Spatial and temporal fluctuations of the abundance of Neotropical cave-dwelling moth Hypena sp. (Noctuidae, Lepidoptera) influenced by temperature and humidity

Abstract

The present study evaluated the seasonal variation of a population of Hypena sp. in the Gruta Taboa (Sete Lagoas, Minas Gerais, Brazil), in relation to changes in temperature and humidity during the dry (July 1999 and July 2000) and rainy (January 2000 and January 2001) seasons. The Hypena sp. population responded to external seasonality, being distributed closer to the cave entrance during the rainy season, in which temperature and humidity fluctuated around 21 °C and 85%, respectively. During the dry season abundance was higher in sections farther from the entrance (deeper sections) (19.2 °C temperature and 80% humidity). The results showed that this species is influenced by external environmental factors, even in a tropical region where the external climate fluctuations are lower compared to temperate regions.

Step back! Niche dynamics in cave-dwelling predators

“…Although for certain epigean taxa the dynamic nature of the niche has been recognized (Nieder, 1997;Roy and Thomas, 2003;Willson et al, 2010), it has been rarely demonstrated in the case of subterranean ecosystems (Crouau- Roy et al, 1992;Rendo s et al, 2012;Tobin et al, 2013;Ferreira et al, 2015). The combination of different and novel statistical tools, proved to be a powerful analytical setting for the detection and the quantification of such dynamics, especially at the local scale.…”

An ecological survey of the invertebrate community at the epigean/hypogean interface

“…According to the results of the GAMM, the prevalence of external elements dropped significantly during winter. Seasonal dynamics in faunal assemblages were observed by previous authors focusing on MSS (e.g., Crouau-Roy et al 1992, Nitzu et al 2011, Rendoš et al 2012, 2016a) and on caves (e.g., Tobin et al 2013, Ferreira et al 2015, Mammola et al 2015, Bento et al 2016, Lunghi et al 2017. It is possible to argue that, over the year, at the blurry epigean/hypogean interface, there are complex exchanges involving fauna with different levels of subterranean adaptation (Prous et al 2004, Moseley 2009, Novak et al 2012, which introduce fundamental trophic resources in the subterranean habitat (Novak et al 2013) but also cause greater fluctuations in species composition over the year.…”

Trogloregions: delimiting subterranean faunistic identities in Afrotropics and Neotropics

“…Althuogh subterranean communities may be determined by regional and local processes as in any other external environment, these communities are generally very simpli ed due to the highly limiting conditions, and the relative environment stability, factors that end up reducing the genetic variability of the populations 11,15 . Environmental stability is a key point, as subterranean communities can be directly affected by environmental uctuations in both the external and subterranean environments 30,31,44 . Apparently, environmental stability is one of the main "attractors" for populations that may come and colonize these environments, ceasing the selection of characteristics that can be advantageous under the great unpredictability of the surface environment 15 .…”

“…Apparently, environmental stability is one of the main "attractors" for populations that may come and colonize these environments, ceasing the selection of characteristics that can be advantageous under the great unpredictability of the surface environment 15 . Considering the cave environment, organisms can, for example, adapt their distributions according to uctuations in temperature or relative humidity, which are much less pronounced than in the external environments 44,45 . Regarding the environmental stability in the external habitats, climatic oscillations on the surface can extinguish epigean populations, while hypogean populations can be spared, resulting in their isolation 30,31 .…”