Caetetermes taquarussu Fontes (Isoptera, Termitidae, Nasutitermitinae): description of the imago caste and new distributional records.

Caetetermes Fontes, 1981 is a monotypic South American genus of Nasutitermitinae. Its single species, Caetetermes taquarussu Fontes, 1981, was described based on morphological characters from soldiers and workers collected at three localities in the tropical rainforest of northeastern Ecuador. Several samples of C. taquarussu represented also by the imago caste were examined at the Museu de Zoologia da Universidade de São Paulo, São Paulo, Brazil (MZUSP) and the National Museum of Natural History, Washington D.C., USA (USNM). Herein, we describe the imago caste of Caetetermes for the first time, with notes on soldier and worker caste and new distributional records for the species. We use the terminology of Fontes (1987) for worker mandibles, and Noirot (2001) for the digestive tube of workers. We took the measurements with a micrometric reticle in the eyepiece of a stereomicroscope Leica MZ6 for the following morphometric characters (Roonwal 1970): imagoes, LH, length of head capsule (9); WH, width of head capsule without eyes (18); OF, occipito-fontanelle distance (23); LF, length of fontanelle aperture (26); DE, diameter of eye (48); LO, length of ocellus (55); WO, width of ocellus (56); EOD, eye-ocellus distance (57); LP, length of pronotum (65); WP, width of pronotum (68); soldiers, LH, length of head with nasus (12); WH, width of head capsule (18); HH, height of head excluding postmentum (21); WP, width of pronotum (68); LHp, the maximum length of the head capsule to the postclypeus was measured in profile as the distance between two parallels marking the hindmost margin of the head capsule and the apex of the postclypeus; workers, LH, length of head (9); WP, width of pronotum (68); all castes, LT, length of hind tibia (85). Left mandible index (LMI) as in Emerson (1960). We photographed C. taquarussu with a Canon S5IS digital camera mounted on a Leica MZ95 stereomicroscope, and the gizzard and the enteric valve under a microscope Leica DM500B attached to a video camera Leica DFC 295. Images were combined with Helicon Focus 5.2.11 X64. We mapped the published records (Krishna et al. 2013) and the locality data for the samples examined with Quantum GIS 1.7.0.