Effect of asymmetric competition on distance among <i>Myrmeleon brasiliensis</i> (Návas, 1914) (Neuroptera: Myrmeleontidae) larvae

Abstract

In cases of asymmetric competition, larger individuals of many animal species have a greater probability of acquiring territory, gaining initial access to resources and finding a mate in comparison to smaller individuals. The competition among larvae of the antlion Myrmeleon brasiliensis (Neuroptera, Myrmeleontidae) is observed in the search for space for the construction of traps, in the forage for prey, and in the occurrence of cannibalism. The body size of the larvae is proportional to the size of the traps and the success of predation. Thus, larger specimens are better competitors in terms of capturing preys (asymmetric competition). The aim of the present study was to determine the effects of asymmetric competition in M. brasiliensis regarding the distance among these larvae. The study was developed in a permanent reserve area, located in the municipality of Aquidauana, from the Mato Grosso do Sul state, Brazil. For the laboratory experiments, we collected M. brasiliensis larvae and placed two larvae in plastic pots. The observations occurred by the visual search of traps, when a larva was seen in the diameter of its trap and the trap of its closest neighbor. Next, the trap size and the distance between them were measured for a period of 15 days. The results of the present study demonstrate that the largest M. brasiliensis larvae were outside the clusters. Within these clusters, the larvae moved away from each other because of the size of their traps, as the larger the neighboring larvae the greater the distance between them. Thus, the asymmetric competition between M. brasiliensis (larger larvae are better competitors) suggests a spatial arrangement among the larvae that is guided by the variable size of the trap.

Trap rebuilding by Myrmeleon brasiliensis larvae (Neuroptera: Myrmeleontidae) in response to flooding: the effect of body size

“…In the study conducted by Lima et al (2019), larger larvae were found more distant from the clusters in which the oviposition of the adult females occurred, suggesting that larvae of a certain size perform movements with greater frequency. According to Lucas (1985) and Fisher (1989), larger larvae are found more distant from their clusters in response to temperature, as larger antlion larvae are less capable of supporting warmer locations.…”

Distribuição Livre Ideal da formiga-leão (Insecta, Neuroptera)

“…Dentro dos agrupamentos, as larvas de formiga-leão maiores tendem a apresentar um maior sucesso na captura de presas, sendo assim as larvas menores deveriam deslocar-se em busca de áreas longe da interferência das larvas maiores. Entretanto, como as formigas, principal presa, evitam forragear nas áreas ocupadas por formigas-leão, as larvas maiores (por possuírem maior reserva energética e por suportarem a ação direta do sol) é que tendem a deslocar-se para fora dos agrupamentos (GOTELLI, 1996;MILER et al, 2018;LIMA et al, 2019). Sendo assim, as manchas com maior oferta de recurso DOI: https://doi.org/10.12741/2675-9276.v2.e014 estariam ocupadas pelas larvas maiores.…”