Identification of a novel plant-derived attractant for Acromyrmex lobicornis leaf-cutting ants

Abstract

Leaf-cutting ants are considered major pests of agriculture and forestry in the Neotropics. Attractive toxic baits are the prevailing method for managing them. Thus, there is great interest in identifying attractants to incorporate into these baits. Moreover, leaf-cutting ants can avoid toxic baits by associating the attractant with the toxin. We evaluated attractiveness of heptyl butyrate, a volatile compound found in fresh apples and plums. We conducted field experiments with ten colonies of Acromyrmex lobicornis. First, we evaluated the behaviour of ants exposed to heptyl butyrate at 1% by surrounding resources. Then, we compared the attractiveness of heptyl butyrate and orange pulp, the most commonly used attractant. Finally, we evaluated whether heptyl butyrate increases the attractiveness of a carbohydrate resource at varying doses. Heptyl butyrate at 1% attracted 92% more ants than the control and that it was as attractive as orange pulp. Heptyl butyrate paired with sucrose at concentrations of 0.001 and 0.1% was more attractive than sucrose alone, but greater concentrations did not increase sucrose's attractiveness. Therefore, heptyl butyrate could be added to toxic baits to manage A. lobicornis as it is as attractive as the most commonly used attractant and can be applied directly to the pellets.

Damage reduction of Acromyrmex lobicornis in Pinus ponderosa using mixed pine species in combination with push–pull tools

“…Arena designs included mono‐specific ponderosa ( N = 8 treated, N = 5 control), mono‐specific contorta ( N = 10 treated, N = 5 control) or mixed pines design with one group of each species ( N = 10 treated) (Figure 1). For treated mono‐specific designs, one group of three trees functioned as the pull stimulus (i.e., attractant) by applying 10 g dehydrated citrus pulp around the base of the plants (Alma et al, 2019; Carlos et al, 2009), whereas the other group of trees served as the push stimulus (i.e., repellent), by spraying each tree with 10 mL of tea tree formulation at 10% (Buteler et al, 2021). For the mixed pine design, the contorta group received 10 g of dehydrated citrus pulp stimulus, and the ponderosa group received the tea tree push stimulus.…”

“…from young willows. Moreover, other studies have evaluated the use of plant‐based repellents (Buteler et al, 2021) and attractants (Alma et al, 2019) to divert LCA feeding, showing that they can be used as tools in a push–pull strategy.…”

Act locally, think globally: Ant studies in Argentina in the context of ecological theory

“…Another tool for management of pest ants is the use of repellent and attractant stimuli. Different plant-based compounds, plant species, and even waste generated by the ants themselves have been demonstrated to modulate ant foraging behavior (Farji-Brener and Sasal 2003;Ballari and Farji-Brener 2006;Medina et al 2012;Perri et al 2017;Alma et al 2019;Buteler et al 2021). Among those with repellent action, tea tree oil (a complex mixture of terpene hydrocarbons and tertiary alcohols distilled mainly from plantation stands of the Australian native plant Melaleuca alternifolia) and farnesol (present in many essential oils, such as Pluchea dioscoridis and Pittosporum undulatum) repel leaf-cutting ants at short distance in both laboratory and field assays (Perri et al 2017;Buteler et al 2021).…”

“…Even though its repellent effect is short-lived, further research identifying the compounds that cause the effect could lead to a novel ant repellent. In addition, heptyl butyrate, a volatile compound found in fresh apples and plums, and orange pulp can be used as attractant stimuli (Perri et al 2017;Alma et al 2019). Attractants and repellents could be combined in an IPM strategy termed push-pull, which involves the manipulation of ant foraging behavior by integrating stimuli that turns crops unsuitable or unattractive to the insect pest (push) and simultaneously attracts them towards another resource (pull) from where the pest is subsequently removed (Cook et al 2007).…”