Influence of Mineral Particle Films and Biomaterials on Guava Fruits and Implications for the Oviposition of Anastrepha obliqua (Macquart) (Diptera: Tephritidae)

SIMPLE SUMMARY: Among the main phytosanitary problems that affect the production and commercialization of fresh fruits, the occurrence of fruit flies (Diptera: Tephritidae) is one of the main obstacles. The control of these tephritids is mainly performed through the use of toxic baits. The use of mineral films and biomaterials may constitute a viable alternative in relation to the traditional insecticide method, mainly because they do not contaminate the environment and do not leave toxic residues harmful to humans and animals in treated products. Therefore, by modifying the color and texture of the fruit cuticule that covers the plant tissues, kaolin affects the perception of arthropod pests, impairing the localization process and acceptance of the host plant and, consequently, its feeding and oviposition. In this study, we hypothesized that the color changes of guava fruits because of mineral particle films and biomaterials can affect the oviposition of fruit flies. The results obtained are promising and show that mineral films and biomaterials interfering with the color of guavas inhibited the oviposition of A. obliqua. Therefore, they can be used to protect guava fruits from the damage caused by this pest. ABSTRACT: Anastrepha obliqua (Macquart, 1835) is an important pest of tropical fruits, especially Anacardiaceae and Myrtaceae, in the Americas. The objective of this study was to evaluate the influence of mineral films and biomaterials on the coloring of guava fruits (Psidium guajava L.) and implications for the oviposition of A. obliqua. Before the bioassays, color, firmness characteristics, total soluble solids, pH, and titratable acidity were determined to characterize the maturation stage of the fruits. Pieces of guava fruit covered in aluminum foil were immersed in suspensions of mineral particles (Surround(®) WP kaolin; kaolins 605, 607, 608, and 611; and talc) and biomaterials (chitosan, cassava and potato starch, and guar gum) and distilled water (control). After drying, the fruits were exposed to two A. obliqua pairs for 48 h in choice and non-choice tests, and the numbers of eggs per fruit were counted. Mineral films (Surround(®) WP kaolin, and kaolins 605, 607, 608, and 611) and biomaterials (cassava and potato starch) interfered with the color of guava (luminosity, chroma, and hue angle), inhibiting the oviposition of A. obliqua. Talc, chitosan, and guar gum did not influence the oviposition of A. obliqua in guava.