climatic response and reconstruct the seasonal streamflow contribution of each sub-basin to the main stream, utilizing data from a gauge network of eight hydrological stations located at strategic locations of the CBR. With chronologies ranging from 116 to 564 years, most exhibited association with the accumulated streamflow between January and June. Based on the adjusted R2, Akaike Information Criteria, and Variance Inflation Factor, the stepwise regression procedure was selected among different statistical methods for developing the reconstruction model. In spite of differences in the seasonal reconstructed periods, all the species showed potential to develop hydrological reconstructions as indicated by their common response to streamflow variability, as occurred in the wet years of 1976, 1993, 2000, and 2008, and dry years of 1980, 1982, 1996, and 2011. It was found that the response of the chronologies to gauge records increased as a function of the chronologies’ interseries correlation, average mean sensitivity, and distance of the tree-ring series to the gauge station. Streamflow reconstructions at the sub-basin level allowed a better understanding of the hydroclimatic variability characterizing the CBR, but also suggested the need to increase the network of chronologies for some particular sub-basins lacking tree-ring series to improve the reconstructed models.

Evaluation of the diversity and genetic structure of Ceratozamia kuesteriana Regel. (Zamiaceae) in Tamaulipas, Mexico

AbstractGenetic diversity is the most widely used indicator to evaluate the evolutionary potential of a species. In theory, species with limited distribution are more susceptible to diversity loss. However, some species with restricted distribution occasionally present more diversity than expected, as is the case for some cycads. Ceratozamia kuesteriana is a microendemic species in El Cielo Biosphere Reserve in Tamaulipas, Mexico. Several previously reported populations have been eradicated in the last 10 years. The objective of this work was to estimate the levels of diversity and genetic structure in five populations within the reserve. The results show a high structure and differentiation, even when the populations are geographically proximal. However, overall diversity is high, with recent bottlenecks and alleles departing from neutrality, suggesting a broad, well‐adapted genetic base. Unfortunately, this genetic pool has recently become fragmented, posing a high extinction risk if allelic representativeness is absent in collections or botanical gardens.

Scientific mapping of the knowledge on the El Cielo Biosphere Reserve

Abstract: The current knowledge base of the El Cielo Biosphere Reserve (RBC), Tamaulipas, Mexico is identified from scientific publications between 1993 and 2019. Objective: Analyze, synthesize and categorize the studies published on El Cielo Biosphere Reserve (RBC), Tamaulipas. Design/methodology/approach: The methodology focused on the search, classification, and review of existing sources in the SCOPUS database from the perspective of the knowledge base. The study covered 37 publications that were analyzed considering scientific mapping in four dimensions: size, time, space, and composition. The analyses were performed using the Bibliometrix and Biblioshiny software tools. Results: It was found that the reviewed publications address biodiversity studies from a disciplinary approach and from an ecological perspective, which produces a fragmented knowledge of the territory and its problems. Limitations on study/implications: It is recognized that there may be publications that do not appear in the Scopus database Findings/conclusions: Knowledge about the El Cielo Biosphere Reserve is fragmented, with a disciplinary approach and from an ecological perspective. The lack of a critical mass of researchers to generate useful knowledge was observed. A weak intellectual structure was also found, which generates a reduced contribution to the conservation of biodiversity. The original contribution of this paper is the synthesis of the current state of knowledge about biodiversity conservation of the El Cielo Biosphere Reserve, which had not been performed previously.

Temporal and spatial segregation of top predators (Felidae) in a Mexican tropical Biosphere Reserve

Jaguars, Panthera onca (Linnaeus, 1758), and pumas, Puma concolor (Linnaeus, 1771) are the largest felids in the neotropics. Both can overlap in niche axes (time, space and prey), and are therefore potentially competing species. Segregation mechanisms presented by a low overlap in one of these axes of niche can facilitate the coexistence. Our aim was to analyze jaguar and puma temporal and spatial overlap for understanding their segregation mechanisms. Between 2015 and 2017, twenty-six camera trap stations were located in five habitat types of El Cielo Biosphere Reserve (ECBR) in northeastern Mexico. Temporal activity was analyzed using circular statistics and time overlap analysis. Spatial overlap was calculated with the Pianka index and a selectivity habitat analysis. Our results showed that jaguars and pumas were nocturnal and that the temporal overlap was high (∆4 = 0.77). We found an intermediate spatial overlap (Pianka index = 0.61). Jaguars were more selective and preferred the deciduous forest. In comparison, pumas preferred oak-pine forest, but also used oak and deciduous forest. Our results indicate that spatial segregation best explains the coexistence of jaguars and pumas in our study area, probably due to both habitat diversity in the reserve and the generalist habits of the puma.

