Effect of rain on trap building by Myrmeleon brasiliensis in a riparian woodland from the Cerrado biome in Brazil

Abstract

In areas of the Cerrado biome (Brazilian savanna) with well-defined rainy and dry seasons, changes in climate and landscape affect the abundance and seasonality of insects. Larvae of the antlion Myrmeleon brasiliensis (N avas) (Neuroptera: Myrmeleontidae) are predators that build traps in dry sandy soil to capture prey. Here we determined the effect of rain on trap building by M. brasiliensis larvae in a riparian forest in the Cerrado biome. Differences in population size and developmental stage were found between the rainy and dry seasons. In the laboratory, the effect of rain-soaked soil on trap building was evaluated. Fewer antlion larvae were found in the rainy season. Moreover, a greater abundance of larvae in the final stage of development (third instar) was found in the dry season, whereas more first instars were found in the rainy season. The latter revealed that wet soil affects the trap building of the larvae, as smaller traps were built in the treatment with soaked soil (simulated rain), whereas the larvae in the control treatment (no rain) continued building traps with no change in size. The findings indicate that seasonality in the Cerrado biome exerts a short-term influence on M. brasiliensis larvae (larvae build fewer traps) as well as a long-term influence (association with life cycle).

Sand-throwing behaviour in pit-building antlion larvae: insights from finite-element modelling

“…In general, pit-building antlions prefer fine over coarse sand (reviewed in [9]), dry over wet sand [62][63][64] and rather low sand densities over higher densities [36]. Here, the construction of a pitfall trap seems to represent an advanced predatory strategy [25,29,43,64,65].…”

Influence of the microhabitat on the trap construction of Myrmeleon brasiliensis (Neuroptera: Myrmeleontidae) larvae

“…In the area near the rocky cliff of the hill (protected environment), only larvae in the more peripheral portion of the area were affected by rainfall, whereas those closer to the sandstone cliff wall continued foraging throughout the year. Laboratory experiments have been demonstrated that M. brasiliensis larvae rebuild their smaller size traps after the rain, when the soil dries out again (within five days, on average) (Freire & Lima, 2019).…”

From individuals to populations: How homo‐ and heterospecific interactions influence habitat selection in a sit‐and‐wait predator

“…The particle size of the substrate influences larval behaviour, as does the shape of the trap, which may be deeper in fine sand due to greater stability of the trap wall and, therefore, more efficient at capturing prey (Botz et al, 2003; Büsse et al, 2021; Devetak et al, 2020; Griffiths, 1980, 1986; Klokočovnik et al, 2012; Klokočovnik & Devetak, 2022; Wilson, 1974). If traps are constructed in less suitable substrate, this can have long‐term consequences for phenology or may result in a slower larval life cycle (Freire & Lima, 2019; Gotelli, 1993; Miler et al, 2019; Morrison, 2004). All these factors should be considered when evaluating both predator–prey interactions and inter‐ and intraspecific interactions.…”

“…Different factors affects pit-building species. Substrate particle size and density (Barkae et al, 2010;Devetak et al, 2012;Devetak & Arnett, 2015), humidity (Freire & Lima, 2019;Fukada & Nisimura, 2021;Miler et al, 2019), temperature (Ábrahám, 2003;Antoł et al, 2018;Miler et al, 2020) and density of prey as well as conspecific and heterospecifics (Barkae et al, 2014(Barkae et al, , 2017Farji-Brener & Amador-Vargas, 2020;Griffiths, 1980;Griffiths, 1991;Polis, 1981) are probably some of the most important.…”