Insects, tending ants, and spiders on Terminalia argentea (Combretaceae) saplings as bioindicators for the recovery of degraded area.

Abstract

Anthropogenic activities have intensified soil degradation and disrupted essential ecological processes, underscoring the need for effective ecological restoration strategies. Terminalia argentea, a pioneer species of the Cerrado, has demonstrated potential for recovering degraded areas and facilitating arthropod recolonization. Arthropods are sensitive to environmental changes and are thus recognized as bioindicators. This study aimed to assess the recovery of a degraded area by evaluating insect and spider ecological indices, their interactions, and the plant biomass of T. argentea saplings over a two-year field establishment period. Saplings with greater biomass (e.g., more leaves/branch) supported a higher abundance and richness of tending ants. During the first year after planting, the leaves of T. argentea saplings exhibited higher numbers of chewing insects (e.g., Cerotoma sp.) and their ecological indices (e.g., diversity), spiders (e.g., Oxyopidae) and their species richness, bees (e.g., Trigona spinipes) and their abundance, and tending ants (e.g., Brachymyrmex sp.) and their diversity and richness of species. In contrast, saplings in the second year after planting hosted higher numbers of sap-sucking insects (e.g., Aphis spiraecola), their tending ant Camponotus sp., and their Dolichopodidae predators. Saplings with more sap-sucking insects (e.g., Phenacoccus sp.) also had more tending ants (e.g., Camponotus sp.). However, an increase in tending ants (e.g., Ectatomma sp.) was associated with a reduction in predators (e.g., Photinus sp.) and chewing insects (e.g., Lamprosoma sp.). The presence of spiders (e.g., Araneidae) was correlated with higher numbers of chewing insects (e.g., Cephalocoema sp.), while Mantis religiosa and Polybia sp. were more common on saplings with higher defoliation percentages, and Syrphus sp. was associated with Bemisia sp.. These results indicate that trophic interactions, mediated by both bottom-up and top-down mechanisms, structure the arthropod community on T. argentea, promoting the coexistence of functional groups and enhancing ecological indices. Future studies involving predator exclusion and leaf chemical analyses will be essential to deepen this understanding.