Contribution of peeling host for epiphyte abundance in two tropical dry forests in the “El Cielo Biosphere Reserve”, Mexico

AbstractHost traits partly determine the abundance and species richness of epiphytes in tropical forests. It has been proposed that older trees with rough bark and evergreens often house more individuals and more epiphytic species than those with thin, smooth, and peeling bark, which harbor few epiphytes. We hypothesize (i) that epiphytes are more abundant and species‐rich in the more shaded forest, which is related to bark roughness, and (ii) that epiphytes are distributed in the middle of the host, where microenvironmental conditions are more favorable to survival. We evaluated abundance, species richness, and vertical distribution of epiphytes in two tropical dry forests, according to the deciduousness and basal area of the trees. Moreover, we selected the most abundant epiphytes to test whether their distribution is related to a specific bark type and examine their vertical distribution in two dry forests. We distinguished a high abundance and species richness of epiphytes in the deciduous forest, although basal area and host species richness were higher in the semi‐deciduous forest. In both forests, we found a positive relationship between epiphyte abundance and basal area. Higher abundance of epiphytes was related to the predominance of Tillandsia schiedeana, a drought‐adapted species, in both forests. Unexpectedly, epiphytes abundantly colonized Bursera simaruba, a host with peeling bark and a very branched crown, where small individuals of T. schiedeana colonized abundantly toward the top of the crown. Our results show the importance of the tropical dry forest, particularly, B. simaruba, in maintaining epiphyte diversity in terms of T. schiedeana colonization.

Análisis de la generación de conocimiento en la Reserva de la Biosfera El Cielo, México y la vinculación con su programa de manejo

La generación, sistematización y transferencia del conocimiento sobre la biodiversidad es un insumo fundamental para su conservación y la inclusión de la comunidad. La Reserva de la Biosfera de El Cielo (RBC), Tamaulipas, México es un área natural protegida por las características de sus recursos bióticos y abióticos. El objetivo de esta investigación fue caracterizar el estado actual del conocimiento generado sobre la Reserva de la Biosfera el Cielo y determinar su relación con su programa de manejo. Se realizó una búsqueda, clasificación y revisión cualitativa y cuantitativa de las fuentes primarias existentes en las bases de datos de Web of Science, Scopus y Redalyc. Esta información se contrastó con el contenido del Programa de Manejo de la RBC. Los resultados muestran asociación indirecta entre publicaciones y programa de manejo, con ausencia de publicaciones en los subprogramas de cultura, comunicación y gestión, así como la necesidad de sistematizar los temas abordados. El principal logro obtenido en este trabajo es la integración, mapeo y sistematización de publicaciones, lo que establece una línea base para estudios futuros. El conocimiento existente sobre la RBC publicado en revistas científicas, se elaboró desde un enfoque disciplinar en el campo de la biología. Existe evidencia de que fue utilizado para elaborar su más reciente programa de manejo y que impacta al menos en el 20 % de las acciones comprendidas en el documento; sin embargo, el proceso para la transferencia del conocimiento fue indirecto y se requieren nuevos enfoques transdisciplinares para abordar la problemática socio-ecológica existente.

El género Hypoxylon (Xylariales, Ascomycota) en el bosque tropical caducifolio de cuatro Áreas Naturales Protegidas de México.

Antecedentes y Objetivos: El género Hypoxylon (Hypoxylaceae) tiene peritecios embebidos en un estroma oscuro o de colores brillantes, efuso-aplanado, efuso-pulvinado o glomerulado, ascas cilíndricas con poro apical amiloide, ascosporas elipsoides, equiláteras o inequiláteras, marrón claro a marrón oscuro, línea germinal recta o sigmoide y perisporio generalmente dehiscente con KOH al 10%. El género tiene una distribución mundial; se han descrito 115 especies con mayor diversidad en las regiones tropicales. En México se tenían registrados 36 taxones, de los cuales 20 se citan del bosque tropical caducifolio. El objetivo del presente estudio es ampliar la distribución conocida y describir las especies de Hypoxylon que crecen en el bosque tropical caducifolio de cuatro Áreas Naturales Protegidas (ANPs) de México.Métodos: Se realizaron seis exploraciones en las siguientes ANPs de México: Reserva de la Biosfera Chamela-Cuixmala (Jalisco), Reserva de la Biosfera Isla Cozumel (Quintana Roo), Reserva de la Biosfera Sierra de Álamos-Río Cuchujaqui (Sonora) y Reserva de la Biosfera El Cielo (Tamaulipas). Los ejemplares recolectados fueron estudiados, descritos y determinados de acuerdo con las técnicas tradicionales en micología. El material está depositado en el herbario ENCB.Resultados clave: Se determinaron 11 especies de Hypoxylon, y se describe por primera vez para México Hypoxylon jaklitschii de Jalisco, Quintana Roo y Tamaulipas. Además, se amplía la distribución conocida de H. anthochroum, H. cinnabarinum, H. erythrostroma, H. haematostroma, H. investiens, H. lividipigmentum, H. perforatum, H. rickii e Hypoxylon subgilvum a otros estados.Conclusiones: Hypoxylon está bien representado en México, siendo uno de los mejor estudiados del orden Xylariales. Hypoxylon cinnabarinum, H. haematostroma e H. lenormandii se encontraron en todas las ANPs del presente estudio. La Reserva de la Biosfera el Cielo es el ANP con mayor número de especies con nueve.

