Does fertilization with dehydrated sewage sludge affect Terminalia argentea (Combretaceae) and associated arthropods community in a degraded area?

Distribution pattern of arthropods and their ecological interactions on the leaf surfaces of Terminalia argentea saplings

Terminalia argentea tree, native to Brazil, is widely used in landscaping, recovering degraded areas, its wood, coal production, and the bark or leaf extracts has medicinal use. Despite of its importance, the arthropod fauna associated to this plant and its interspecific relationships still needs further studies. The objectives of this study were to evaluate the arthropods, their ecological indices and the distribution in the leaf faces on T. argentea saplings. The numbers of phytophagous insects (e.g., Cephalocoema sp.), pollinators (e.g., Tetragonisca angustula), and natural enemies (e.g., Oxyopidae), and their ecological indices (e.g., species richness), were higher on the adaxial leaf faces on T. argentea saplings. Aggregated distribution of phytophagous insects (e.g., Aphis spiraecola), pollinators (e.g., Trigona spinipes), and natural enemies (e.g., Camponotus sp.) on T. argentea saplings was observed. Abundance, diversity, and species richness of natural enemies correlated, positively, with those of phytophagous and pollinators insects. Predators and tending ants followed their prey and sucking insects, respectively. Tending ants protected sucking insects against predators, and reduced chewing insects. The high number of Cephalocoema sp. on T. argentea saplings is a problem, because this insect can feed on leaves of this plant, but its preference for the adaxial leaf face favors its control. The aggregation behavior of arthropods on T. argentea saplings favors the control of potential pests of this plant. There seems to be competition between tending ants for space and food resources on T. argentea saplings.

Arthropods as possible loss or solution sources on Acacia mangium (Fabales: Fabaceae) saplings

Acacia mangium (Willd.) (Fabales: Fabaceae) tree shows applicability in programs to recover degraded areas due to its fast-growing, rustic, pioneer species, with the potential to fix nitrogen. However, this plant is attacked by pests. It is important to know, among them, the most important. This study aims to evaluate the herbivorous insects (loss sources) and their natural enemies (solution sources) on 48 A. mangium saplings. They were classified according to their ability to damage or reduce the source of damage on these saplings using the percentage of the Importance Index-Production Unknown (% I.I.-P.U.). The loss sources Trigona spinipes Fabr. (Hymenoptera: Apidae), Aleyrodidae (Hemiptera), Phenacoccus sp. (Hemiptera: Pseudococcidae), Aethalion reticulatum L. (Hemiptera: Aethalionidae), and Tropidacris collaris Stoll. (Orthoptera: Romaleidae), showed the highest % I.I.-P.U. on leaves of A. mangium saplings. The solution sources Oxyopidae (Araneae), Pseudomyrmex termitarius (Smith) (Hymenoptera: Formicidae), and Brachymyrmex sp. (Hymenoptera: Formicidae), showed the highest % I.I.-P.U. on leaves of A. mangium saplings. The number of Lordops sp. (Coleoptera: Curculionidae) was reduced per number of Brachymyrmex sp.; that of T. collaris those of Oxyopidae and Brachymyrmex sp.; and that of Tettigoniidae that of P. termitarius, totaling 8.93% of reduction of these herbivorous insects (numbers) on A. mangium saplings. These herbivorous insects turn into problems in commercial plantations of this plant since to are related to pests in some crops. These tending ants and Oxyopidae can be important on A. mangium commercial crops because they can reduce the number of these herbivorous insects.

Phytophagous insects and natural enemies on Sapindus saponaria L. (Sapindales: Sapindaceae) plants fertilized with or without dehydrated sewage sludge

Management programs and efficient techniques are necessary to recover degraded ecosystems. The sewage sludge is rich in nitrogen (N) and with the potential to fertilize Sapindus saponaria L. (Sapinales: Sapindaceae), used in the recovery of degraded areas; this can affect the insect fauna. The study's objective was to evaluate, for 24 months, the abundance of chewing insects, dipterans, pollinators, and predators on S. saponaria plants fertilized with or without dehydrated sewage sludge in a degraded area. The experimental design was completely randomized (with the same characteristics) with two treatments (with or without dehydrated sewage sludge) and 24 replicates, each with one plant. The abundance of Anastrepha sp. (Tephritidae), Cerotoma sp. (Chrysomelidae), Curculionidae, Musca domestica L. (Muscidae), Mantis religiosa L. (Mantodea: Mantidae), Oxyopidae, Salticidae, Tettigoniidae (Orthoptera), and Teudis sp. (Anyphaenidae) was higher on fertilized plants. The abundances of Teudis sp. and Tmarus sp. (Thomisidae) and M. religiosa and Teudis sp. were positively correlated with chewing insects and Diptera, respectively. The population increase of insects and spiders on S. saponaria plants fertilized with dehydrated sewage sludge (bigger crowns) has shown to be suitable for recovering degraded areas with a higher number of niches and better food quality, improving the ecological indices of the area.