Resistance of maize cultivars to Sitophilus zeamais (Coleoptera: Curculionidae)

Abstract

Five Zea mays cultivars (BRS Caatingueiro, BRS Gorutuba, BRS Sertanejo, BRS Asa Branca and BR 106) were evaluated considering their effect on the nutrition of the maize weevil Sitophilus zeamais, by analysis of total protein in adult fed with these cultivars and for the presence of lectins and trypsin inhibitors in grains. In addition, free-choice and no-choice assays were performed to investigate the resistance of grains of the Z. mays cultivars to an attack by S. zeamais. The BR 106 cultivar showed the lowest susceptibility index, followed by BRS Caatingueiro, BRS Asa Branca, BRS Sertanejo and BRS Gorutuba. The number of emerged adults in the Z. mays cultivars ranged from 213.17 to 74.0, and the lowest number of insects was recorded for the BR 106 cultivar. The insects were able to feed on grains of all cultivars, but the BR 106 cultivar showed the least reduction in dried biomass. Lectins were detected in extracts from BR 106, BRS Asa Branca, BRS Sertanejo and BRS Gorutuba, and the highest activity was shown by BR 106. The lowest protein assimilation was detected in the insects from treatments with BRS Asa Branca. The extracts from all cultivars were able to inhibit the activity of bovine trypsin, but this effect was not related to the resistance degree of Z. mays cultivars. The results suggest the resistance of BR 160 to the attack of S. zeamais, as well as indicating that the presence of lectin in the grains is the cause of this resistance.

Storage of corn seeds infested by weevil

“…Thus, it is important to adopt pest control measures to minimize losses by S. zeamaisin corn seeds during storage. The use of resistant varieties and botanical insecticides for managing of this insect pest (FRAZÃO et al, 2018;NWOSU, 2018) and radiographic analysis for a better evaluation of seeds (FRANÇA-SILVA et al, 2019) are innovations that can contribute to the management of pests in stored seeds.…”

Resistência de genótipos de milho a densidades de Sitophilus zeamais (Coleoptera: Curculionidae)

“…A ausência de alguns fatores relacionados ao nível de resistência ao pericarpo, a natureza física e química da película dos grãos, a presença de aleloquímicos, substâncias fenólicas, amido e proteína, podem ter influenciado numa maior suscetibilidade desses genótipos (RASHID et al, 2021;SSERUMAGA et al, 2021;FRAZÃO et al, 2018;NHAMUCHO et al, 2017;VI et al, 2017). Além disso, se proteínas, amido e minerais permitem que insetos possam ter um maior sucesso no ataque de milho, compostos como fibra bruta, ácido fenólico, inibidores de tripsina e de amilase, podem conferir resistência a S. zeamais (NWOSU, 2015).…”

“…Como alternativa para minimizar esse problema, trabalhos tem buscado por novos métodos de controle, incluindo o uso de variedades resistentes a praga. Essas variedades podem afetar a biologia do inseto, como na perda de peso, menor longevidade, menor oviposição, ciclo de vida, entre outros fatores relacionados com a biologia do inseto (FRAZÃO et al, 2018;KASOZI et al, 2021;NGOM et al, 2021).…”

Eficácia de inseticidas alternativos e biológicos sobre Sitophilus zeamais (Coleoptera: Curculionidae) em grãos de milho

“…Dentre os principais insetos pragas existentes em silos, Sitophilus zeamais (Coleoptera: Curculionidae) conhecido popularmente como gorgulho ou caruncho do milho, apresenta entraves significativos para grãos armazenados, principalmente para milho (Caneppele et al, 2010;Elias & Oliveira, 2009;Frazão et al, 2018).…”