Hosting capacity of horticultural plants for insect pests in Brazil

Germano L.D. Leite1*, Marcelo Picanço2, José C. Zanuncio2, Márcio D. Moreira2, and Gulab N. Jham3

Factors such as fertilization, allelochemicals, trichomes, weather, and natural enemies can influence pest populations. Thus, it is necessary to understand the factors that predispose vegetable species to pests and the role of polyculture, crop rotation, and neighboring plants. The objective of this research was to study the hosting capacity for pests of Abelmoschus esculentus (L.), Brassica oleracea L. vars. acephala and capitata, Capsicum annuum L., Cucurbita moschata (Duchesne), Cucurbita maxima Duchesne and Cucumis sativus L., Lycopersicon esculentum Mill., Solanum gilo Raddi and Solanum melongena L., and Phaseolus vulgaris L. The higher density of Bemisia tabaci (Genn.) adults on C. sativus can be due to the higher amount of pentacosane and octacosane in this plant. The occurrence of Brevicoryne brassicae (L.) only in Brassica spp. can be accounted for by the nonacosane of these plants. The low trichome density and greater palmitic acid level can explain the greatest damage by Aphis gossypii Glover in A. esculentum. Empoasca sp. was more frequent in P. vulgaris followed by A. esculentum, which are plants with lower K content. Solanum melongena was attacked more by Hydrangea similis (Walker) and Epitrix sp. perhaps because of higher palmitic acid and 11,14,17-eicosatrienoic methyl ester concentrations in their leaves. Frankliniella sp. exhibited more damage in C. sativus probably owing to higher pentacosane and octacosane in its leaves. Sistena sp. was more frequent in C. maxima and had higher octadecane levels and trichome density. The presence of¥-humulene and hexacosane can explain the damage by Tuta absoluta (Meyrick) on L. esculentum.

Keywords: Trichomes, allelochemicals, nitrogen, potassium, insects.
1Universidade Federal de Minas Gerais/Instituto de Ciências Agrárias, Caixa Postal 135, CEP 39404-006, Montes Claros, Minas Gerais, Brasil. *Corresponding author (gldleite@ig.com.br).
2Universidade Federal de Viçosa (UFV), Departamento de Biologia Animal, CEP 36571-000, Viçosa, Minas Gerais, Brasil. 3Universidade Federal de Viçosa (UFV), Departamento de Química, CEP 36571-000, Viçosa, Minas Gerais, Brasil.