Different levels of shade on population of grasshoppers and its oviposition preference on heliconias/Diferentes niveis de sombreamento na populacao de gafanhotos e sua preferencia para oviposicao em heliconias

Grasshoppers of the families Acrididae and Romaleidae (Orthoptera) are among the insects that defoliate heliconias and have been gaining status as pests of commercial crops of these plants in Brazil. The objectives of the present study were to identify the grasshopper defoliating heliconias in the municipality of Santo Antonio de Padua, RJ (Brazil), to evaluate the effect of different levels of shade on the population of this grasshopper and the production parameters of heliconias, and to determine if this grasshopper has an oviposition preference among the heliconias evaluated. The experiment was in a completely randomized block design, in subdivided plots (four levels of shade in the plot, 0%, 30%, 50% and 80%, and four species of Heliconia: H. psittacorum, H. stricta, H. wagneriana and H. psittacorum x H. spathocircinata 'Golden Torch ' in the subplot), with four replications. The grasshopper was identified as Cornops frenatum frenatum (Acrididae). An increase in shade resulted in a decrease in the number of oviposition holes from the grasshopper and the number of lateral buds. Shade did not influence the number of C. f. frenatum nymphs and adults and the number of flower stems. H. wagneriana was the most preferred species for oviposition by C. f. frenatum. Results suggested using screens to shade heliconia plants can help control C. f. frenatum populations, however, the light requirements of the heliconias should be considered to guarantee productivity. Key words: Orthoptera, Cornops frenatum frenatum, oviposition behavior, tropical flowers, Heliconiaceae. Os gafanhotos das familias Acrididae e Romaleidae (Orthoptera) estao entre os insetos desfolhadores de heliconias, e vem ganhando status de pragas em cultivos comerciais dessas flores no Brasil. O presente estudo objetivou identificar o gafanhoto de ocorrencia no municipio de Santo Antonio de Padua, RJ (Brasil) causador de desfolhamento em heliconias; avaliar o efeito de diferentes niveis de sombreamento sobre a populacao desse gafanhoto e parametros produtivos de heliconias; e se existe preferencia do gafanhoto para oviposicao entre as heliconias avaliadas. O experimento foi em delineamento em blocos ao acaso, em esquema de parcelas subdivididas (quatro niveis de sombreamento: 0%, 30%, 50% e 80% na parcela e quatro especies de Heliconia: H. psittacorum, H. stricta, H. wagneriana e H. psittacorum x H. spathocircinata 'Golden Torch ' na subparcela), com quatro repeticoes. O gafanhoto desfolhador foi i