Field evaluation of methyl 4-methylpyrrole-2-carboxylate, an ant trail pheromone, as a component of baits for leaf-cutting ant (Hymenoptera Formicidae) control

Abstract

In the laboratory, the trail pheromone methyl 4-methylpyrrole-2-carboxylate (M4MP2C) when added to bait particles acts as an attractant to leaf-cutting ants, increasing the pick-up of pheromone-impregnated bait compared with plain bait. However, field trials in Trinidad, Brazil and Paraguay were disappointing. Bait with and without pheromone was scattered in the foraging area, and the proportion of each taken to the nest by Atta sexdens rubropilosa Forel, A. cephalotes (L.) and Acromyrmex octospinosus (Reich) was assessed. In only one of the experiments (A. octospinosus foraging bait with 50 p.p.m. of M4MP2C) was increased pick-up detected. Four reasons for this are suggested: (1) small pheromone effects are difficult to measure as scattering bait produced a patchy distribution and heterogeneous replicates, whilst choice trials on plain and pheromone-impregnated bait placed close together were difficult to interpret, as the pheromone probably excited the ants, increasing pick-up of plain bait; (2) A. octospinosus workers, the subject of detailed studies, were less sensitive to M4MP2C in the field than in the laboratory; (3) as the pheromone only attracts, it does not produce a comparable increase in the number of pieces picked up, contact/pick-up ratios of sucroseimpregnated discs increasing from 2 26 at 5 pg pheromone to 16-39 at 50 ng; and (4) soyabean oil, citrus-pulp extract and orange juice were found to be attractive, and when pheromone was added, its effects were not additive. Early studies used sucrose-impregnated paper discs, and as these have no attractants of their own, the addition of M4MP2C had a more marked effect. It is concluded that M4MP2C is not a cost-effective addition to current leaf-cutting ant baits which possess food odours, a much cheaper source of attractiveness.

Pheromone performance as an attractive component in baits for the control of the leaf-cutting ant Atta sexdens rubropilosa Forel, 1908 (Hymenoptera: Formicidae)

“…When the pheromone was added to baits with food odour, its effect was not additive. Similar conclusions were obtained by ROBINSON et al (1982) working with M4MP2C and A. octospinosua.…”

Chemicals from the glands of ants

“…The structure of (2, E)-a-farnesene was recently confirmed by total ~y n t h e s i s . ~~ On the basis of their mass spectra, structures (43) and (44) have been proposed by Morgan and Wadhams '' for the homofarnesene and bishomofarnesene isolated from the Dufour gland of Myrmica ants.…”

Use of pheromone mimic to cause the disintegration and collapse of colonies of tent caterpillars (Malacosoma spp.)

“…Although sex pheromones and, to a lesser extent, alarm pheromones have been employed for many years in pest management programmes, trail pheromones have found little practical use. Apart from attempts to control ants by adding volatile trail pheromones to baits to enhance their attractiveness (Robinson et al. 1982; Vilela and Howse 1988; Greenberg and Klotz 2000), there have been no previous reports of successful attempts to manipulate pest populations by exploiting a dependency on trail‐based communication systems.…”