Which plant traits matter? Bromelia antiacantha Bertol. (Bromeliaceae) as a hibernation site for Brachystethus geniculatus (Fabricius) (Hemiptera, Pentatomidae, Edessinae)

Abstract

ABSTRACT Diapause is a process of decreased metabolic activity in insects. In latitudes with a well-defined cold season, diapause or hibernation is a strategy to survive in periods of resource scarcity. In Pentatomidae, this phenomenon is studied mainly in non-natural environments and with species of economic importance. This work aimed to determine which variables influence the abundance of Brachystethus geniculatus on its hibernation site, Bromelia antiacantha. Samplings were carried out monthly, from July to September of 2019, in a remnant of Atlantic Forest in southern Brazil. The height, diameter, cup height, leaf width, and abundance of bromeliads per plant cluster were evaluated for their correlation with the abundance of B. geniculatus in bromeliads. We collected 24 individuals for analysis of fat bodies, in order to check diapause. We found 70 individuals of B. geniculatus distributed in 33 of the 61 bromeliads examined. The number of B. geniculatus per bromeliad was positively correlated with the cup height, that influences the opening of the leaves and consequently decreases the exposure to environmental weathering, and the number of bromeliads per group, possibly because more leaves and spines around the cup may help avoid predation. Parasitism on B. geniculatus by tachinid flies was recorded in the field.