Interference of β-eudesmol in nestmate recognition inAtta sexdens rubropilosa(Hymenoptera: Formicidae)

Abstract

Leaf-cutter ant species (Atta spp.) are key pests of cultivated crops in the Neotropics, and recent studies have demonstrated that workers of Atta spp., particularly of Atta sexdens rubropilosa, exhibit aggressive behavior among nestmates when in contact with the sesquiterpene beta-eudesmol, found in leaves of Eucalyptus maculata. However, the underlying mechanism sparking this behavior pattern has yet to be investigated. This work aimed to elucidate the mechanism by which this substance elicits aggression in workers of A. sexdens rubropilosa. The results, thus obtained, showed that beta-eudesmol is able to modify the chemical composition of the workers cuticle, impairing nestmate recognition, triggering alarm behavior and leading to nestmate aggression.

Managing leaf-cutting ants: peculiarities, trends and challenges

“…Natural products have had and continue to have crop protection value both as per se insecticides or as chemical backbones for new insecticide molecules, but these products are still limited by the same concerns and shortcomings as synthetic compounds. Some natural compounds, particularly from plant extracts (unlike others, such as lime stone), show promise against leaf‐cutting ants in laboratory experiments, either affecting the ants themselves or their cultivated fungus . However, their potential for field use still deserves attention because, for example, high vapor pressure as in the β ‐eudesmol, a bioactive compound from an Eucalyptus clone effective against leaf‐cutting ants, precludes such use despite its potent interference with nestmate recognition; such interference leads to aggression and high mortality among nestmates (Fig.…”

“…However, their potential for field use still deserves attention because, for example, high vapor pressure as in the β ‐eudesmol, a bioactive compound from an Eucalyptus clone effective against leaf‐cutting ants, precludes such use despite its potent interference with nestmate recognition; such interference leads to aggression and high mortality among nestmates (Fig. ) …”

“…1). 129,131 Compounds that modulate behavior are also objects of attention against leaf-cutting ants, and, among these, natural repellents show promise. Some plants and plant extracts, as recently recognized in the Programme of Applied Research to Popular Medicine in the Caribbean (TRAMIL), initiated in 1982, do exhibit repellence to leaf-cutting ants and may prove useful in association with cultivated plants, thereby diversifying the crop system and minimizing the risk of attack.…”

An Overview of Integrated Management of Leaf-Cutting Ants (Hymenoptera: Formicidae) in Brazilian Forest Plantations

“…Insecticides, like β-eudesmol from eucalyptus leaves, may interfere with ant behaviour [71][72][73]. Sesquiterpene modified the chemical composition of the ant worker cuticles, confusing their recognition within the nest and triggering alarmed and aggressive behavior [73].…”

Potential use of essential oils to control the leaf-cutting ants; Atta sexdens rubropilosa and Acromyrmex subterraneus molestans (Hymenoptera: Formicidae)

“…Some of these substances can act directly against the ant, leading to its death, such as citrus seed oils; Citrus sinensis (L.) Osbeck, Citrus limon (L.) Burm or Citrus reticulate Blanco (Rutaceae) (Fernandes et al, 2002). Other Plants can be toxic to leaf-cutting ants, such as Tithonia diversifolia (Asteraceae), Ricinus communis (Euphorbiaceae), Eucalyptus maculate (Myrtaceae), Hymenaea courbaril (Fabaceae) (North et al, 2000;Marinho et al, 2005;Marinho et al, 2008;Alonso et al, 2013;Castaño-Quintana et al, 2013) and/or to their fungus, such as Piper piresii (Piperaceae), Simarouba versicolor (Simaroubaceae), Raulinoa echinata Coffea spp. (Rutaceae) (Biavatti et al, 2002;Pagnocca et al, 2006;Peñaflor et al, 2009) …”