SEASONAL VARIATION OF LEPIDOPTERA LEAFMINERS AND their PARASITOIDS IN SPONTANEOUS VEGETATION IN AN ORGANIC CITRUS ORCHARD IN MONTENEGRO, RS, BRAZIL

J.P. dos Santos L.R. Redaelli F.K. Dal Soglio E. Foelkel V.A. Costa About the authors

ABSTRACT

Phyllocnistis citrella (Lepidoptera: Gracillariidae), known popularly as “citrus leafminer,” is one of the main insect-pests of citrus orchards in many countries. This study was aimed to determine the species and the seasonal variation of Lepidoptera leafminers and their parasitoids, present in the vegetation spontaneously growing in a citrus orchard, to verify if P. citrella is present in other host plants and if the parasitoids of other leafminers are the same ones reported for this insect-pest. The work was conducted in Montenegro, state of Rio Grande do Sul, Brazil, in an organic orchard of the Murcott cultivar. Samplings were taken fortnightly, from May 2003 to May 2004, collecting on each occasion all the plants with mines found in an area delimited by a 0.28m2 ring thrown in the lines and between the lines of 30 randomly chosen trees. In the lab, the number of larvae and pupae per leaf of leafminers were recorded. The leaves were maintained until emergence of leafminers or parasitoids. Counting revealed 11 species of Lepidoptera leafminers of the families Gracillariidae, Acrolepiidae, Nepticulidae and Tischeriidae; 15 species of leafminer host plants of 9 families, and 12 species of hymenopteran parasitoids of the families Eulophidae and Braconidae. The leafminers larvae and pupae presented a negative association with temperature and air relative humidity. P. citrella was not observed in the spontaneous plants. Parasitoid species included in the genera Chrysocharis, Closterocerus, Sympiesis and Bracon have been previous reported as parasitizing P. citrella in several countries, and could be possible agents of biological control of this insect in the study area.

KEY WORDS
Insecta; Hymenoptera; biodiversity; natural enemies; population dynamics

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