Hydrolutos breweri sp. n., a new aquatic Lutosini species (Orthoptera: Anostostomatidae) from Churí-tepui (Chimantá Massif, Venezuela)

Abstract

Hydrolutos breweri, a new species of Lutosini (Orthoptera: Anostostomatidae) from Cueva Charles Brewer (Churí-tepui, Guyana Highlands, Venezuela) is described and figured. Inhabiting aquatic environment it represents an unusual orthopteran with sternal and pleural area covered by fine microtrichia forming a plastron.

Patterns in Orthoptera biodiversity. I. Adaptations in ecological and evolutionary contexts

“…These species live in perpetual darkness associated with freshwater pools and streams flowing through the caverns. These insects are highly adapted to move easily, and even swim against strong currents in this semi-aquatic environment showing the same defensive behaviour previously described above, of staying underwater when disturbed (Šmida et al 2005;Derka & Fedor 2010). Despite being cavernicolous these species cannot be considered true troglobionts because they lack adaptations such as reduced eyes or lack of body pigmentation.…”

“…This group belongs to the Gondwanaland Anostostomatidae, the family that includes wetas and king crickets (Johns, 1997). The genus Hydrolutos Issa & Jaffe includes six species of apterous, troglophilic, medium-sized crickets which are found in quartzite caves of tepuis or tafelbergs of the Roraima Formation of Venezuela (Issa & Jaffe, 1999;Šmida et al 2005;Derka & Fedor, 2010;Derka et al 2013). These species live in perpetual darkness associated with freshwater pools and streams flowing through the caverns.…”

“…Despite being cavernicolous these species cannot be considered true troglobionts because they lack adaptations such as reduced eyes or lack of body pigmentation. For this reason, they are expected to inhabit streams outside caves on the tepui (Derka & Fedor 2010).…”

Minor Insect Orders

“…The most widespread aquatic species is Cornops aquaticum (Bruner, 1906) (Acrididae), which occurs from southern Mexico to central Argentina. Six species of the genus Hydrolutos (Anostostomatidae) are endemic to streams and marshes of tepui (table-top mountains) in Venezuela (Issa and Jaffe, 1999;Derka and Fedor, 2010;Derka et al, 2013). The first three nymphal instars consume water hyacinth exclusively, whereas nearly 80% of the diets of fourth and fifth instars and adults are hyacinth (Capello et al, 2011).…”

Parakari a New Genus of the Family Baetidae (Insecta: Ephemeroptera) from Guyana Highlands

“…It is true also for many aquatic species with an endemic geographical distribution (e.g. Čiampor & Kodada 1999, Issa & Jaffe 1999, Kodada & Jäch 1999, Derka 2002, DeMarmels 2007, Derka et al 2009, Derka & Fedor 2010. Tepuis are remains of a gigantic eroded surface that has been dissected by the Amazon and Orinoco basins.…”