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B Hölldobler

Publications and source records attributed to B Hölldobler.

30 records · Page 2Linked to original sources
PubMed1995

Reproductive cooperation between queens and their mated workers: the complex life history of an ant with a valuable nest.

The life history of Harpegnathos saltator is exceptional among ants because both queens and workers reproduce sexually. Recently mated queens start new colonies alone, but later some of the offspring workers also become inseminated and take over the egg-laying role. This alternation seems associated with the existence of very complex underground nests, which are designed to survive floods. Longevity of ponerine queens is low (a consequence of limited caste dimorphism in this "primitive" subfamily), and upon the death of an H. saltator foundress, the nest represents a substantial investment. The queen's progeny should thus be strongly selected to retain the valuable nests. Unlike the flying queens, the workers copulate with males from their own colonies, and, thus, their offspring are expected to be highly related to the foundress. Colony fission appears not to occur because a daughter fragment would lack an adequate nest for protection. Thus, the annual production of queens in colonies with reproductive workers remains essential for the establishment of new colonies. This contrasts with various other ponerine species in which the queens no longer exist.

Journal Article↗
PubMed1995

The chemistry of social regulation: multicomponent signals in ant societies.

Chemical signals mediating communication in ant societies are usually complex mixtures of substances with considerable variation in molecular composition and in relative proportions of components. Such multicomponent signals can be produced in single exocrine glands, but they can also be composed with secretions from several glands. This variation is often functional, identifying groups or specific actions on a variety of organizational levels. Chemical signals can be further combined with cues from other sensory modalities, such as vibrational or tactile stimuli. These kinds of accessory signals usually serve in modulatory communication, lowering the response threshold in the recipient for the actual releasing stimulus. Comparative studies suggest that modulatory signals evolved through ritualization from actions originally not related to the same behavioral context, and modulatory signals may further evolve to become independent releasing signals.

Animal Communication↗
PubMed1993

Fighting for a harem of queens: physiology of reproduction in Cardiocondyla male ants.

Several species of the ant genus Cardiocondyla produce dimorphic males, which exhibit sharply different mating strategies. Winged males typically disperse to mate outside the nest, whereas wingless, ergatoid males stay in the nest and aggressively employ their mandibles against competing ergatoid males to monopolize the virgin queens eclosing in the nest. Such aggressive mating strategy would only be adaptive if the males had unlimited sperm supply. Histological studies showed that, contrary to the rule in the Hymenoptera order, the ergatoid Cardiocondyla males are indeed able to produce sperm during their entire adult life. Winged males, on the other hand, have only a limited sperm supply since spermatogenesis ceases in the late pupal stage.

Journal Article↗
PubMed1980

Sex differences in cooperative silk-spinning by weaver ant larvae.

Final-instar larvae of weaver ants (Oecophylla longinoda) use their silk for nest construction rather than for cocoon spinning; this commitment represents a shift from entirely selfish to entirely cooperative behavior that occurred after the emergence of the phylogenetically advanced subfamily Formicinae. Male larvae were found to have smaller silk glands and to contribute substantially less silk to nest construction. The hypothesis of kin selection appears to be the most plausible and parsimonious explanation of this sex difference, but other, individual-level modes of selection have not been eliminated.

Journal Article↗
PubMed1977

Weaver ants: social establishment and maintenance of territory.

Workers of the African weaver ant Oecophylla longinoda recruit nestmates to previously unoccupied space by means of odor trails laid from the rectal gland, a hitherto unrecognized musculated organ located at the rear of the rectal sac. When enemy ants and other intruders are encountered on the territory, the Oecophylla assemble nestmates into small resting clusters by dispensing an attractant-arrestant pheromone from the sternal gland, a second newly discovered organ located on the last abdominal sternite. Under prolonged stress, additional forces are recruited to the combat area with the aid of the rectal-gland trail substance.

Abdomen↗
PubMed1977

Sexual calling behavior in primitive ants.

The wingless virgin females of the ponerine ant Rhytidoponera metallica attract males by the release of a pheromone from the tergal gland, a hitherto unrecognized exocrine gland located between the last two abdominal segments. This is the first evidence for sexual chemical communication in the large and primitive subfamily Ponerinae.

Animals↗
PubMed1977

Colony-specific territorial pheromone in the African weaver ant Oecophylla longinoda (Latreille).

Major workers of Oecophylla longinoda mark their territories with persistent pheromones that are distinguishable to the ants at the colony level. Workers detecting the deposits of an alien colony respond with increased amounts of aversive and aggressive behavior, and they later recruit nestmates to the area at a higher rate. Colonies entering a field impregnated with their own scent also gain an initial advantage in warfare with other colonies. The pheromones are located at least in part in drops of rectal sac fluid deposited by workers over the territorial surface.

Animals↗
PubMed1974

Tandem calling: a new kind of signal in ant communication.

Leptothorax acervorum, L. muscorum, and L. nylanderi recruit nest mates to a new food source by tandem running, with only one nest mate being recruited at a time. This technique is initiated by a special "tandem calling" behavior; the recruiter slants its gaster upward and discharges poison gland secretions from the extruded sting. Nest mates are attracted, and as soon as one of them touches the calling ant, tandem running starts. Further details of the full recruitment sequence are provided. Evidence is presented to suggest that tandem running is the evolutionary precursor of odor-trail communication and sex attraction within certain phylogenetic lines of myrmicine ants.

Animals↗
PubMed1974

Home range orientation and territoriality in harvesting ants.

Trunk trails, used by Pogonomyrmex barbatus and P. rugosus during foraging and homing, have the effect of avoiding aggressive confrontations between neighboring colonies of the same species. They channel the mass of foragers of hostile neighboring nests into diverging directions, before each ant pursues its individual foraging exploration. This channeling subtly partitions the foraging grounds and allows a much denser nest spacing pattern than a foraging strategy without trunk trails, such as that employed by P. maricopa.

Journal Article↗
PubMed1971

Homing in the harvester ant Pogonomyrmex badius.

During homing, the harvester ant Pogonomyrmex badius orients both to the sun and to chemical cues. Visual patterns are generally the less important. Trails laid from the secretion of Dufour's gland comprise the main chemical homing signal. This orientation mechanism assists foraging workers to return precisely to their own nests even when the nest populations are dense.

Animals↗