Ant Association with Parinari excelsa (Chrysobalanaceae) in Marajo, Brazil

Abstract

The field notes in herbaria for many species of Patinari often state that these trees are full of ants or ant nests. For example, ants make nests by weaving together the curved margins of the leaves of Parinari alvimii Prance (fide S. Mori, F. Benton & I. White collecton N? 10243) in Bahia, Brazil. On a recent trip to Marajo Island in the Amazon delta, I observed that about 150 trees (almost every tree) of Parinari excelsa Sabine, growing along the banks of the Rios Anajas and Moco6es, were inhabited by ants and full of unusual looking ant nests made of a brown, woolly substance. An examination of the nests and observations of the tree leaves showed that the nests are constructed out of a brown, woolly indumentum that covers the lower surfaces of the young leaves of P. excelsa. In heavily ant-infested trees most of the new leaves had been harvested by these ants, identified as Hypoclinea sp. in the subfamily Dolichoderinae by Dr. Roy Snelling. They gather the hair by scraping it from the leaves and then carting it off in large bundles, using their mandibles. The older nests are up to 1.5 m in size, and most trees also have smaller nests along the branches (Fig. 1). Ant nests were not observed in species other than P. excelsa. A brief note by Sefer (1957) refers to ant nests made of an unknown cottony substance being collected from trees of Parinari montana Aubl. in the Tembe Indian reservation on the Rio Guama in Para. He observes that: "The branches and leaves were impregnated with a spongy substance that is much used by the Indians and which is called, inappropriately by some people, ant cotton (algodao de formiga)." The ants in this case were identified as Dolichoderus mucronifer Roger, also in the subfamily Dolichoderinae. Sefer thought that the spongy nest material was secreted by the ants. He observed that the nest material is difficult to wet and easily flammable so the Indians use it as a wick material. They also use it as a starting material when they light fires by the heat of friction in the traditional manner of spinning one