Thirty-five species of chiggers, including 20 new, are recorded. New species and their type hasts are: Whartonia trinidadeusis off Mormoops megalophylla (leaf-chinned bat), Euschongastia anops off Chilonycteris rubiginosa (mustached bat), Eus. downsi off Didelphis marsupialis (opossum), Eus. flochi off Rattus rattus (black rat), Eus. lipoglena off Mormoops megalophylla, Eus. megastyrax off Desmodus rotundus (vampire bat), Speleocola secunda off Micronycteris hirsuta (hairy big-eared bat), Trombicula aitkeni off Nectomys squamipes, T. carmenae off Phyllostomus discolor (spear-nosed bat), T. discors off Mormoops megalophylla, T . fragibarba off Amazona amazonica (Amazon parrot), T. longicalcar off Amazona amazonica, T. macrozota off Mormoops megalophylla, T. manueli off Zygodontomys brevicauda (short-tailed cane rat), T. merga off Amazona amazonica, T. monops off Mormoops megalophylla, T. paragoga off Nectomys squamipes, T. pecari off Pecari tajacu, (collared peccary) from Chiriqui, Panama, T. saccopteryx off Saccoptelyx bilineata (greater white-lined bat), T . vesperuginis off Artibeus jamaicensis (Jamaican fruit bat). A key to species is given and a classified list of hasts and their chiggers appended. T. landazuri Boshell and Kerr and T. canis Floch and Abonnenc are sunk as synonyms of T. dunni Ewing. Additional description and-or figures are given for T. dunni Ewing,T. punctata Boshell and Kerr, T. sinnamaryi Floch and Fauran, and Eus. colombiae Boshell and Kerr.