Ecological indices of phytophagous Hemiptera and their natural enemies on Acacia auriculiformis (Fabales: Fabaceae) plants with or without dehydrated sewage sludge application in a degraded area

Abstract

Soil fertilization with dehydrated sewage sludge (DSS) accelerates the recovery process of degraded areas by improving nutrient concentration, and favors the development of trophic webs with pioneer plants such as Acacia auriculiformis A. Cunn. ex Beth (Fabales: Fabaceae), phytophagous Hemiptera, predators, and protocooperanting ants. This study aimed to evaluate the development and production of A. auriculiformis litter with or without dehydrated sewage sludge application and the ecological indices of sucking insects (Hemiptera), their predators and protocooperating ants, as bioindicators, in a degraded area for 24 months. Complete randomization was applied for two treatments (with or without application of dehydrated sewage sludge) in 24 replications (one repetition = one plant). We evaluated the number of leaves/branch and branches/plant, percentage of soil cover (litter), ecological indices of phytophagous Hemiptera, their predators, and protocooperating ants. The plants of A. auriculiformis, that were applied with dehydrated sewage sludge, had superior development when compared to plants where DSS were not applied. The highest abundance and richness of phytophagous Hemiptera species and Sternorrhyncha predators occurred on A. auriculiformis plants that were applied with dehydrated sewage sludge. The increase in richness of species of protocooperanting ants that established mutualistic relationships positively influenced the phytophagous Hemiptera. The use of A. auriculiformis, with application of dehydrated sewage sludge, can increase recovery of degraded areas due to its higher soil cover (e.g., litter) and results in higher ecological indices of phytophagous Hemiptera and their predators.

Chewing insects, pollinators, and predators on Acacia auriculiformis A. Cunn. ex Beth (Fabales: Fabaceae) plants fertilized with dehydrated sewage sludge

“…), species richness of pollinating insects, and positive correlation between predators and prey (e.g. Araneae and (Dourado et al, 2020), similar to what was presented for A. mangium with this same fertilizer (Silva et al, 2020), perhaps for sewage sludge being rich in nitrogen (Nogueira et al, 2007). Bigger numbers (e.g.…”

“…Greater numbers of Nasutitermes sp. on the trunks of A. auriculiformis trees, fertilized with dehydrated sewage sludge were observed probably, due to the richness of organic matter in this fertilizer (Nogueira et al, 2007) and the higher litter fall production by the plant (Dourado et al, 2020), also, apparent damage or death of these plants was noted, as on A. mangium plants (Silva et al, 2020).…”

“…The parameters, used in these equations, were all significant (P <0.05) according to the selection of the variables by the "Stepwise" method. The data of leaves/ branch and branches/tree of A. auriculiformis, fertilized or not with dehydrated sewage sludge, were described (Dourado et al, 2020).…”

“…abundance) of chewing insects on the leaves, termites on trunks, and species richness of pollinating insects, with predators chasing their prey (e.g. species richness of spider versus that of Orthoptera), on A. auriculiformis plants, fertilized with dehydrated sewage sludge, was possibly recognized, due to the greatest number of leaves and branches of these plants (Dourado et al, 2020). The plants offered extra food and shelter for herbivorous insects, as reported for A. mangium (Silva et al, 2020), besides the greater amount of litterfall (Dourado et al, 2020), favoring the Termitidae, as observed in larger Caryocar brasiliense Camb.…”

Fertilisation with dehydrated sewage sludge affects the phytophagous Hemiptera, tending ants and Sternorrhyncha predators on Acacia mangium (Fabaceae)

“…ex Benth. (Fabales: Fabaceae) and A. mangium (Dourado et al, 2020; Silva et al, 2020), Caryocar brasiliense A. St.‐Hil. (Malpighiales: Caryocaraceae) (Leite et al, 2017) and Terminalia argentea Mart.…”