Reserva de la Biósfera El Cielo, Tamaulipas, México: Generación y transferencia del conocimiento para decisiones basadas en evidencia.

En este artículo analizamos y revisamos sistemáticamente el conocimiento científico disponible para la toma de decisiones relacionadas con la conservación de la biodiversidad en la Reserva de la Biosfera El Cielo, Tamaulipas México. La metodología consistió en la búsqueda, clasificación y revisión de publicaciones en las bases de datos de WOS, SCOPUS y REDALYC. Se trabajó con 51 publicaciones científicas en tres niveles, primero se identificaron temas, patrones y estructuras de la investigación, posteriormente se asociaron a los componentes del programa de manejo, y finalmente, la información se presentó a funcionarios relacionados en áreas naturales protegidas. Se concluye que el conocimiento generado del territorio es fragmentado y su problemática no se ha transferido a los tomadores de decisiones.

Habitat use and microhabitat selection of two lizard species with different niche requirements in a resource availability gradient

ABSTRACT Human alteration toward environment modifies the spatial distribution of available resources that influences habitat selection in animals. Thus, it is necessary to identify the resources that determine species occurrence in modified landscapes to provide the basis for future conservation efforts. We evaluated the habitat use and microhabitat selection of two lizard species with different niche requirements in a resource availability gradient caused by disturbance. Surveys were conducted in El Cielo Biosphere Reserve, Mexico, during 2016 and 2017. The gradient was grouped in four environmental types in the function of climatic (temperature and humidity) and structural variables (included different measures of soil, substrate, and vegetation coverage). For each lizard, 11 variables related to the microhabitat structure were recorded. Microhabitat selection for each environment type along the gradient was determined and compared via discriminant analysis. The results showed that Sceloporus variabilis, a species that uses a wide range of resources, can select different microhabitats along the gradient; while Lepidophyma sylvaticum, a species with a restricted use of resources, select microhabitats with similar specific characteristics and avoided disturbed areas with scarce canopy cover. This differential response was related to the degree of specificity in resources selection and physiological restrictions of each species.

Biodiversity risk from land-cover change in terrestrial priority regions and protected natural areas in northeastern Mexico

Protected areas (PAs), priority terrestrial regions (PTRs) and priority terrestrial sites (PTSs) are strategies for conserving natural resources. However, loss of coverage on the peripheries can lead to isolation between these conservation areas. The present study analyzed the association of the change of coverage inside and outside 2 PAs, 5 PTRs and 128 PTSs in Tamaulipas with the richness and geographic distribution of 5 species groups (strict, semiaquatic and tolerant hydrophiles, as well as gastropods and pteridophytes in 3 periods (1986, 2002 and 2011). In addition, we identified areas with similar species composition and socioeconomic-environmental factors related to the change in coverage. The highest richness and geographic distribution of aquatic plants occurred outside the conservation areas, while the greatest richness of ferns and gastropods was present inside them. The greatest loss of coverage occurred outside the El Cielo Biosphere Reserve and the Sierra de Tamaulipas PA. The loss of native cover increased in the last 30 years and is greater outside the conservation areas, therefore is necessary to propose and implement strategies to reduce the isolation of these areas.

