Identification of the Trail Pheromone of a Leaf-cutting Ant, Atta texana

Electroantennograms (EAGs) were recorded from major workers, queens, and males of the Texas leaf cutting, Atta texana (Buckley) (Hymenoptera: Formicidae) in response to serial dilutions of two alarm substances, 2-heptanone and 4-methyl-3-heptanone, and its trail pheromone, 4-methylpyrrole-2-carboxylate. The lower EAG threshold for major workers relative to queens and males for both alarm substances correlated well with previously reported behavioral bioassays which showed workers to be most responsive to these odorants. Although laboratory behavioral bioassays showed minor workers, queens, and males to have a similar behavioral threshold for the trail pheromone, minor workers were more responsive to higher concentrations of the trail pheromone. However, EAGs revealed queens significantly more sensitive and responsive to the trail pheromone than the other castes. These seemingly enigmatic results are discussed with regard to A. texana biology and receptor physiology.

Download Full-text

The possible use of methyl 4-methylpyrrole-2-carboxylate, an ant trail pheromone, as a component of an improved bait for leaf-cutting ant (Hymenoptera: Formicidae) control

Bulletin of Entomological Research ◽

10.1017/s0007485300007240 ◽

1978 ◽

Vol 68 (1) ◽

pp. 159-170 ◽

Cited By ~ 14

Author(s):

S. W. Robinson ◽

J. M. Cherrett

Keyword(s):

Trail Pheromone ◽

Nest Entrance ◽

Acromyrmex Octospinosus ◽

Atta Sexdens ◽

Citrus Pulp ◽

Single File ◽

Atta Texana ◽

Leaf Cutting ◽

High Concentrations ◽

Ant Trail

AbstractA trail pheromone, methyl 4-methylpyrrole-2-carboxylate (M4MP2C), of Atta texana (Buckley) was tested in the laboratory as a possible component of attractive poison bait for the leaf-cutting ants A. cephalotes (L.), A. sexdens (L.) and Acromyrmex octospinosus (Reich). For all three species, M4MP2C when impregnated onto paper discs increased pick-up of the discs. It also increased pick-up by Atta sexdens of a citrus-pulp bait. The addition of M4MP2C made them easier to find, although at high concentrations it was repellent. It did not affect the average number of ant investigations before the bait was picked up. The pheromone remained on citrus-pulp bait in active concentrations for approximately four days. To test -the effect of M4MP2C as a foraging stimulant for A. cephalotes, an apparatus was constructed in which the ants passed in single file over a transparent section of the trail where they were counted with a photoelectric cell. When bait impregnated with M4MP2C was placed on the foraging table, large increases in activity were recorded away from the nest but only small increases were recorded in the nest and at the nest entrance. When air containing M4MP2C vapour was injected into the fungus chamber, an increase in activity was recorded at the nest entrance, but this increase was not repeated when known amounts of the pheromone impregnated onto baits of filter-paper discs were added directly to the fungus chamber. It is suggested that factors other than M4MP2C are also involved in the stimulation of foraging activity. The experiments suggest that M4MP2C could play some part in the formulation of an attractive bait for the control of leaf-cutting ants.

Download Full-text