Abstract

MARTINEZ, FEDRA SOLANGE; FRANCESCHINI, M. CELESTE  and  POI, ALICIA. Food preference Neochetina eichhorniae (Coleoptera: Curculionidae) by aquatic plants of different nutritional value. Rev. Colomb. Entomol. [online]. 2013, vol.39, n.1, pp.81-87. ISSN 0120-0488.

Neochetina eichhorniae (Coleoptera: Curculionidae) is one herbivore associated to Eichhornia crassipes and E. azurea floating meadows in native areas. The aims of this study were: (1) to evaluate the feeding prefe­rence of adults of N. eichhorniae under natural conditions, using native species of macrophytes that coexist with the two host plants, and (2) to assess feeding preference in relation to nitrogen, phosphorous and lignin content as indicators of the nutritive value of the leaves. The plant species included in this study were: E. crassipes, E. azurea, Oxycaryum cubense, Thalia multiflora, Salvinia biloba, Pistia stratiotes, Ludwigia peploides and Nymphaea prolifera. Double and multiple-feeding choice tests were performed under natural conditions, using feeding rations, including and excluding the host plants. Total damaged area per macrophyte and leaf area damaged by weevil were quantified and correlated with the different nutritional values of leaves. The host plants, with damage area varied between 115 and 284.76 mm2, were the most preferred plants. There was a positive correlation between the damage area and the leaf nitrogen content of the plant species. Feeding preference was unrelated to either phosphorous and lignin content or L: N ratio. Neochetina eichhorniae have high specificity for both host plants, which leaves had high nitrogen content. Because the effect of the nutritive value on the feeding preference of invertebrate herbivores from the subtropical aquatic systems remain still unknown, these results are an preliminary contribution.

Keywords : Herbivory; Weevil; Eichhornia crassipes; Specificity; Nitrogen.

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