PLANT ARCHITECTURE AND GALL ABUNDANCE ON TWO PLANT SPECIES FROM RESTINGA, RJ, BRAZIL

Abstract

Several hypotheses have been proposed to explain the distribution pattern and abundance of herbivorous insects on its host plants. For example, the plant architecture hypothesis predicts that variation in host plant architecture influences insect herbivore community structure, dynamics and performance. This study aimed to test the plant architecture hypothesis and its relation with gall abundance on two Brazilian endemic plant species, Clusia lanceolata (Clusiaceae) and Monteverdia obtusifolia (Celastraceae) in Marica Restinga, Rio de Janeiro. Plant architecture and gall abundance were directly recorded on 30 individuals from each plant species. Plant height, soil height circumference, number of second and third level ramifications, treetop area, plant volume, and leaf number were all used as predicting variables of gall abundance. A total of 922 insect galls were registered on C. lanceolata and 1.139 on M. obtusifolia . Variations on plant architecture did not explain gall abundance for both plant species. Results can be explained the plastic potential of the species studied. In this sense, the morphological changes in C . lanceolata and M. obtusifolia caused by the galls may have been buffered to maintain the vigor of the species. The difference between the variables in relation to gall abundance indicates that species studied can tolerate and minimize the presence of galling insects, revealing a high capacity for homeostasis in the face of biotic stress.