Larval morphology of Crephelochares and Peltochares (Coleoptera: Hydrophilidae) Author Minoshima, Yûsuke N. Natural History Division, Kitakyushu Museum of Natural History and Human History, Author Fikáček, Martin - & National Museum of the Czech Republic, Department of Entomology, Cirkusová 1740, CZ- 19300 Prague Author Liu, Hsing-Che - text Acta Entomologica Musei Nationalis Pragae 2023 Acta. Ent. Mus. Natl. Pragae 2023-11-24 63 2 305 322 http://dx.doi.org/10.37520/aemnp.2023.019 journal article 10.37520/aemnp.2023.019 1804-6487 334F2DE5-BB4C-4FF6-B345-FF9975CCB701 Identity of Peltochares larvae by BERTRAND (1962) BERTRAND (1962) described some hydrophilid larvae collected in Madagascar as belonging to the genus Peltochares , based on the identity of the associated adults, which resembled Peltochares conspicuus by their flat and disc-like body. However, P. conspicuus or similar species of Peltochares have never been recorded from Madagascar , and the identification is therefore doubtful (GIRṒN & Table 2. Summary of current knowledge of morphology of Acidocerinae larvae. See Table 3 for references.

Characters	Helochares group		Agraphydrus gr.	Chasmogenus gr.
	Helobata	Helochares	Novochares	Peltochares	Sindolus	Agraphydrus	Crephelochares
Frontal lines	lyriform	lyriform	lyriform	lyriform	lyriform	V-shaped	?
Coronal line	absent	very short / short	very short	short	very short	very short	very short
Nasale	without teeth	with teeth	with teeth	with teeth	with teeth	with teeth	serrated / with distinct teeth
Nasale	symmetrical	asymmetrical	asymmetrical	symmetrical	asymmetrical	asymmetrical	symmetrical / asymmetrical
gFR1 composed of	one row	one row	one row	one row	one row	one row	two rows
Epistomal lobes	symmetrical	asymmetrical	asymmetrical	almost symmetrical	asymmetrical	asymmetrical	symmetrical / asymmetrical
Shape of epistomal lobes	projecting and truncate	projecting	weakly projecting	rounded	rounded	weakly projecting	rounded / weakly projecting
Number of setae of gFR2	4	3–4	4	4	4	2–4	3
Long paddle-shaped seta on frontale	?	present	?	present	?	present	absent (shape of FR8 not known)
FR6	?	long, paddle-sha- ped	?	short, paddle- -shaped	?	long, trichoid	short, trichoid
FR9	?	long, trichoid	?	long, paddle- -shaped	?	long, paddle-sha- ped	short, trichoid
Long paddle-shaped seta on parietale	?	present	?	present	?	present	present
Position of PA7, 12, 13	?	forming a row, PA7 between PA12 and PA13	?	loosely forming trian- gular group	?	forming very closely aggregated triangular group	forming rather closely aggre- gated triangular group
PA8	?	trichoid	?	paddle-shaped	?	paddle-shaped /?trichoid	trichoid
PA11	?	distant from PA14	?	distant from PA14	?	close to PA14	close to PA14
Inner projection of antennomere 1	absent	absent	absent	present	absent	absent	absent
Mandibles	symmetrical	symmetrical	almost symmetrical	symmetrical	almost symmetrical	asymmetrical	asymmetrical
Distal inner tooth of right mandible	simple	simple	simple	simple	simple	bifurcate / simple	bifurcate
Dorsal sclerotization of maxillary palpo- mere 1	complete	incomplete	?complete	incomplete	?complete	incomplete	complete
MX5	trichoid	paddle-shaped	?trichoid	paddle-shaped	trichoid	paddle-shaped	paddle-shaped
Lateral face of mentum	not rounded	not rounded	not rounded	not rounded	not rounded	weakly rounded	rounded
Anterior corner of mentum	angulate	angulate	angulate	projected anteriorly	angulate	angulate	angulate
Cervical sclerites	not subdivi- ded	not subdivided	not subdivi- ded	not subdivi- ded	not subdivi- ded	not subdivided	subdivided
Abdominal prolegs	absent	absent	absent	absent	absent	present	present
Dorsal apex of abdo- minal segment 8	sinuate	sinuate	?	strongly projected, trilobate	?	sinuate / rounded	sinuate
Acrocercus	?absent	short	?	long	?	long / short	very long

SHORT 2021 ). The larvae of P. atropiceus described here do not correspond with those described by BERTRAND (1962) and we hence consider the identification of the Malagasy larvae to be incorrect. This fact raises the question of the identity of the larvae. Judging from the description and figures by BERTRAND (1962), we consider that the larvae belong to Tritonus Mulsant, 1844, of the tribe Laccobiini . This is supported by the following evidence: (1) Tritonus species are flat and disc-like in body shape and superficially similar to P. conspicuus ( SHORT 2008 , FIKÁĆEK et al. 2017 ). (2) Tritonus is distributed in Madagascar ( SHORT 2008 ). (3) The specimens in BERTRAND (1962) were collected on wet rock surfaces, which is the habitat of Tritonus in Madagascar ( SHORT 2008 , FIKÁĆEK et al. 2017 ). (4) Many characters of the larvae described by BERTRAND (1962) correspond with Tritonus larvae described by FIKÁĆEK et al. (2017) : the epistomal lobes are almost symmetrical; the nasale is slightly asymmetrical, with four teeth; the shape of the frontal and coronal lines is identical to that of Tritonus ; the mandibles are symmetrical and with three inner teeth; the pronotum is oval in shape; the metathorax has a pair of triangular dorsal plates; the legs are well-developed. BERTRAND (1962) only did not mention the elongated spiracles, which were described in FIKÁĆEK et al. (2017) . The larval and adult morphology, habitat and distributional data of the ‘ Peltochares ’ larvae described by BERTRAND (1962) indicate that these larvae most likely belong to the genus Tritonus .