Parasitóides e predadores associados ao bicudo e lagarta rosada em algodoeiro tratado com caulim

Abstract

Multiple applications of kaolin might be feasible for crop pest management on both conventional and agroecological cotton systems if integrated in harmony with others control strategies. Although kaolin pulverizations in cotton be tested against boll weevil Anthonomus grandis Boheman (Coleoptera: Curculionidae) and others pests, their effect on natural enemies has been neglected. The community of natural enemies in cotton cultivated under low pesticide input is very abundant, diverse, and significant to keep herbivores populations below pest status. The current study investigated the effect of kaolin pulverization on abscission of cotton fruiting structures, emergence of boll weevil and pink bollworm, Pectinophora gossypiella(Saunders) (Lepidoptera: Gelechiidae), and their parasitoids. It was also studied the parasitism of boll weevil by Bracon vulgaris Ashmead (Hymenoptera: Braconidae) in the laboratory. Under field conditions, squares abscission was about 53% less on kaolin-treated plots compared to untreated ones. However the emergence rate of boll weevil and pink bollworm adults from collected structures was similar between treated and untreated plots. The number of bolls per plant (~6 bolls) were not different between the plots. The Survey of natural enemies presents on plant canopy showed seasonal similarity on densities of Areneae, Formicidae, Chrysopidae, and Coccinellidae on kaolin-treated and untreated plots. The parasitoids B. vulgaris and Catolaccus grandis Burks (Hymenopera: Pteromalidae) also exhibited similar emergence rate from structures collected on field treated and untreated with kaolin. Under laboratory conditions, the parasitoid B. vulgaris showed no preference between boll weevil larvae infesting squares treated and untreated with kaolin. Therefore, the results shows that kaolin sprayed in cotton fields does not affect the populations of parasitoids and predators naturally occurring in cotton fields.