Atta cephalotes

It is conceivable that such rather unspecific modulatory signals obtain more specific significance in the communication process. A striking example is that of the leaf-cutter ant Atta cephalotes (24). 

The leaf cutter ant Atta cephalotes, which cultivates a fungus as food, produces compounds that increase the growth of the fungal food and compounds that block the germination of undesired fungal spores,... 

Okunade and Wiemer reported isolation of a potent ant-repellent compound, (-)-loliolide (Fig. 7) from Xanthoxyllum setulosum. The plant is one of the many native Costa Rican plants found to escape attack of the highly polyphagous leafcutter ants Atta cephalotes. Additional leafcutter ant repellent constituents have been isolated from Piper tuberculatum ... 

Of the three compounds isolated, piplaroxide and demethoxypiplartine (Fig. 7) demonstrated significant activity in a laboratory bioassay measuring repellency to the leafcutter ant Atta cephalotes. 

Leaf cutter ants, abundant from Texas to Argentina are polyphagous herbivores, but will not attack several plants. The ant, Atta cephalotes, for example, does not feed on Lasianthaea fruticosa (Asteraceae). The active repellent substance has been demonstrated to be lasidiol angelate (8p. 

Mueller, U. Wolf-Mueller, B. "Epiphyll Deterrence to the Leafcutter Ant Atta cephalotes , Oecologia, 1991, 59, 615-625. 

P-Ocimene (47) is a repellent to die leaf cutter ant Atta cephalotes in both field and laboratory experiments (Har-bome, 1987). Experiments with the aphid Cavariella aego-podii, which feeds on umbellifer species in summer, indicate that the aphid can be captured in traps baited with carvone (48), but are repelled by linalool (6) (Chapman et al., 1981 Harbome, 1987). Carvone occurs in the essential oils of several plants of the Apiaceae. 

Leaf cutter ants, abundant from Texas to Argentina, are polyphagous herbivores, but will not attack several plants. The ant, Atta cephalotes, for example, does not feed on Lasi-anthaea fruticosa (Asteraceae). The active repellent substance is lasidiol angelate (51) (Wiemer and Ales, 1981). Three of four other inhibitory compounds to ant feeding, nerolidol (7), caryophyllene epoxide (52), kolavenol (a diter-pene), and caiyophyllene (not active), either produced dramatic effects on the ants or the fungus cultivated by the ants (Howard et al., 1988). 

Jacquinonic acid (75) from Jacquinia pungens (Theophrastaceae) inhibits feeding by the leafcutter ant Atta cephalotes. As this compound is nonvolatile, tactile contact by the ant is probably necessary for sensing the presence of this triterpene. A mixture of triterpenoids from Cordia alliodora (Boraginaceae) similarly prevents feeding by tiiis ant (Harbome, 1987). 

Jaffe, K., Bazire-Benazet, M. and Howse, P. E. (1979) An integumentary pheromone-secreting gland in Atta sp territorial marking with a colony-specific pheromone in Atta cephalotes. J. Insect Physiol., 25, 833-9. 

A more sophisticated system is available to the leaf-cutting ant Atta cephalotes... 

Bradshaw, J. W. S., Howse, P. E. and Baker, R. (1984) A novel pheromone regulating chain transport of leaves in Atta cephalotes. Animal Behaviour (in press). 

Riley, R. G., Silverstein, R. M., Carroll, B. and Carrol, R. (1974b) Methyl 4-methyl-pyrrole-2-carboxylate a volatile trail pheromone from the leaf-cutting ant, Atta cephalotes. J. Insect Physiol., 20, 651-4. 

---