Preferences and differences in the trail pheromone of the leaf-cutting ant Atta sexdens sexdens (Hymenoptera: Formicidae)

Abstract

Abstract. The amount of the trail pheromone substance, 3-ethyl-2,5-dimethylpyrazine, of the leaf-cutting ant Atta sexdens sexdens (Hymenoptera: Formicidae) increases with increasing size of the ant from 0 to 35 ng per individual. The compounds 2,5-dimethylpyrazine and trimethylpyrazine are also consistently present. Trails of venom gland extracts are followed with unequal fidelity by different castes. Minor workers follow best, mediums least well. Workers walk sinuously on narrow trails and less sinuously on wider trails up to 9 mm. Trails wider than 9 mm are not followed. The optimum concentration of pheromone on synthetic trails lies between 15 and 150 pg cm -1. Given a choice of concentrations at a trail branch, workers always choose the more concentrated. Workers showed slight preference for a trail made with venom gland secretion from their own, over that from an alien colony, but there is no preference for a trail that contains Dufour gland secretion additionally.

Distinct antennal lobe phenotypes in the leaf‐cutting ant (Atta vollenweideri)

“…Behavioral analysis of bumble bees show that the antennal sensitivity to odors increases with body size (Spaethe et al, 2007). Large leaf-cutting ants have a higher trail fidelity than small workers (Morgan et al, 2006), and in a behavioral study we found workers with MG to be more sensitive to the releaser component of the trail pheromone (unpublished data).…”

“…In particular, M4MP2C and also the second main component 2E3,6DMP of the trail pheromone are found in relatively high quantities in the poison gland secretion of several Atta species (Morgan, 2009). The ratio of both defines species specificity (Evershed and Morgan, 1983;Morgan et al, 2006). Interestingly, 2E3,6DMP is represented in at least one glomerulus further toward the midline but adjacent to the MG. A closely related Atta species (A. sexdens) uses 2E3,6DMP as releaser component of the trail pheromone.…”

Density of mushroom body synaptic complexes limits intraspecies brain miniaturization in highly polymorphic leaf-cutting ant workers

“…By contrast, mini workers are specialized in the maintenance of brood and fungus inside the nest, although they can also be found outside the nest on the trails [36,54–56]. Furthermore, it was shown that large workers have higher trail fidelity than mini workers [57]. The differences in pheromone trail following behaviour are reflected in the AL structure.…”

Argentine Ant Trail Pheromone Disruption is Mediated by Trail Concentration

“…We used the approach reported by Suckling et al (2008), based on the parallel trails used by Morgan et al (2006), of a suspended horizontal glass plate (400×200×5 mm) as the substrate. This was connected by a single wire at one diagonal end to channel and regulate the foraging of an ant between nest and food source.…”