Description of the larval stages of Gymnochthebius jensenhaarupi and phylogenetic analysis of the relationships with other species of the subfamily Ochthebiinae (Coleoptera: Hydraenidae)

Abstract

Abstract. The three larval instars of Gymnochthebius jensenhaarupi (Knisch, 1924) are described and illustrated, including a detailed analysis of their chaetotaxy and porotaxy. The specimens used in this study were collected with adults of G. jensenhaarupi and have been identified as such by association. Comparative notes on the morphology of these larvae with other species of the subfamily Ochthebiinae are given. A hypothesis of phylogenetic relationships between G. jensenhaarupi and other members of Ochthebiinae with thoroughly described larvae is presented. The monophyly of Ochthebiinae is supported by additional larval features. On the other hand Ochthebius, as currently composed, seems to by paraphyletic. Gymnochthebius Orchymont, 1943 is confirmed as the sister group of Aulacochthebius Kuwert, 1887.

Larval morphology of the water beetleOchthebius balfourbrownei(Coleoptera: Hydraenidae) from marine rockpools of Cape Verde Islands

“…In conclusion, the results of our study provide additional support to the phylogenetic relationship between O. balfourbrownei and the species belonging to Calobius and Ochthebius. Likewise, this study highlighted the close relationships of O. balfourbrownei and O. subinteger, as confirmed usingthe molecular analyses of Sabatelli et al (2016) and Villastrigo et al (2019Villastrigo et al ( , 2020, with which it shares numerous characters, particularly the loss of temporal setae T2, considered at present an autapomorphic character for the genus Cobalius by Delgado and Soler (1996) and Delgado and Archangelsky (2005).…”

“…Herein, we excluded the larva of O. lejolisii from the comparison, because it was not described with modern and comparable criteria (D'Orchymont 1913). In comparison to the only larva of the Cobalius group to date studied according to modern criteria, O. subinteger (Delgado & Soler 1996), the larvae of O. balfourbrownei show numerous shared characters: presence of campaniform sensillum (FC1); presence of egg-bursters (EB), here extremely reduced; absence of temporal seta T2, a character that so far, as suggested by Delgado and Soler (1996) and Delgado and Archangelsky (2005), could constitute an autapomorphy for Cobalius; absence of campaniform sensillum (LC1) on lateral regions; absence of V2 on ventral regions; absence of tibiotarsal setae Ad1; presence of setae DP1 and DP2 on dorsopleural sclerites; sternite I without setae P1 and P3; absence of additional seta (D2) and pygopod without anal hooks (AH). However, the larvae of O. balfourbrownei may be distinguished from larvae of O. subinteger by the subapical, mesodorsal presence on antennomere II of one campaniform sensillum (IIC1), which seems to be an autapomorphic character of this species; Ligula (Lg) well developed, composed by two globose lobes; presence on mandibles of one conspicuous, triangular premolar tooth, slightly curved towards base; penicillus extremely reduced; molar area with two rows, one dorsal and one ventral, of small, denticulate microsculpture, basally directed; second labial palpomer with very small seta, medially directed; pronotum with one additional small seta posterior to A1 (A); mesonotal campaniform sensilla C1 and C2 absent and sternite I with one discal seta (D1).…”

“…In this paper, the general terminology of larval structures follows Lawrence (1991), while the chaetotaxy standards follow Delgado and Soler (1996, 1997a, 1997b, 1997c, Delgado and Archangelsky (2005) and Deler-Hernandez and .…”

Molecular ecology and phylogenetics of the water beetle genus Ochthebius revealed multiple independent shifts to marine rockpools lifestyle

“…However, a previous subdivision of Ochthebius into nine subgenera (Knisch ) is still followed by some authors ( e.g . Delgado & Archangelsky ). One relevant difference between the two classifications is that Cobalius Rey 1886, which following Knisch's () classification was considered as a valid subgenus, is now included in the nominal subgenus Ochthebius s.str.…”

Immature stages and biology of the enigmatic oxyporine rove beetles, with new data on Oxyporus larvae from the Russian Far East (Coleoptera: Staphylinidae)

“…Further exploration of the origin and functions of the pls, as well as establishing homology between various sensilla of Oxyporus and Atheta coriaria would lead to a better understanding of the evolution of these elements across Staphylinidae and increase their value as characters for phylogenetic reconstructions. A uniform chaeto taxy system for Staphylinidae comparable with systems used in other beetle families such as Carabidae (MAKAROV 2002, 2008), Hydrophilidae (FIKÁČEK et al 2008 or Hydraenidae (DELGADO et al 2005) could shed light on the sister group relationships of Oxyporinae and similarly controversial lineages within the family. Also, it could integrate larval characters of staphylinids into the framework of the entire beetle order.…”