The Puerto Rican Pygmy, Cyrtopholis portoricae is the most common species of tarantula in Puerto Rico. Although it is called a "pygmy", they are medium-sized terrestrial tarantulas that live in burrows digged on the ground, where they can be found during the day. This species has a dark brown with light rosy stripes on each leg. Some people regard them as extremely aggressive, this is exagerated. They will defend themselves if provoked or if they feel threathened.
Another uncommon species is the arboreal, Trichopelma corozali an endemic species which
also has the ability to climb; during the day they dwell in burrows excavated on tree trunks or among the roots. As you can see on the photo on the left, these hideouts and the entrance are covered with silk. The second photo was taken on the trail to Mt. Britton at the El Yunque National Forest (formely known as the Caribbean National Forest) after the spider emerged from its burrow during the night. It can be easily identified by just looking at the abdomen with dark-grey or black hairs.
Avicularia laeta, or the Puerto Rican Tree Tarantula, is also an endemic species to the Greater Puerto Rican Region. Unlike other tarantulas, this species is adapted to an arboreal lifestyle, because they possess under the distal portion of the legs made of microscopic hooks; this allows
them to walk over branches and leaves. It builds silk nests in holes in tree-trunks or in the crevices of large boulders and at limestone cliffs. They can also build their nests in the central rosettes of some species of bromeliads, as you can observe on the photo on the right. This photo was taken at St. John, U.S.V.I; the first two were taken at the University of Puerto Rico, Humacao.
Pepsis vs Holothele
One the most remarkable natural events, is the relationship between the wasp, Pepsis ruficornis (first photo at the end) and the tarantula, Holothele sp. The female wasp actively looks for a tarantula; when one is found, she stings the tarantula, and then with her antennae determines if is the right species. The wasp next digs a hole where she will bury the spider and then lays one egg next to it. After it hatches, the larvae will be nourished by slowly eating the spider, keeping it alive by saving the vital organs for last. In the last two photos you can observe the wasp in pursuit and when it tries to sting the small tarantula. The outcome... the predator not always win.