Larval ground plan of Platynectes Régimbart, 1879 reconsidered: description of the larvae of three species with phylogenetic considerations (Coleoptera: Adephaga, Dytiscidae).

In this contribution we describe and illustrate for the first time the larvae of three species of Platynectes Régimbart, 1879 (P. agallithoplotes Gustafson, Short & Miller, 2016, P. bakewelli (Clark, 1863), and P.

Morphology of the larvae of Rhantaticus congestus (Klug, 1833) and phylogenetic comparison with other known Aciliini (Coleoptera: Dytiscidae: Dytiscinae).

We describe the second- and third instar larvae of the diving beetle Rhantaticus congestus (Klug, 1833), including detailed morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, terminal abdominal segment and urogomphi in order to discover useful characters for distinguishing Rhantaticus Sharp, 1882 larvae from those of other known Aciliini (Coleoptera: Dytiscidae: Dytiscinae). A parsimony analysis based on 94 larval characteristics of nine Aciliini species in five genera (Acilius Leach, 1817, Graphoderus Dejean, 1833, Rhantaticus, Sandracottus Sharp, 1882, Thermonectus Dejean, 1833) was conducted using the program TNT. Rhantaticus shares with all these genera several larval character states which support its inclusion in the Aciliini.

Bunites distigma (Brull, 1837): discovery of the second- and third-instar larvae and phylogenetic relationships within the Colymbetinae (Coleoptera: Dytiscidae).

The second- and third-instar larvae of the diving beetle Bunites distigma (Brull, 1837) are described and illustrated for the first time, including detailed morphometric and chaetotaxic analyses of selected structures, and their phylogenetic relationships within the Colymbetinae are re-evaluated. The results support previous hypotheses on the position of this genus based on first-instar characters, as Bunites Spangler, 1972 shares a common origin with Meladema Laporte, 1835, Hoperius Fall, 1927 and Neoscutopterus J. Balfour-Browne, 1943, and within this clade, it is sister to Meladema.

The very rare Japanese endemic diving beetle Japanolaccophilus niponensis (Kamiya, 1939), (Coleoptera: Dytiscidae, Laccophilinae): larval morphology and phylogenetic comparison with other known Laccophilini.

The three larval instars of Japanolaccophilus niponensis (Kamiya, 1939) (Coleoptera: Adephaga, Laccophilinae) are described for the first time according to the now genevralized larval descriptive format of Dytiscidae (Coleoptera: Adephaga), which incorporates detailed chaetotaxic and morphometric analyses. A parsimony analysis based on larval characteristics of 14 Laccophilini species in seven genera was conducted using the program TNT. One of the main results is that Japanolaccophilus Satô, 1972, which so far was treated as being related to Neptosternus Sharp, 1882 now stands out as sister to Laccophilus Leach, 1815, and Philodytes J.