Estudo das interaÃÃes planta-herbÃvoro em Laguncularia racemosa (L.) GAERTEN (COMBRETACEAE) no manguezal de MaracaÃpe, Ipojuca, PE

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Interspecific competition is an important force in the ecology of the populations and communities of herbivores. An example that has been neglected is the competition between inductors of gall. These if characterize for being an atypical fabric transformation and/or vegetal agency, being able to be caused by mites, insects, etc. Better to understand the interaction enters foliar an inductive mite of gall and chewing insects in Laguncularia racemosa (L.) Gaerten, we characterize in this work gall observing if it had influence of rainy/dry periods in its demography and we examine if leaves infested for the same one suffer little attack from chewing herbivore and, still if it occurs induced defense in the plant. Monthly excursions to the mangrove of MaracaÃpe, Ipojuca, PE, Brazil had been carried through, (November/2004 to October/2005), to collect leaves of sixty individuals of L. racemosa, in the situations: 40 leaves only with the action of chewing herbivores (FH), 40 that besides being chewing they presented galls (FHG) e, 40 only with galls (FG). The foliares areas of these were gotten by the program ImageTool 3.0. In August beyond these described ones 40 healthy leaves of individuals with little infestation for gall (FS1) and 40 healthy leaves of individuals with accented infestation had been above collected for quantitative phenol analysis (Folin-Ciocalteau method, Test of Tukey) (FS2). For the characterization of gall the mangrove was divided in six parcels (30 x 30m) to monthly collect in the same period 40 galled leaves (2Â - 3Â pair of leaves displayed to the sun) for parcel. Still 40 healthy leaves/parcel had been collected in the month of January (dry period) and in July (rainy period) in order to compare the foliares areas (Test of Mann-Wthiney) between these and the galled leaf. To analyze the space distribution of gall in the leaf and for the level of infestation to the long one of the months, Test of Kruskal-Wallis was used. Gall foliar induced for the mite (Acari: Eriophyidae, Tribe: Eriophyini, Nalepa) is presented crossing the foliares faces, has green coloration, format rounded off and so great medium of length and height of 1,5 x 1,0 mm, respectively. They had been found an average 35 individuals/gall. It has a preferential trend of the mite in inducing gall next to the foliar apex (p <0.01). The comparison of the foliar area between galled and health leaves only presented difference statistics for the rainy station (Z = 39,4; p = <0,05; N = 240), being to the galled leaf with minor area. In this exactly period the number of galls found is significantly lesser, perhaps as a consequence of the locomotion of the mites (generally through the wind) to be engaged because of rains. Gall seems to be influencing the alimentary performance of chewing insects, since leves of L. racemosa with absence of the same one suffers a bigger loss of foliar area through this herbivore. The phenol quantification was bigger in the FG (32,7) that in FHG and FH. One high phenol concentration in this probably is repelling the chewing. One knows that herbivores they tend to prevent leaves previously attacked by insects because this generally containing great concentrations of chemical defenses. The phenol quantification did not demonstrate to be a good indicative of induced defense in L. racemosa, therefore great concentrations had been gotten in the healthy leaf

ASSUNTO(S)

mangrove herbÃvoro anatomia vegetal eriopyidae laguncularia racemosa laguncularia racemosa manguezal herbivore eriopyidae

ACESSO AO ARTIGO

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