Harvester ants

They think locally and act locally, but their collective action produces global behavior. Take the relationship between foraging and colony size. Harvester ants constantly adjust the number of ants actively foraging for food, based on a number of variables overall colony size (and thus mouths needed to be fed) amount of food stored in the nest amount of food available in the surrounding area even the presence of other colonies... 

Mirex was first synthesized in 1946 but it was not introduced as a pesticide against hymenopterous insects, especially ants, until 1959 (Smith, 1991). Technical grade mirex consists of approximately 95% mirex and less than 2.5% chlordecone, mostly kepone (Eisler, 1985). Mirex is a stomach insecticide with little contact activity. The main use of mirex was against the imported fire ants in the south-eastern United States (WHO, 1984b). It has also been used to control leaf cutters in South America, harvester termites in South Africa, Western harvester ants in the United States, the pineapple mealy bug in Hawaii and it was proposed to have been used against yellow jacket wasps in the United States (WHO, 1995). Under the trade name of Dechlorane, mirex was used as a fire retardant in electronic components, fabrics, rubber, plastics and electrical goods (Eisler, 1985 WHO, 1995). 

Heredia A. and Detrain C. (2000) Worker size polymorphism and ethological role of sting associated glands in the harvester ant Messor barbarus. Insectes Soc. 47, 383-389. 

Holldobler B., Morgan E. D., Oldham N. J. and Liebig J. (2001) Recruitment pheromone in the harvester ant genus Pogonomyrmex. J. Insect Physiology. 47, 369-374. 

Wagner D., Tissot M. and Gordon D. (2001) Task-related environment alters the cuticular hydrocarbon composition of harvester ants. J. Chem. Ecol. 27, 1805-1819. 

Greene, M. J. and Gordon, D.M. (2007). Interaction rate informs harvester ant task decisions. Behav. Ecol., 18,451 155. 

Grasso, D.A., Sledge, M.F., Le Moli, F. Mori, A. and Turillazzi, S. (2005). Nest-area marking with faeces a chemical signature that allows colony-level recognition in seed harvesting ants (Hymenoptera, Formicidae). Insect Soc., 52, 36-44. 

Figure 12.1 Harvester ant foragers are stimulated to leave the nest in search of seeds in response to cues present in the task-specific cuticular hydrocarbon profile of patrollers. After inhibition of foragers at harvester ant colonies by removal of patrollers, colony foraging behavior was rescued by the addition of ant mimics, glass beads coated with task-specific cuticular hydrocarbons from patrollers, to the nest entrance at a rate of 1 bead every 10 seconds. Data were normalized to account for differences in the absolute number of foragers active each day. The same letters above bars denote statistical significance using a Tukey s post-hoc test. From Greene and Gordon, 2003.

Figure 12.2 Foraging activity at harvester ant colonies was affected by the simulated return rate of patrollers back to the colony. Letters above bars denote differences in statistical significance among treatments (LSD, p < 0.05). Error bars denote standard error of the mean. From Greene and Gordon, 2007a.

Gordon, D.M. (1989). Dynamics of task switching in harvester ants. Anim. Behav., 38, 194-204. 

Gordon, D. M. and Mehdiabadi, N. (1999). Encounter rate and task allocation in harvester ants. Behav. Ecol. Sociobiol., 45, 310-ill. 

Wagner, D., Brown, M. J.F., Broun, P., Cuevas, W., Moses, L.E., Chao, D.L. and Gordon, D. M. (1998). Task-related differences in the cuticular hydrocarbon composition of harvester ants, Pogonomyrmex barbatus. J. Chem. Ecol., 24, 2021-2037. 

Alkaloids have only been identified in the venoms of ant species in the Myrmicinae, the largest of the formicid subfamilies. This diverse subfamily includes fire ants and harvester ants, the species of which produce highly algogenic venoms. In addition, this ant taxon includes thief ants and... 

Amidinohydrazone insecticides contain an amidino [H2NC(=NH)-] and a hydrazone i R C=NNR2) group. Hydramethylnon is the only member of this class. It controls fire ants, harvester ants, big-headed ants, and cockroaches. 

Between 1961 and 1975, about 400,000 kg of mirex were used in pesticidal formulations, of which approximately 250,000 kg were sold in the southeastern U.S. for control of native and imported fire ants (Solenopsis spp.) most of the rest was exported to Brazil for use in fire ant control in that country. Mirex was also used to control big-headed ant populations in Hawaiian pineapple fields, Australian termites. South American leaf cutter ants. South African harvester termites, and, in the U.S., western harvester ants and yellow jackets. Chemical control measures for imported fire ants began in the southeastern U.S. during the 1950s with the use of heptachlor, chlordane, and dieldrin. The large mounds built by ants in cultivated fields were believed to interfere with mowing and harvesting operations, the vicious sting of the insects presented a hazard to workers... 

Black fire ant, Solenopsis richteri, 503 Harvester ant, Pogono myrmex, 797 Liometopum spp., 800 Red fire ant, Solenopsis invicta, 120, 303, 503,516... 

Well-documented studies of interference competition exist. Elimination of supernumerary larval parasitoids by physical attack of conspecifics is a dramatic case of direct interference by a competitor (Salt, 1961). Other examples include physical defense of territories by Pogonomyrmex harvester ants and Trigona bee species, and cannibalism in Tribolium beetles (Young, 1970) (see Section 11.5). Examples of indirect interference competition via chemical mediators have been found increasingly over the past decade (Prokopy, 1981a see also Section 11.5). 

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