Sperm length, sperm storage and mating system characteristics in bumblebees B. BaerP. Schmid-HempelJ. J. Boomsma Research Article Pages: 101 - 108
Spatial differences in worker policing facilitate social parasitism of Cape honeybee workers (Apis mellifera capensis Esch.) in queenright host colonies P. NeumannC. W. W. PirkR. F. A. Moritz Research Article Pages: 109 - 112
Lack of patriline-specific differences in chemical composition of the metapleural gland secretion in Acromyrmex octospinosus D. Ortius-LechnerR. MaileJ. J. Boomsma Research Article Pages: 113 - 119
Spatial patterns of seed predation by harvester ants (Messor Forel) in Mediterranean grassland and scrubland F. M. AzcárateB. Peco Research Article Pages: 120 - 126
The organisation of larval feeding in bumblebees (Hymenoptera, Apidae) and its significance to caste differentiation J. J. M. PereboomH. H. W. VelthuisM. J. Duchateau Research Article Pages: 127 - 133
Reproductive decisions by honey bee colonies: tuning investment in male production in relation to success in energy acquisition T. D. SeeleyA. S. Mikheyev Research Article Pages: 134 - 138
Sociobiology of hypogaeic army ants: characterization of two sympatric Dorylus species on Borneo and their colony conflicts S. M. BerghoffJ. GadauU. Maschwitz Research Article Pages: 139 - 147
The first record among Dolichoderinae (Formicidae) of parasitism by Strepsiptera D. P. HughesG. Moya-RaygozaJ. Kathirithamby Research Article Pages: 148 - 150
Nestmate discrimination in ants: effect of bioassay on aggressive behavior T. H. RoulstonG. BuczkowskiJ. Silverman Research Article Pages: 151 - 159
Annual and multi-year nests of the western yellowjacket, Vespula pensylvanica, in California P. K. VisscherR. S. Vetter Research Article Pages: 160 - 166
Altruistic defenders in a gall-forming aphid of the tribe Hormaphidini (Homoptera, Aphididae, Hormaphidinae) on its primary host H. ShibaoT. Fukatsu Research Article Pages: 167 - 173
Collective and individual nursing investment in the queen and in young and old honeybee larvae during foraging and non-foraging periods T. SchmicklB. BlaschonK. Crailsheim Research Article Pages: 174 - 184
Mitochondrial DNA and AFLP markers support species status of Apis nigrocincta D. R. SmithM. R. PalmerM. Damus Research Article Pages: 185 - 190
Finding its place in a competitive ant community: leaf fidelity of Camponotus sericeus K. ModyK. E. Linsenmair Research Article Pages: 191 - 198
Identification of polygyne and monogyne fire ant colonies (Solenopsis invicta) by multiplex PCR of Gp-9 alleles S. M. VallesS. D. Porter Short communication Pages: 199 - 200