POTENTIAL RISK OF LOSSES IN MAIZE CAUSED BY Dichelops melacanthus (DALLAS) (HEMIPTERA: PENTATOMIDAE) IN BRAZIL

Abstract

ABSTRACT:The incidence of the green belly stink bug, Dichelops melacanthus (Dallas) (Heteroptera: Pentatomidae), on maize crop in Brazil has increased with time, especially due to the continuous availability of food throughout the year. This insect causes injury to seedlings, killing them shortly after their emergence from the soil. If the plant survives, it is possible to see areas with necrotic lesion that increase in a transverse pattern on the sheet, with perforations on the leaves or tillers (side shoots). This pest is currently one of the most important to maize, in conventional and Bt hybrids.The research compared the behavior of theses cultivars infested by the green belly stink bug, D. melacanthus. Bt and conventional maize cultivars were evaluated in a protected environment (greenhouse) and only Bt maize was evaluated at field. Evaluations based on plant development and insect injury occurred after seven days of the infestation period.The results indicated variability among cultivars related to insect infestation, measured by a visual scale for damage determination and plant development. Grain yield obtained from infested plots was 6352.2 kg ha -1 whereas in the non- Sorgo, v.15, n.3, p. 386-397, 2016 ABSTRACT: The incidence of the green belly stink bug, Dichelops melacanthus (Dallas) (Heteroptera: Pentatomidae), on maize crop in Brazil has increased with time, especially due to the continuous availability of food throughout the year. This insect causes injury to seedlings, killing them shortly after their emergence from the soil. If the plant survives,

Multiple resistance to primary pests of grain sorghum hybrids: Spodoptera frugiperda (Lepidoptera: Noctuidae), Diatraea saccharalis (Lepidoptera: Crambidae), and Diceraeus melacanthus (Hemiptera: Pentatomidae)

“…Roza-Gomes et al ( 2011) observed a mean injury score of 2.8 using the density of five stink bugs infested on five maize plants, starting from the V1 stage. In the present study, the use of the injury rating scale modified from maize evaluation was an efficient method to detect differences in susceptibility to GBS between the sorghum hybrids (Roza-Gomes et al, 2011;Duarte et al, 2015;Bridi et al, 2016;Cruz et al, 2016). Therefore, its use can be recommended in future studies evaluating resistance to GBS in grain sorghum.…”

Daños causados por chinche barriga verde Dichelops melacanthus en maíz transgénico Bacillus thuringiensis (Bt)

“…También se ha detectado que una infestación de 3,16 chinches da lugar a una disminución de cerca del 12 % en el largo de la espiga en relación con el tamaño de la espiga sin presencia del insecto. Asimismo, un trabajo similar describe que sin la presencia del insecto el rendimiento del grano de maíz fue de 8.048,43 kg/ha, mientras que, con el insecto, fue de 6.352,21 kg/ha, una diferencia de 21,07 % o 1.696,22 kg/ha (Cruz et al, 2016). (Bortolotto et al, 2016).…”

Subsídios para o manejo de percevejos na fase inicial da cultura do milho

“…Embora estudos apresentem valores divergentes quanto ao impacto de percevejos na fase inicial do milho (CHIARADIA et al, 2016;GOMES et al, 2020), o nível de dano econômico (NDE) atualmente preconizado para percevejos adultos de barriga-verde na fase inicial da cultura do milho situase sempre abaixo de 0,5 percevejo/m de plantas, considerando o impacto da praga na produtividade da cultura, os valores atuais do cereal no mercado e os custos de controle da praga. Todavia, há marcantes variações na suscetibilidade dos genótipos de milho disponíveis no mercado (CROSARIOL NETTO et al, 2015;CRUZ et al, 2016), especialmente quanto à expressão da resistência do tipo tolerância. Além disso, níveis diferenciados de adubação de cobertura podem, em hipótese, mitigar o impacto dos danos de percevejos na fase inicial da cultura, fato em investigação na Epagri/Cepaf.…”

“…Por constituir em uma praga de sistemas, o adequado manejo em culturas antecessoras, como soja, cereais de inverno e plantas de cobertura ou infestantes (Figura 2A), reduz a população de percevejos nas áreas e o impacto na fase inicial do milho. Além disso, a adoção de boas práticas agrícolas, como a dessecação antecipada e o manejo de plantas voluntárias (CRUZ et al, 2016), são medidas de manejo cultural importantes.…”