Phylogenetic Relationships of the Tribe Vatellini Based on Larval Morphology, with Description of Derovatellus lentus (Coleoptera: Dytiscidae: Hydroporinae)

Abstract

ABSTRAGT The phylogenetic relationships and putative monophyly of the diving-beetle tdbe Vatellini are explored based on a cladistic analysis of 37 taxa and 122 chaetotaxic and morphological characters from larvae. For this purpose, larvae of the genus Derovatellus Sharp are descdbed and illustrated in detail, with particular emphasis on morphometry and chaetotaxy, with the later being unexplored until now. The results strongly support the monophyly of the Vatellini based on several unique larval characters. The terminal insertion of the primary seta UR8 on the second urogomphomere in members of Vatellini represents a reversal from the dedved condition. Vatellini was recovered as the sister group of the Australian genus Antiporus Sharp (Hydropodni) based on the presence of: a spatulate nasale, pore PAe and elongate lateral spinulae on prementum. These characters, however, have a reduced value because all of them seem to have evolved several times independently within the Hydroporinae. The tdbe Vatellini and its genera are diagnosed and compared with other hydropodne taxa, and interesting features are discussed. Vatellus Aube is unique within Hydropodnae in the presence of secondary setae on the first antennomere and the first maxillary palpomere, and the one-segmented labial palpus. Derovatellus can be separated from almost every other Hydropodnae by the absence of seta LAI on prementum and of secondary anterodorsal setae on femur.KEY WORDS diving beetles, larvae, phylogenetic relationships, chaetotaxyThe vatellines are a distinctive group among diving range compdsing the Afrotropical, Nearctic, Neotrobeetles in which the adults have evolved certain mor-pical, and Odental regions (Nilsson 2001 ). In the Neophological characters that make them unique (Miller tropics, Derovatellus includes six species, the most 2005). The larvae are considerably less known than common and widespread of which is D. hnttts adults, but not less interesting judging from certain (Wehncke),distdbuted from central Argentina to the morphological features such as the disproportionately Gadbbean (Miller 2005). long and cudous nasale and the extremely elongate The phylogenetic relationships and putative monoabdominal siphon (Michat and Torres 2005). Mem-phyly of the Vatellini were studied recently, considbers of this group are small, the adults range from =3.0 edng different sets of characters. Miller (2001) and to 7.5 mm in length and occur in ponds, marshes and Miller et al. (2006) based on adult characters, and slow streams with considerable emergent vegetation Ribera et al. (2008) based on molecular characters (Miller 2005). The larvae are found in the same hab-found evidence for the monophyly of the Vatellini.itats, but in general are much more difficult to locate With respect to the position of the tdbe within Hythan adults, and considerable sampling and sorting dropodnae, however, there is no general agreement effort is needed before collecting a significant number among studies using different data sets. Miller (2001 ) of specimens. ...

Higher‐level phylogeny of diving beetles (Coleoptera: Dytiscidae) based on larval characters

“…There is a general agreement in recognizing Vatellini as a natural group (e.g. Miller, , ; Michat & Torres, , ; Miller et al ., ; Ribera et al ., ). In our study, this tribe is recovered as monophyletic with strong support (Fig.…”

“…Natatory setae on the legs evolved several times independently within Dytiscidae: in the tribe Laccophilini; in the common ancestor of the large group including Matinae, Colymbetinae, Coptotominae, Lancetinae, Dytiscinae and Cybistrinae; and several times within the Hydroporinae. Contrary to earlier diverging lineages, biological data (Wilson, ; Galewski, ; Michat & Torres, , ) suggest that larvae of these taxa live in association with the aquatic vegetation, thus supporting several independent transitions into more vegetated microhabitats. As suggested by Galewski (), a correlation between presence of natatory setae and utilization of more vegetated microhabitats seems evident.…”

Phylogenetic relationships, larval morphology, and chaetotaxy of the subfamily Coptotominae (Coleoptera: Dytiscidae)

“…Both character states, however, must be seen as less meaningful evolutionarily because they are present in other dytiscid taxa. The primary setae LA10 and LA12 are well developed in the Hydroporinae except Vatellini (see Michat and Torres 2005, 2011) compared with very small to minute in the Colymbetinae, Copelatinae, Dytiscinae, and Lancetinae (Michat et al 2005; Alarie et al 2009, 2011; Michat and Torres 2009). On the other hand, the pore ABc is also absent in the hydroporine tribe Bidessini (Michat and Alarie 2008) and in the dytiscine tribes Aciliini and Eretini (Alarie et al 2011).…”