Vascular Epiphytic Diversity in a Neotropical Transition Zone Is Driven by Environmental and Structural Heterogeneity

Vascular epiphytes contribute significantly to tropical diversity. Research on the factors that determine vascular epiphytic diversity and composition in tropical areas is flourishing. However, these factors are entirely unknown in tropical-temperate transition zones, which represent the distribution limit of several epiphytic species. We assessed the degree to which climatic and structural variables determine the diversity of vascular epiphytic assemblages (VEAs) in a transition zone in Mexico: the El Cielo Biosphere Reserve. We found 12,103 epiphytic individuals belonging to 30 species and 15 genera along a climatic gradient from 300 to 2,000 m a.s.l. Bromeliaceae and Orchidaceae were the most species-rich families. Forests along the windward slope of the Sierra Madre Oriental (semideciduous forest and tropical montane cloud forest) had higher species richness than forests along the leeward slope (pine-oak forest and submontane scrub). Species richness was largely determined by seasonality and, to a lesser degree, by forest structure, whereas abundance was mainly determined by host tree size. Variation in VEAs composition was largely explained by climatic variables, whereas forest structure was not as important. VEAs differed among forest types and slopes in terms of taxonomic and functional composition. For example, certain bromeliad indicator species reflected differences between slopes. Although within-tree epiphytic species richness (alpha diversity) was low in this transition zone relative to other habitats, species turnover among forest types (beta diversity) was high. These findings suggest that each forest type makes a unique and important contribution to epiphytic diversity in this transition zone.

Richness, Community Structure, and Diurnal Activity of Species of Ants along a Disturbance Gradient at El Cielo Biosphere Reserve, Tamaulipas, Mexico

The effect of environmental variability on species richness, community structure, and daytime activity of ants along a disturbance gradient was examined at El Cielo Biosphere Reserve, Tamaulipas, Mexico. The study site was delimited by LANDSAT satellite images. Ants were evaluated using pitfall traps from 0800 to 1800 every hour for four consecutive days in August 2016. In total, 1190 individuals of 20 species and seven subfamilies were obtained. Six species responded positively to the disturbed environment during the morning, with variation between assessment days. The daytime activity of ant species was variable during the day along the disturbance gradient. Solenopsis geminata was the species that showed the most activity during most of the day in the study. Abundance of species differed between most environments each hour. The total variation explained by the first two axes of the relationship analysis of species abundance and environmental attributes was 83% (Axis 1: Temperature and humidity = 64%, Axis 2: Rocks = 19%). S. geminata and Forelius pruinosus were the species that responded significantly to the variables evaluated. The results suggested that environmental variability along a disturbance gradient determines the establishment of the niche and the diurnal activity profile of each species throughout the day and between days.

Distribución vertical de epífitas y su filogenia en un bosque mesófilo de montaña de Tamaulipas

El bosque mesófilo de montaña en la Reserva de la Biósfera El Cielo se localiza cerca de su límite de distribución boreal. Las plantas epífitas son un componente importante de la biodiversidad de estos bosques, aunque son poco estudiados. En este trabajo se estudiaron las epífitas vasculares en un gradiente altitudinal, y se determinó su preferencia por un hospedero; también se observó que existen diferencias en su distribución sobre los forofitos, así como su distribución vertical sobre su hospedero. Se registró un total de 33 especies epífitas, de las cuales 29 se asociaron, mínimo con un taxón de hospedero. Los taxa arbóreos fueron 24; en 16 de ellas se observó la presencia de al menos una epífita. El número de especies epífitas fue mayor en altitudes menores. De acuerdo con la cantidad de individuos en cada una de las secciones del forofito, se registró una preferencia hacia las zonas III y IV, correspondientes a las partes basal y media de las ramas. La filogenia no estuvo relacionada con la distribución de los taxones en las zonas de los hospederos ni con las altitudes estudiadas. El total de taxa es pequeño, en relación a estudios similares llevados a cabo en latitudes más sureñas, quizá como resultado de un decremento general en la riqueza de especies, asociado con la distancia respecto al Ecuador.

Sequía intraestival en La Reserva de la Biosfera El Cielo y su entorno, Tamaulipas, México

Se evaluó la intensidad y frecuencia de la canícula en la Reserva de la Biosfera El Cielo y se comparó su variabilidad interanual, usando registros pluviométricos mensuales entre 1922 y 2012. La canícula se cuantificó como la disminución relativa del polígono mensual de precipitación durante la temporada de lluvias. El 86% de los veranos analizados en las once estaciones estudiadas presentó canícula. De ellos, en el 55,6% la canícula fue de intensidad débil, en el 23,1%, media, y en el 5,7%, severa. La canícula tiene un comportamiento cíclico, con periodo de nueve años: comienza con intensidad débil, aumenta a media o severa y disminuye a débil. El análisis de tendencia no muestra un incremento del fenómeno.

