Previously, the genus Leptopholcus was thought to be largely restricted to the Old World. All New World records were from the Antilles, where these spiders are quite common. Recently, three species of the genus have been found in South America: two in Brazil and one in Venezuela. Why is it so rare on the mainland? The answer lies probably in another genus that occupies exactly the same microhabitat (the underside of large leaves): Metagonia is common on the mainland but absent from the Antilles (except one cave in Cuba).
In the meantime, morphological and molecular evidence has led us to transfer all New World Leptopholcus to Micropholcus (see Huber et al. 2014).
Photos: B. A. Huber