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Sewage sludge is an organic matter-rich material with abundant fractions of nitrogen and other macro and micronutrients, essential for plant growth and development such as Acacia mangium Willd. (Fabales: Fabaceae) used in recovering actions of degraded areas. The objective of this study was to evaluate over 24 months the abundance and diversity of chewing and pollinator insects and arthropod predators on A. mangium plants and the mass production and soil coverage by this plant, fertilized with dehydrated sewage sludge, in a degraded area. The experimental design was in randomized blocks with two treatments (with and without dehydrated sewage sludge) and 24 replications. The number of leaves per branch and branches per plant, defoliation percentage by chewing insects, soil cover and abundance of chewing and pollinator insects and arthropod predators were higher on A. mangium plants fertilized with dehydrated sewage sludge. Nasutitermes sp. (Blattodea: Termitidae) and Trigona spinipes F. (Hymenoptera: Apidae) were the most observed insects on trunks and leaves, respectively, of A. mangium plants fertilized with dehydrated sewage sludge. The A. mangium fertilization increases the populations of different insect and spider groups on this plant.

Interactions of the parasitoids Palmistichus elaeisis Delvare & LaSalle and Trichospilus diatraeae Cherian & Margabandhu (Hymenoptera: Eulophidae) with its alternative host Anticarsia gemmatalis (Hübner) (Lepidoptera: Noctuidae) affect the success or failure of the mass production of these parasitoids for use in integrated pest management programs. The aim of this study was to evaluate changes in the cellular defense and encapsulation ability of A. gemmatalis pupae against P. elaeisis or T. diatraeae in adult parasitoid densities of 1, 3, 5, 7, 9, 11 or 13 parasitoids/pupae. We evaluated the total quantity of circulating hemocytes and the encapsulation rate versus density. Increasing parasitoid density reduced the total number of hemocytes in the hemolymph and the encapsulation rate by parasitized pupae. Furthermore, densities of P. elaeisis above 5 parasitoids/pupae caused higher reduction in total hemocyte numbers. The encapsulation rate fell with increasing parasitoid density. However, parasitic invasion by both species induced generally similar responses. The reduction in defensive capacity of A. gemmatalis is related to the adjustment of the density of these parasitoids to their development in this host. Thus, the role of the density of P. elaeisis or T. diatraeae by pupa is induced suppression of cellular defense and encapsulation of the host, even without them possesses a co-evolutionary history. Furthermore, these findings can predict the success of P. elaeisis and T. diatraeae in the control of insect pests through the use of immunology as a tool for evaluation of natural enemies.

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Galling insects are a highly sophisticated herbivore group on Caryocar brasiliense, a tree that represents the main income source for many communities. The effect of architectural diversity of C. brasiliense trees on galling insect community diversity and abundance was studied. The abundance of adult insects and galled leaves were seven and 1.6 times higher in trees with a greater height/width of canopy (RHW) ratio, respectively. Gall parasitoid richness was 1.8 times greater on trees with higher RHW. Zelus armillatus (Lepeletier & Serville) (Hemiptera: Reduviidae) and ant numbers were 5.8 and 2.7 higher on trees with the largest and smallest RHW, respectively. More complex plant architectures favored species diversity for galling insects and their natural enemies. The competition among four galling insect species for space and feeding and the evidence of “prudence strategy” were, for the first time, observed for galling insects in the Brazilian Cerrado biome.

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