Synthetic acylsugars and their effects on the control of arthropod pests

Anni Cristini Silvestri Gomes,Luana Isac Soares,Antônio Gilberto Ferreira,Sérgio Scherrer Thomasi,Maria Das Graças Cardoso,Juliano Vilela Resende

doi:10.1590/1413-70542017412031416

Abstract

ABSTRACT One of the main problems facing agriculture is the loss of production as a result of the attack of agricultural pests. Alternative ways to work around this problem are being sought. There are substances called acylsugars that are naturally produced by the wild tomato species S. pennellii and affect arthropod pests. The objectives of this work were to synthesize two acylsugars and assess the biological effect of these on the arthropod pests Bemissia tabaci and Tetranycus urticae. The syntheses were performed via the reactions of glucose and sucrose (saccharose) with acetic anhydride using sodium acetate as the catalyst. The products of these reactions were sucrose octa-acetate and glucose penta-acetate, the structures of which were confirmed by spectroscopic techniques. In a resistance test against the mite, a linear correlation between the concentration of the synthesized substances, and the dislocation of the mite was obtained. A delay in the hatching of the arthropod eggs was observed, causing a mortality rate of approximately 95% in the 1st instar larvae of mites that was confirmed in adults. In the biological tests with Bemisia tabaci, there was a low rate of hatching and emergence, and the effect on the nymphs was the deformation of the emergent adults.

Highlights

According to data from the Food and Agriculture Organization (FAO, 2015), 42.1% of the agricultural production is lost because of several important factors
The infrared spectra of sucrose and glucose are very similar because they possess the same functional groups
The displacement of the mite was affected by the acylsugars, proving that there is a linear relationship between concentration and displacement of arthropod. The application of both synthesized substances resulted in a delay in the emergence of arthropod eggs, causing a mortality of approximately 100% in 1st instar and adult mites

Summary

Introduction

According to data from the Food and Agriculture Organization (FAO, 2015), 42.1% of the agricultural production is lost because of several important factors. 15.6% of this loss is the result of damage of crops by insects. Among the agricultural pests that have caused serious damage to crops, mites of the Tetranychus urticae Koch species (Acari: Tetranychidae) and the whitefly [Bemisia tabaci Genn. The spider mite, Tetranychus urticae, is among the species that cause major damage to crops. The formation of necrotic spots can occur, which causes dryness and premature leaf fall. The attack leads to a decrease in size and number of the fruits and early ripening of the remaining individuals. When the infestation rate in leaflets exceeds 15%, it can lead to substantial losses in production (Moraes; Flechtmann, 2008; Suekane et al, 2012)

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