Abstract

LOURENCAO, André L. et al. Resistance of strawberries to Tetranychus urticae Koch (Acari: Tetranychidae). An. Soc. Entomol. Bras. [online]. 2000, vol.29, n.2, pp. 339-346. ISSN 0301-8059.  http://dx.doi.org/10.1590/S0301-80592000000200016.

The performance of eighteen strawberry clones was evaluated in relation to resistance to the two-spotted spider mite Tetranychus urticae Koch. In greenhouse, plants of lineage T-0104 and cultivars 'Blakemore', 'Raritan' and 'IAC Princesa Isabel' had significantly lighter damage symptoms than cultivars 'Cruz' and 'Oso Grande'; under the same conditions, the number of mites per unit area was significantly lower on 'IAC Princesa Isabel' than in 'Cruz', 'Dover' or 'Fern'. In a no-choice experiment conducted in laboratory, average daily oviposition was similar in the different cultivars, although a tendency for lower oviposition was observed on 'IAC Campinas' than on 'Floridabelle', 'Oso Grande' and 'Toyonoka'. An apparent preference of T. urticae for 'IAC Guarani' in relation to 'Floridabelle', 'IAC Campinas' and 'New Jersey 7335-5' was observed in a laboratory multiple-choice experiment involving clones with the highest and lowest oviposition rates in the previous test. Only 'IAC Guarani' of the Brazilian cultivars included in the present work was susceptible to T. urticae, whereas 'IAC Campinas' and 'IAC Princesa Isabel' seem to have levels of resistance similar to the best cultivars developed for this purpose.

Keywords : Fragaria X ananassa Duchesne; plant resistance; two-sppoted spider mite.