We recently found exocrine glands in the antennae
of queens and workers of Solenopsis invicta and S. geminata
(Isidoro et al., Insectes Sociaux 47: 236, 2000). Antennal glands had not
been previously noted in a survey of antennae from about 50 ant species
(not including Solenopsis) (Hashimoto, Appl. Entomol. Zool. 25:
491, 1990). Therefore we wanted to know if antennal glands are unique to
Solenopsis, or if they are found in a wider taxonomic group. Using
SEM, we examined the antennae of 38 ant species. Presence of antennal glands
was indicated by a characteristic circumferential ring of pores in an antennal
segment of workers. Pores were found in the 9th antennal segment of all
species of Solenopsis examined (S. aurea, S. clytemnestsra, S.
corticalis, S. desecheoensis, S. electra, S. fugax, S. gayi, S. geminata,
S. globularia litoralis, S. interrupta, S. krockowi, S. latastei, S. macdonaghi,
S. molesta, S. molesta validiuscula, S. pergandei, S. picea, S. picta,
S. punctaticeps, S. quinquecuspis, S. richteri, S. tennesseensis, S. texana,
S. wasmannii emery, and S. xyloni). Pores were absent in the
following: Monomorium minimum, M. pharonis, Pheidole spp., Crematogaster
spp., Linepithema humile, Forelius spp., Dorymyrmex spp., Paratrechina
spp., Campanotus spp., Ectatomma ruidum, E. tuberlatum, and Pseudomyrmex
ferruginea. However, pores were found in the 12th antennal segment
of Tetramorium bicarinatum workers. This was the only non-Solenopsis
species examined which showed evidence for antennal glands.