Effects of ants (Hymenoptera: Formicidae) on flying insect visitor behaviour and fruit production in açaí palm (Euterpe oleracea Martius)

Abstract

Açaí palm (Euterpe oleracea) production in the Amazon region has grown rapidly in recent decades to meet both domestic and international demand for the fruit. Understanding functional roles of different insects in açaí fruit production is essential for the development of sustainable management practices and the conservation of associated biodiversity in plantations. Ants play a variety of key roles in agroecosystems, particularly as predators, but may also influence crop pollination, either directly (as legitimate pollinators) or indirectly by altering behaviour/density of other flower visitors. Here, we compare flower visitor communities, behavioural interactions between ants and flying insects and fruit production in açaí inflorescences, under the experimental exclusion of ants. Flying insects differed in their response to experimental exclusion of ants, with bees and flies found in higher abundance on inflorescences where ants had been excluded. In contrast, beetles and wasps were unaffected by ant exclosure. Among bees, only medium‐sized species, but not small‐sized and large‐sized species, were affected by the presence of ants. However, fruit production on inflorescences did not differ among ant exclosure treatments. We found clear evidence that ants interfere with flying insects visiting açaí inflorescences, but these changes do not affect açaí fruit production, likely due to the large diversity of flying insects that contribute to pollination services. Therefore, given their potential role as pest natural enemies, control of ant colonies in plantations is not recommended.

Synthesis of the current state of ant knowledge in the Brazilian Amazon: a review

“…Cortef et al (1999) and Scott et al (2006) highlighted characteristics that make certain groups of organisms ecologically effective for studies, including playing an important role in the ecosystem, having a wide distribution, being easy to sample, having a low financial cost, presenting a measurable response to environmental changes, able to reproduce in captivity, and easy to study in situ and in laboratories. In this sense, many groups of animals have been used as a basis for decision making, whether for the recovery of degraded areas or forms of sustainable use (EMER et al, 2013;SEMPRUC et al, 2015;CAJAIBA et al, 2017;BELÉM et al, 2020).…”