Efforts at classical biocontrol for M. faya were begun in the mid 1950s, and have continued sporadically, with exploratory excursions by entomologists from Hawaii to its native habitats: the Azores, Madeira, and the Canary Islands in the North Atlantic. More recently, plant pathologists, including myself, have made similar excursions to these regions in search of plant pathogens as possible biocontrol agents.
Myrica faya in a botanical garden on the island of Sao Miguel, the Azores.
M. faya (dark vegetation) growing on a hillside (left) and on a seacliff (right) on the island of Faial, Azores. The specific name faya is thought to have been derived from the name of this island.
Young, vigorous M. faya growing as an understory in a plantation of introduced pines, island of Faial.
As demonstrated in Hawaii, M. faya has the ability to colonize recent lava. Like Hawaii, the Azores are of volcanic origin, and volcanism is ongoing in both archipelagoes. A dense stand of M. faya is shown here colonizing a recent lava flow (dark vegetation) on Faial.
In its native habitat, shown here on the island of Pico, M. faya may grow in dense, mixed forest stands of native trees, collectively termed "laurosilva". In such associations, trees are straight and spindly, producing branches and foliage only at the top of the canopy.
M. faya frequently is found as a re-invader of old pastureland, where it occurs in open stands, as shown here on upper slopes of the island of Pico.
Whereas most of the trees of M. faya observed in its native habitats were small to midsized, we occasionally found rather large individuals. The tree shown here, on the island of Gomera in the Canary Islands, was perhaps the largest found.
The lands of lower elevations of the Azores are heavily utilized for agriculture, although much of the land is rocky. Rocks are often gathered and used to form barriers between small fields, or vinyards, such as shown on the island of Pico (left). We found M. faya frequently invading such areas, both under active cultivation and abandoned. Islands of Faial (middle), and Sao Miguel (right).
The island of Pico from Faial.
The island of Madeira, south of the Azores, is mountainous and rugged. The mountainsides are cultivated, often through the use of a well-developed system of terraces, where small crops, particularly potatoes, are grown. M. faya occurs throughout the native forests, and in forest remnants. It is found in and around the agricultural terraces and in other sites not actively cleared for cultivation.
The Canary Islands:
The Canary Islands are situated off the western coast of Africa, and are the southern-most archipelago upon which M. faya occurs naturally. The climate of the Canaries is warmer and drier than that of the Azores or Madeira. An abundance of M. faya was found in the Canaries, particularly in those regions, such as on the island of Gomera, where the native vegetation had not been severely displaced by agriculture or development. Because of the mountainous terrain, an elaborate system of terracing has been developed for agriculture, as it has in Madeira.