Additions to the taxonomy of New World Pheidole (Hymenoptera: Formicidae). Longino, J. T. Zootaxa 2009 2181 1 90 urn:lsid:biosci.ohio-state.edu:osuc_concepts:182016 Insecta Formicidae Pheidole CoL Animalia Pheidole boltoni Wilson Hymenoptera 17 Arthropoda species boltoni   Pheidole boltoni Wilson, 2003: 666, figs. Holotype major worker and associated paratype minor worker: Costa Rica, Heredia, 8km N Volcan Barba, 10°12'N 84°06'W, 1830m, 4-14 Jul 1986 (Longino #1329) [ MCZ] (examined).  Pheidole humida Wilson, 2003: 614, figs. Holotype major worker and associated paratype minor worker: Costa Rica, Puntarenas, Monteverde, 1550m, 20 May 1979 (P. S. Ward #3450) [ MCZ] (examined). New synonymy.  Geographic Range Costa Rica.  Biology This species is a montane cloud forest specialist. In the tropics ant abundance declines dramatically between 1500m and 2000m and ants are very difficult to find above 2000m. Pheidole boltonioccurs in a narrow band at the very upper edge of ants' natural occurrence. Several nests have been collected under epiphyte mats in recent branch and treefalls. One nest (the types of P. humida) was collected in a rotten log.  Comments The types of P. humidaare very similar to types and additional material of P. boltoni, differing only in having a lighter color. Multiple collections of P. boltonihave been made at the peak of Volcan Barba in the Cordillera Volcanica Central. The type series of P. humidawas collected in Monteverde, in the Cordillera de Tilaran. Oddly, no other material has been collected from Monteverde, in spite of intensive collecting there.