Resistance of Citrus and Related Genera to Diaphorina citri Kuwayama (Hemiptera: Liviidae)

Abstract

The present study was developed to evaluate the resistance of the following genotypes of Citrus and related genera to this pest: ‘Pera,’ ‘Natal’, and ‘Washington Navel’ oranges (Citrus sinensis), ‘Marsh Seedless’ grapefruit (Citrus paradisi), hardy orange ‘Rubidoux’ (Poncirus trifoliata), kumquat (Fortunella margarita Swingle), citrumelo ‘Swingle’ (C. paradisi x P. trifoliata), and citrange ‘Troyer’ (P. trifoliata x C. sinensis). The experiments were performed in greenhouses with plants grafted onto ‘Rangpur’ lime (Citrus limonia) and placed individually in voile cages. The preference for oviposition in a no-choice test, and the effect of genotype were evaluated. The egg-adult cycle was monitored to determine the effect of genotype on the biology of the insect. Poncirus ‘Rubidoux’ was the least preferred genotype for oviposition; reduced number of eggs was also found to occur on citrange ‘Troyer’, and ‘Marsh Seedless’ was the genotype with the most eggs. No significant variation in the duration of the embryonic period was observed; however, a difference in the viability of eggs was found, with the lowest egg viabilities on ‘Swingle.’ Kumquat and ‘Marsh Seedless’ genotypes were correlated with increased durations of the nymphal phase, however, there was no difference in the survival of this phase. Fecundity of females on ‘Troyer’, ‘Swingle’, and kumquat was reduced. Considering all of the evaluated parameters, it was concluded that cultivars of sweet orange are the most susceptible genotypes to Diaphorina citri. Regarding oviposition, P. trifoliata ‘Rubidoux’ showed resistance of the antixenosis type.