Revista Colombiana de Entomología

Ant community structure and response to disturbances in seasonal semideciduous forest and agricultural matrices in the Brazilian Cerrado

Thu, 31 Jul 2025 00:00:00 -0500

This study examines the structure of epigeic and arboreal ant communities in fragments of Seasonal Semideciduous Forest (SSF) and surrounding matrices (soybean and corn crops and fallow fields) in the Brazilian Cerrado. Ants were collected using baited traps placed along transects perpendicular to the forest fragments. Species specificity and habitat fidelity were evaluated using the indicator species index (IndVal). Environmental variables such as fragment size, litter quantity, and edge proximity did not significantly affect ant richness in SSF. However, non-parametric multidimensional scaling revealed clear differences in community structure between habitats (soil and canopy in SSF, and soil in matrices), and among the three land use states in the matrix (soybean, corn, or uncultivated). Rarefaction curves showed higher ant richness in SSF fragments, in soil and trees. Species composition differed across land uses, in the agricultural matrices, although overall richness did not vary significantly. Based on IndVal, five ant species were identified as indicators of SSF soil, and four as indicators of matrix soil. These patterns demonstrate how land use influences ant communities. Since ants perform vital ecological functions, such as nutrient cycling, seed dispersal and soil structuring, changes in their composition can reflect underlying shifts in ecosystem processes. The presence or absence of specific ant species thus serves as a reliable signal of environmental quality. This reinforces the value of ants as effective bioindicators and highlights the importance of conserving native forest fragments amid expanding agricultural landscapes.

Comparative damage potential of three storage insect pests in stored wheat under laboratory conditions

Tallat Jamshed, Um-i Saleet, Smavia Muzaffar, Muhammad Waqar Hassan — Thu, 04 Sep 2025 00:00:00 -0500

Stored grain pests differ in their feeding behavior and damage potential. This study evaluated the comparative impact of three key storage pests of wheat Tribolium castaneum (Coleoptera: Tenebrionidae), Trogoderma granarium (Coleoptera: Dermestidae), and Sitophilus oryzae (Coleoptera: Curculionidae) under controlled laboratory conditions. Homogeneous-age insects were introduced separately for each species into vials containing 2 grams of whole wheat grains, with three replicates per species, as experiments were conducted independently for all three species. After 35 days, data were recorded on insect survival, number and weight of damaged grains, number and weight of undamaged grains, and percent weight loss. S. oryzae exhibited the highest mean number of live insects (16.67), followed by T. granarium (9.89) and T. castaneum (6.67). S. oryzae also caused the most grain damage (21.33 damaged grains) and the most significant weight loss (16.75 %), followed by T. castaneum (8.56 grains, 2.07 %) and T. granarium (2.56 grains, 0.74 %). Regression analysis revealed a strong relationship between insect number and weight loss for S. oryzae (R² = 0.57) and T. granarium (R² = 0.46), but a weak relationship for T. castaneum (R² = 0.0044), likely due to its lower survival and superficial feeding behavior. These findings provide comparative insights into species-specific damage patterns and may inform more targeted post-harvest pest management strategies.

Susceptibility to propoxur in populations of Aedes aegypti (Diptera: Culicidae) in the department of Córdoba, Colombia

Mon, 06 Oct 2025 00:00:00 -0500

In Colombia, the increased use of pyrethroids and organophosphates in response to rising dengue cases and the emergence of chikungunya and Zika has led to the development of resistance in Aedes aegypti. This highlights the need to explore the effectiveness of other insecticides against Ae. aegypti and the diseases it transmits. In this context, we assessed the susceptibility of 15 Ae. aegypti populations from Córdoba, Colombia, to propoxur, a carbamate insecticide. Susceptibility was evaluated using a standardized bottle assay with a diagnostic dose (DD) of 12.5 μg/bottle and a diagnostic time (DT) of 30 minutes, as recommended by the Centers for Disease Control and Prevention (CDC). The results showed that the evaluated populations were susceptible to propoxur, with 100 % mortality. This finding underscores the potential of propoxur for managing Ae. aegypti in areas where there is resistance to traditional insecticides in the department of Córdoba.

Effect of organic management on the diversity and function of arthropods associated with cacao (Theobroma cacao L.) in Colombia

Juan Camilo Dorado Suárez, Isabelle Merle, Fabrice Requier, Stephane Dupas — Tue, 30 Sep 2025 00:00:00 -0500

Cacao (Theobroma cacao L.) is a high-value commercial crop from which the popular chocolate is derived. Despite its importance, little is known about the associated arthropods and the factors affecting their diversity and functional dynamics. On the other hand, organic farming systems are considered a solution for biodiversity conservation. Consequently, this study aims to compare the abundance and diversity of arthropods, along with their functional roles, evaluating differences between conventional and organic systems. The study was conducted in Nilo, Cundinamarca, Colombia, comparing six conventional and organic cacao plots. Pitfall, interception, Malaise, and floral glue traps were used to recollect arthropods each day over three days in three sampling periods, each attempting to capture a phenological phase of cacao. A total of 273 arthropod families and 15,310 individuals were identified and categorized based on their ecological roles. The results indicate a significant increase in arthropod abundance in organic plots. Additionally, at the functional role level, an effect was found on the abundance of each plot. However, according to the inverse Simpson index, no differences in diversity were found between conventional and organic systems. A negative effect of temperature and precipitation on arthropod abundance was observed across several functional roles. These findings highlight the dynamics of the entomofauna in cacao and how organic management can benefit biodiversity. However, further research is needed to assess its impact on production and societal benefits.