Synthesis, Attractiveness and Effectiveness of Chitosan-Tapioca Encapsulates in Atta Sexdens (Hymenoptera: Formicidae)

Abstract

Leaf-cutting ants (genera Atta and Acromyrmex) are defoliation pests of great agronomic importance. Currently, the most effective control method is chemical using granulated baits containing sulfluramid as a standard active ingredient. In this work, a new protocol was proposed for the synthesis of the encapsulates with chitosan, tapioca, citrus pulp and sulfluramid. A sulfluramid is a pesticide which is used extensively in Brazil for management of leaf cutting ants. The main focus of this work is to use a polymeric combination aligned with the active ingredient that allows the formation of an encapsulated which the ants can transport and incorporate to their nests, being an effective methodology for the death of colonies. The encapsulated makes the active ingredient less available to the environment, but maintains the mortality level similar to the used granulated baits. For this reason, it was proposed to develop a chitosan and tapioca encapsulated for the control of leaf-cutting ants.The presence of sulfluramid in the encapsulated was confirmed by Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The behavioral acts related to the transport and the incorporation of leaf disks and encapsulates were observed utilizing A. sexdens colonies. The encapsulates containing sulfluramid have presented a similar intoxication of A. sexdens workers causing mortality in the same proportion as the commercial baits. The protocol for the synthesis of the encapsulates can be utilized with other substances, as entomopathogenic and parasite microorganisms.