Management Implications of Estimating Abundance of Quail Inhabiting Forest Environs in Mexico

Estimating abundance of forest quail in Mexico offers unique challenges to wildlife managers. Unlike quail inhabiting grassland, forest quail are often cryptic, live in inaccessible mountainous areas, and unpredictably respond to playback census techniques. During 1996–1999, we estimated abundance of singing quail (Dactylortyx thoracicus) and bearded wood quail (Dendrortyx barbatus) in northeast Mexico. Singing quail were visually counted at El Cielo Biosphere Reserve, Tamaulipas, along 14 transects varying in length from 1,400 to 5,000 m. Because of the cryptic nature of bearded wood quail, visual counts proved unsuccessful in estimating abundance. Therefore, a tape recording of their chorus call was used to determine presence. Vocalizing wood quail were documented at 10 stations on a single 1,000 m transect near Coatepec, Veracruz. Because of the varied habitat types in the area total population estimates were not estimated. Only the numbers present along our transect are reported. Estimates of abundance of singing quail were obtained due to the homogenous habitat. Density estimates from Ejido Lazaro Cardenas for singing quail were 56 quail/45.4 ha (1 quail/0.8 ha). Density estimates for La Cueva were 30 quail/15.9 ha (1 quail/0.53 ha). The management of these quail species presents a substantial challenge for biologists, because of the difficulty in obtaining population estimates. The number of wood quail estimated by each responding individual to the chorus call and possible seasonal elevation shifts of singing quail should be considered when estimates of abundance are used to set harvest regulations.

The El Cielo Biosphere Reserve: Forest Cover Changes and Conservation Attitudes in an Important Neotropical Region

This article combines approaches to better understand both forest cover changes and attitudes toward environmental conservation in the El Cielo Biosphere Reserve in northeastern Mexico. Satellite images are used to document the extent and response of forest cover in the reserve before and after its designation as a biosphere reserve. Ethnographic interviews are also employed to examine the attitudes of local people toward the costs and benefits of the biosphere reserve in their lives. Our research found that unlike many “paper parks,” large-scale deforestation has stopped and forest cover has expanded after the biosphere reserve was created. Our research also found that local people value both tangible and intangible benefits created by the biosphere reserve.

Forecasting cloud forest in eastern and southern Mexico: conservation insights under future climate change scenarios

Assuming that co-distributed species are exposed to similar environmental conditions, ecological niche models (ENMs) of cloud forest species were developed to study how climate change could affect the distribution of cloud forest in eastern and southern Mexico for the year 2050. Using ENM-based predictions and climatic data for IPCC climate change A2 and B2 scenarios, we observed 54–76% reduction of the cloud forest, mainly in the northern region of its current range (Sierra Madre Oriental) and the Pacific slope of Chiapas. With predicted 2050 climate change, cloud forest in the Los Tuxtlas region and El Cielo Biosphere Reserve may face a serious threat of extinction due to the observed upward migration to higher elevations. Our results add to recent studies detecting negative impacts of climate change in montane forests, but the negative impacts of climate change might be exacerbated by current environmental changes in the region. The integration of ecological-niche characteristics of cloud forest in conjunction with projections of extreme climate scenarios constitute a suitable tool to define appropriate areas in which proactive conservation and management strategies should be focused.

Diversity and biogeographic affinities of Apionidae (Coleoptera: Curculionoidea) along an altitudinal gradient in El Cielo Biosphere Reserve of northeastern Mexico

The altitudinal and temporal distributions of species in the family Apionidae (Coleoptera: Curculionoidea) were studied in El Cielo Biosphere Reserve (ECBR) in the state of Tamaulipas, northeastern Mexico. Species richness, diversity and abundance were recorded along an altitudinal gradient, from 100 to 1 900 m. A total of 571 individuals of 51 species were collected, representing 30% of the total species of Apionidae recorded for Mexico. Richness estimators (Chao 2) indicated that 75% of the species present were sampled. Species richness and diversity was greatest in tropical forests. Species geographic distributions were found to fall into 3 categories: mega-Mexico, tropical and temperate. The majority of the species (55.3%) were restricted to mega-Mexico (southern southwestern US to northern Nicaragua), with fewer species with tropical (27.7%) and temperate (17.0%) distributions. Species with tropical distributions had highest diversity and greater overall abundance in low elevations in tropical forests when compared to higher elevation forests (cloud and pine/oak). In contrast, diversity and abundance for species with temperate and mega-Mexican distributions were similar in all forest types. Greater richness and abundance occurred during the dry season (December through May) than the rainy season, suggesting populations of Apionidae were in immature stages during this latter period, with active adults predominating during the dry season, many of which were probably in a non-reproductive physiological state.