Study of Host-Parasite Relationship among Loranthaceae Flowering Shrubs Myrmecophytic Fruit Trees-Ants in Logbessou District, Cameroon.

The objective of this study is host-parasite relationship among Loranthaceae flowering shrubs, Myrmecophytic fruit trees and ants. The study was conducted in 2009 in the garden plots and orchards of houses in the Logbessou district of Douala, Cameroon. We inventoried a total of 141 myrmecophytic fruit trees (diameter ≤ 45 cm) of which 95 (67.3%) were parasitized by flowering-shrub epiphytes (Loranthaceae). These trees belong to 14 species, 11 genera and 8 families. Among the eight species of ants inventoried on the trees, two were arboreal-dwelling and six were ground-dwelling, arboreal-foraging species. They belonged to two sub-families: the Formicinae, which were mostly represented by two genera, Camponotus and Paratrechina; and the Myrmicinae, which were more abundant (87.5%). The ants nested in the domatia of myrmecophyte hosts or hollow branches, trunks and dead suckers of Loranthaceae. Crematogaster was the most frequent genus and dominant ant on all of the parasitized host trees.

Resposta da comunidade de formigas aos atributos dos fragmentos e da vegetação em uma paisagem da Floresta Atlântica nordestina / Response of the ant community to attributes of fragments and vegetation in a northeastern Atlantic Rain Forest area, Brazil

The objective of this study was to determine the effects of forest fragmentation on ant richness in a landscape of Atlantic Forest in Northeast Brazil. More specifically, the ant richness was related to the attributes of fragments (area and distance from the fragment central point to the edge), landscape (forest cover surrounding the fragments), and tree community (plant density, richness, and percentage of shade tolerant species). The surveys were carried out in 19 fragments located in Alagoas State from October 2007 to March 2008. Samples were collected through a 300 m transect established in the center of each fragment, where 30 1-m² leaf litter samples were collected at 10 m intervals. A total of 146 ant species was collected, which belonged to 42 genera, 24 tribes and nine subfamilies. The attributes of fragments and landscape did not influence ant richness. On the other hand, tree density explained ca. 23 percent of ant richness. In relation to functional groups, both density and richness of trees explained the richness of general myrmicines (the whole model explained ca. 42 percent of the variation in this group) and percentage of shade tolerant trees explained the richness of specialist predator ants (30 percent for the whole model). These results indicate that ant fauna is more influenced by vegetation integrity than by fragment size, distance to edge or forest cover surrounding fragments.