ANTIBIOSE E ANTIXENOSE EM CULTIVARES DE GIRASSOL (Helianthus annuus) A LAGARTA-DO-CARTUCHO (Spodoptera frugiperda)

Abstract

Brazil is the second largest producer of oilseeds in the world behind the United States (USDA, 2015), with sunflower cultivation being an important alternative in succession with other grain crops, such as soybeans and corn, and in the composition of different systems of production. With the expansion of this oilseed, insects that had little expression, in terms of incidence and damage, started to occur in greater population intensity, becoming economically important, such as Spodoptera frugiperda. Among the available pest control methods, plant resistance has the advantages of contributing to the reduction of the pest population and being compatible with the other integrated pest management control tactics. One of the advantages of plant resistance to insects is its compatibility with other control methods. Antibiosis is characterized by harmful effects on the biology of the insect and tolerance is the ability of the plant to recover of damage caused by insects, through the production of new vegetative or reproductive structures Antixenosis is observed when one plant is less frequented by the insect compared to other plants on equal terms. This type of resistance is characterized by the behavioral reaction of the insect in relation to the plant. Therefore, the objective was to evaluate, among 21 cultivars, the identification of sunflower cultivars (Helianthus annuus) resistant by antibiosis to the S. frugiperda caterpillar and to evaluate the non-preference for feeding on sunflower cultivars to attack this pest, aiming at its use as an integrated management component. of the insect in the sunflower crop. For antibiosis, the cultivars BRS 55 and BRS 72 were the ones that appeared in four of the six parameters evaluated as viability and period. With regard to nutritional aspects, cultivars with the lowest ingested mass of food and with the highest metabolic cost are the least suitable for feeding the caterpillars, in which the cultivars BRS 71, BRS 72 and SYN 045 stand out. While the BRS genotype 66 stood out as the most repellent with low average number of caterpillars under feeding in this cultivar. Thus, these cultivars showed some type of resistance by antibiosis and antixenosis.