Biologia e Estudos sobre Resistência à mosca-branca Aleurodicus pseudugesii Martin, 2008 (Hemiptera: Sternorryncha: Aleyrodidae: Aleurodicinae), em coqueiro

Abstract

The species Aleurodicus pseudugesii Martin, 2008 (Hemiptera: Sternorrhyncha: Aleyrodidae: Aleurodicinae) has been found damaging coconut trees in the Northeast, in the states of Alagoas, Bahia, Ceará, Paraíba and Sergipe, in the North, in the state of Rio de Janeiro. The culture of coconut tree is of great economic and social importance for the state of Alagoas because it is cultivated by small, as well as by medium and large farmers. Therefore, problems caused by pests, especially by whitefly, contribute greatly to the low productivity of the crop in the region. In this sense, the use of resistant varieties, which can keep the pests below the levels of economic damage, without causing disturbances, environmental pollution or intoxication of the operators and without leaving residues in the food stands out. A resistant plant can be defined as one that, because of its genotypic constitution, is less damaged than another, under equal conditions, for insect attack. In this way, the present thesis work, in progress, has the following objectives: a) to develop a strategy of control of the whitefly in coconut tree, through the method of varietal resistance; B) to evaluate the constitutive resistance of coconut varieties to whiteflies; C) to evaluate the effect of cis-jasmone as an inducer of resistance in coconut to the whitefly; And D) to identify volatile organic compounds released by the coconut before and after the application of cis-jasmone. The varieties studied in the present study were: dwarf green Jiqui (DGJ), red dwarf Cameroon (DRC), red dwarf Malaysia (DRM), Gramame red dwarf (DRG), Gramame yellow dwarf (DYG), yellow dwarf from Malaysia (DYM). After the biology, it was verified that the duration of the egg-adult phase of the specie Aleurodicus pseudugesii under the conditions of this experiment was 36.2 days. There is difference in longevity and weight between males and females. With the volatile collection and preference tests, it was observed that the volatiles released by the varieties dwarf green of Jiqui (DGJ), red dwarf Cameroon (DRC) and red dwarf Malaysia (DRM) are attractive for A. pseudugesii. The AVG (DRG) variety indicates a possible non-preferred type of resistance (antioxenosis). After application of cis-Jasmone the (DRM) variety showed no preference for A. pseudugesii. (DGJ) and (DRC) are the most preferred for oviposition and landing by adults of A. pseudugesii. In the experiments carried out to evaluate the constitutive and induced resistance, it was observed that the application of cis-jasmone decreased the fecundity of whiteflies A. pseudugesii, in the six varieties studied. The DRC, DRM and DYM strains decreased the viability of A. pseudugesii eggs after the application of cis-jasmone. With the application of cis-jasmone, the genotypes DGJ, DRM, DRG, DYG and DYM showed antixenosis resistance to A. pseudugesii.