Interação planta-inseto: Aspectos biológicos e ecológicos do mutualismo Cecropia-Azteca

Abstract

EntomoBrasilis 8 (2): 85-90 (2015) FórumResumo. Uma associação bem conhecida dentre as interações ecológicas é o mutualismo entre plantas do gênero Cecropia e formigas, na maioria das vezes pertencentes ao gênero Azteca. Nesta interação, as formigas nidificam nas domáceas presentes no tronco oco das mirmecófitas e se alimentam de recursos alimentares fornecidos pela planta, conhecidos como corpúsculos mullerianos. Em compensação, as formigas protegem a planta hospedeira contra o ataque de herbívoros e a invasão por trepadeiras, e nutrem-na através de resíduos abandonados no tronco. Entretanto, a efetividade desta associação pode variar em função de vários fatores, como por exemplo, a espécie de formiga associada e o tipo de habitat da planta mirmecófita. Cerca de 10% das espécies de Cecropia perderam suas características atrativas, como por exemplo, espécies que habitam ilhas e altas altitudes. Aspectos como a riqueza de formigas associadas e estudos moleculares evidenciam que a colonização destas plantas ocorreu diversas vezes e independentemente por alguns gêneros de formigas. A pressão de seleção exercida por algumas espécies de formigas pode ter sido um dos fatores decisivos para o desenvolvimento dos traços atrativos para as formigas em Cecropia. Com a evolução destas características as formigas puderam se tornar um parceiro efetivo da planta, facilitando a co-evolução de interações mais específicas. Palavras-chave:Associação; Benefícios; Co-evolução; Formigas; Mirmecófita. Plant-Insect Interactions: Biological and Ecological Aspects of Cecropia-Azteca MutualismAbstract. A well-known association is the mutualism between plants is between plant species of the genus Cecropia and ants, mostly belonging to the genus Azteca. In this association, the ants nest in domatia present in the hollow trunk of this myrmecophytes and feed on food bodies provided by the plant, known as mullerian bodies. In return, the ants protect the host plant against herbivore attacks and invasion by vines, and nourish it through waste laid in the trunk. However, the effectiveness of this association may vary with several factors, such as the associated ant species and the habitat type of the myrmecophyte. About 10% of Cecropia species lost their attractive characteristics, such as species living in high altitude and inhabit islands. Aspects like associated ant richness and molecular studies show that the colonization of these plants by ants occurred several times and independently by different genera. The selection pressure exerted by some species of ants may have been one of the decisive factors for the development of attractive traits for ants in Cecropia. With the evolution of these features ants might become an effective partner of the plant, facilitating the co-evolution of specific interactions.

Natural history notes on worker size, colony size, and nest structure of Azteca muelleri Emery, 1893 (Hymenoptera: Formicidae) in Cecropia glaziovii (Rosales: Urticaceae) from the Atlantic Forest

“…Natural history studies (e.g., about ants) play a vital role in our understanding of biodiversity, evolution, and developing conservation programs (Rosumeck 2017) and they may help answer questions related to ants polymorphism; nest structure; influence of habitat on nest occupation; intranidal population and other invertebrates (other ants and non-ant arthropods) and nesting strategies (Longino 1991a). However, natural history works remain poorly explored due to the large effort required to conduct detailed descriptive studies, as in the case of ants occupying natural tree cavities (Oliveira et al 2015a;Morais & Benson 1988).…”

“…are colonized by Azteca Forel, 1878 ants by making a hole in the thinnest part of the inner wall of the trunk to nest (Longino 1991a). These natural cavities consist of small holes which open into the inside of stems or branches of the tree, and are divided by septa into a series of chambers also known as internodes (Longino 1991a;Oliveira et al 2015a). In these mutualistic interactions, Azteca ants protect vegetative and reproductive Cecropia organs (Oliveira et al 2015a(Oliveira et al , 2015b while plants provide shelter and food, such as Müllerian bodies (Vieira et al 2010).…”

“…These natural cavities consist of small holes which open into the inside of stems or branches of the tree, and are divided by septa into a series of chambers also known as internodes (Longino 1991a;Oliveira et al 2015a). In these mutualistic interactions, Azteca ants protect vegetative and reproductive Cecropia organs (Oliveira et al 2015a(Oliveira et al , 2015b while plants provide shelter and food, such as Müllerian bodies (Vieira et al 2010). This relationship is very successful and effective due to the high level of aggressivity of Azteca, which responds directly to leaf herbivory damage (Marting et al 2018a) and is one of the most studied interactions in Neotropics (Oliveira et al 2015a(Oliveira et al , 2015b.…”

“…On the literature just a few studies address A. muelleri biology and morphology (Longino, 1991a;Rocha & Bergallo 1992;Oliveira et al 2015aOliveira et al , 2015b and little is known about the biological characteristics of the nests of A. muelleri in Atlantic Forests fragments. In order to fill this gap, we describe some aspects of the natural history of A. muelleri related to (a) intranidal population, (b) nesting structure in C. glaziovii trees, and (c) worker and queen morphometrics.…”

“…The colony size of A. muelleri found nesting in C. glaziovii in fragments of Atlantic rainforest was similar to the colony size of other Azteca species, such as A. chartifex Forel, 1896 and A. alfari Emery, 1893 also nesting in Cecropia in fragments of Amazon rainforest (Vasconcelos & Casimiro 1997). Azteca's colony size may also depend on the species of Cecropia (Vasconcelos & Casimiro 1997) and size and age of the tree (Davidson & Fisher 1991), since nests are restricted by space inside trunks (Oliveira et al 2015a). The spatial distribution of A. muelleri ants along the cavities in the trunk of C. glaziovii was similar to other Azteca species (see Longino 1989).…”