Eur. J. Entomol. 112(4): 831–843, 2015 doi: 10.14411/eje.2015.085 ISSN 1210-5759 (print), 1802-8829 (online) Phylogenetic relationships and larval morphology of the recently described diving beetle genus Laccomimus (Coleoptera: Dytiscidae: Laccophilinae) MARIANO C. MICHAT 1 and MARIO TOLEDO 2 1 IBBEA, CONICET-UBA, Laboratory of Entomology, DBBE-FCEN, University of Buenos Aires, Argentina; e-mail:
[email protected] 2 Museo di Storia Naturale, Università di Parma, via Farini 90, 43100 Parma, Italy; e-mail:
[email protected] Key words. Coleoptera, Dytiscidae, Laccophilini, Laccomimus, larva, morphometry, chaetotaxy, ground plan, phylogeny Abstract. The larvae of the diving beetle genus Laccomimus Toledo & Michat, 2015 (Laccophilinae) are studied for the first time, based on detailed descriptions and illustrations of all instars of L. distinctus Toledo & Michat, 2015, with particular emphasis on mor- phometry and chaetotaxy. The phylogenetic relationships of this genus within the tribe Laccophilini are analyzed cladistically. Lac- comimus is recovered as part of a clade that includes the genera Australphilus Watts, 1978, Neptosternus Sharp, 1882 and Laccophilus Leach, 1815 and is characterized by the presence of natatory setae on the tibia and tarsus, and within this clade it is a sister to the other genera. Third-instar larvae of Laccomimus and Africophilus Guignot, 1948 share the mediodistal insertion of the seta CO7 on the meso- and metacoxa, a short and spine-like seta TI6 on the metatibia, a ventrally sclerotized abdominal segment V and a short urogom- phus. These characters are considered plesiomorphic and indicate a basal position of both genera within the Laccophilini.