Abstract

VECCO, Daniel; PINEDO, Román  and  FERNANDEZ, Miriam. Ecological niche of Pseudophilothrips sp. (Tubulifera: Phlaeothripidae) in the agroecological system of the sacha inchik (Plukenetia volubilis L.) in San Martin, Peru. Rev. Protección Veg. [online]. 2015, vol.30, n.1, pp. 2-5. ISSN 2224-4697.

Promotion of sacha inchik (Plukenetia volubilis L.) cultivation has led to an inadequate agricultural technique with serious consequences on the sustainability of the agricultural system due to phytosanitary problems. During 2007-2009, a total of 202 samplings of adult and nymph populations of Pseudophilothrips sp. (Phlaeothripidae: Tubulifera) were carried out in an agroecological plot of P. volubilis L. at the Center Urku, Tarapoto. The plot was split into one central and four outlying blocks with the same area. A total of twenty five plants, five per block, were previously selected at random with the aid of a sampling plan. Adults and nymphs of the thrips on ten leaves taken from each plant stratum (lower, medium and higher) were recorded, as well as those on ten inflorescences and ten fruits proportionally taken at random from the three strata. The Chi- square test was used to determine the dependence of the recorded frequencies with regard to five dimensions of the ecological niche at the trophic-structural level. The width of the ecological niche for adults and nymphs of the thripsB_{j =} (SSp_ij²)^-1 and the value of the niche overlapping O_ij = (Sp_ijp_ik)(S p_ij²S p_ik²)^-½ were calculated. B_j adults (0,72 ± 0,15) and B_j nymphs (0,52 ± 0,16) showed highly significant differences between them (t =12,9; 201 df; p<0,000); where the nymphs showed a greater capacity of intra-plant aggregation. The value of O_ij, estimated in 60,8 ± 16,9%, could ignore the existence of a greater number of trophic-structural dimensions and another type of intraspecific relationships. The values of the ecological niche width for both development stages as well as their overlapping showed complex patterns of temporaryvariation, whose relationships with population levels could not be satisfactorily explained by a linear correlation analysis.

Keywords : thrips; amplitude of ecological; inka peanut; Plukenetia volubilis.

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