AVALIAÇÃO DE TÁTICAS DE MANEJO INTEGRADO DE PRAGAS ...

Tolerance of citrus genotypes at Phyllocnistis citrella Stainton (Lepidoptera:
Gracillariidae)
Santos, Mônica Silva 1 ; Vendramim, José Djair 1 ; Pitta, Rafael Major 1 ; Lourenção, André Luiz 2 ;
Carvalho, Sheila Salles 1
1 Departamento de Entomologia, Fitopatologia e Zoologia Agrícola. Av Pádua Dias, 11 Caixa
Postal 09, 13418-900, Piracicaba, SP. monicaento1@hotmail.com
2 Instituto Agronômico (IAC), Caixa postal 28, 13012-970, Campinas, SP.
In this study we evaluated tolerance degrees on citrus genotypes based on the damages caused
by Phyllocnistis citrella in order to contribute to Integrated Pest Management of that insect.
The genotypes evaluated were: tangerine ‘Sunki’ (Citrus sunki Hort. ex. Tanaka), hybrids C x
R 4 (C. sunki x Poncirus trifoliata), C x R 315 (C. sunki x P. trifoliata), M x P 222 (C. sinensis x
Tangor Murcott) and Trifoliata Limeira (P. trifoliata). Lemon ‘Rugoso’ (C. jambhiri) was
used as susceptible control. Firstly, a preliminary test was made using the lemon “Rugoso” to
determine the number of couples (0, 3, 6, 9 or 12) necessary to cause a significant damage on
the plants and as well as which parameters should be used for the tolerance determination. The
parameters evaluated were: length of the branches, length and width of the leaves, number of
live larvae in the leaf, damage on the leaves, new sprouts per plant, as well as fresh and dry
branch weight. That assay was conducted at 251 0 C temperature, 7010% relative humidity
and photoperiod of 14L:10D. The results indicated that six couples and 20 larvae per plant
were necessary to cause a significant damage. The parameters selected were: number of new
sprouts per plant, fresh and dry branch weight and damages considering four categories (curled
leaves CL, partially curled leaves PCL, attacked but not damaged leaves ANDL and total
damage TD). To interpret the results, a multivariate analysis was used to generate clusters with
the genotypes. Leaf damage appeared to be the best parameter to evaluate tolerance while fresh
and dry branch weight was not appropriate for this evaluation. With the dendrogram, we can
say that the genotypes Trifoliata Limeira and its hybrid C x R 4 had a tolerant behavior; both
lemon “Rugoso” and tangerine Sunki were susceptible at damages of P. citrella.
Key-words: Citrus leafminer, host plant resistance, tolerance