INSECT SOCIETIES II - ANTS

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READ: T&J  chap 4, 79.  Film: Army Ants

REFERENCES:

Agnosti, D. et al.. 1998. Oldest known ant fossils discovered. Nature. 391: 447-.

Handel, S. and A. Beattie. 1990 August. Seed dispersal by ants. Sci. Am. 263(2): 76

Holldobler, B. and E. Wilson. 1977 Dec. Weaver ants. Sci. Am. 237(6): 146

Holldobler, B. and E.O. Wilson. 1990.The Ants. Cambridge. Harvard Univ. Press.ON RESERVE

Holoway, D. et al. 1998. Loss of interspecific aggression in the success of a waidespread invasive social insect. Science 282: 949-952.

Hoyt, Erich. 1996. The Earth Dwellers: Adventures in the Land of Ants. New York. Simon & Schuster. 319pp. ON RESERVE

Lenczewski, B. 1987. Natural history, colonization, and survival in a northern fungus-gardening ant, Trachymyrmex septentrionalis (Attini). Thesis, Florida State Univ.

Mueller, U. et al. 1998 The evolution of agriculture in ants. Science 281: 2034-2038. (see comment on p. 1974, same issue)

Schmid-Hempel, P. 1999. Parasites of Social Insects. Princeton. Princeton U P. 409pp.

Tschinkel, W. 1998. The reproductive biology of fire ant societies. Bioscience. 48: 593-606.

Wilson, E.O. 1975 Jun. Slavery in ants. Sci. Am. 232(6): 32

Wilson, E.O. 1987. Causes of ecological success: The case of ants. J. of Animal Ecol. 56: 1-10

Colony formation and structure in ants

Myrmecia - primitive, semiclaustral nest founding

queen hunts like wingless solitary wasp to feed first brood

workers also hunt alone

higher ants - claustral nest founding

queen feeds first brood on fat body and wing muscles

workers may forage cooperatively

mass nuptial flights; queens found new colonies (usually)

some colonies reproduce by fissioning - army ants

some species have multiple queens - fire ants

workers may also lay eggs in some forms

Ant’s occupation of unique adaptive zones (Wilson 1987)

Fungus growing - Attini; Atta colonies convert huge amounts of fresh vegetation into fungus

Swarm raiding, army ants & driver ants - Dorylinae and Ecitoninae

Herding of aphids, treehoppers etc.

Several genera depend largely on these symbionts

keep treehopper nymphs in nest overwinter

Diabolus cuspidatus (Maylasia) move pseudococcids between feeding sites and nests in a shifting pattern

Social parasitism

temporary parasites - queens take over nest of another species

dulosis - workers raid other nests for pupae that become slave workers

inqulinism - few or no workers, queen lives in nest of another species

Ant success

As much as 20% of animal biomass in tropical forests

Range from arctic circle to Tierra del Fuego: four genera, including Camponotus and Pheidole occupy almost whole range

Genera long-lived in geologic record - back to Cretaceous

Ants first group of eusocial predatory insects to occupy litter & soil as habitat

Cooperative organization of colonies

workers can forage alone or recruit nestmates with chemical signals

trail and alarm pheromones

workers can specialize on one step in a complex task

trophallaxis insures all workers fed on available resources

Anatomical specialization

mandibles may be modified into special tools

lack of wings facilitates occupation of soil

metapleural gland secretes substances that may help suppress microbes

useful in soil/litter

unique in ants

secondarily lost in some arboreal groups

Ants share success of other advanced eusocial groups - bees, wasps, termites together may comprise 75% of insect biomass in Amazon forest