The genus Alaolacon Candèze, a senior synonym of the genus Eumoeus Candèze (Coleoptera, Elateridae, Agrypninae)

Abstract Alaolacon Candèze, 1865 is found to be a senior synonym of Eumoeus Candèze, 1874, Luzonicus Fleutiaux, 1916 and Tharopsides Fleutiaux, 1918. Alaolacon is represented by Alaolacon bakeri (Fleutiaux, 1916), comb. n., Alaolacon candezei Fleutiaux, 1928, Alaolacon cyanipennis Candèze, 1865, Alaolacon fujiokai sp. n., Alaolacon griseus Candèze, 1874, Alaolacon megalopus sp. n., Alaolacon murrayi (Candèze, 1874), comb. n., and Alaolacon philippinensis nom. n. This genus is redescribed based on the descriptions of three species, Alaolacon candezei, Alaolacon fujiokai, and Alaolacon megalopus as well as the examination of the holotypes of Alaolacon cyanipennis and Alaolacon murrayi comb. n. Males of the genus Alaolacon exhibit 12-segmented and biflabellate antennae, and the females exhibit 11-segmented and subpectinate antennae. A key to species is provided.


Methods
Photographs of specimens were taken by a single-lens reflex camera (Canon EOS 70D) with a macro lens (Canon macro photo lens MP-E 65mm), and then images taken in a series of focal planes were combined using CombineZM 1.0.0 software (Alan Hadley, United Kingdom). Micrographs were prepared using a scanning electron microscope (SEM: Hitachi S-3000N) without gold coating.
Most structures were observed under a stereo microscope (Olympus-SZX9). Measurements are in millimeters and were made with a micro ruler (MR-2, Kenis Limited, Ôsaka; minimum scale value: 0.05 mm). Specimens were softened in warm water. The pregenital segments and genitalia extracted from the abdomen were soaked in 10% KOH solution (room temperature, male: 2 hours, female: 48 hours). The parts were cleaned in 30% ethanol (10 min) and dehydrated in 99.5% ethanol (5 min) and then mounted in glycerin on microscope slides, except the female genitalia, which were examined in water and then mounted in glycerin. A transmission microscope (Nikon Y-IDT) with a camera lucida was used to examine slides and for drawing. Morphological terminology follows Calder (1996), and Casari-Chen (1993) and Costa et al. (2010) in part. Photographs and drawings were edited with image editing software (Adobe Photoshop 7.0).
The following abbreviations are used: BL body length from head to elytral apices BW the maximum body width MIE the minimum distance between the eyes MAE the maximum distance across the eyes OI Ocular index: MIE/MAE × 100 PL the maximum pronotum length including posterior angles PML length of the midline of pronotum PW the maximum pronotum width including posterior angles PI  (Figs 1, 17, 20, 38, 55) 11-24 mm; surface smooth, with or without metallic luster on elytra; interspaces between punctures greater than puncture diameter except for narrower interspaces on head and pronotum. Vestiture. Setae flat, wider at midlength than base, with longitudinal micro carinae (Fig. 36); carinae converge at apex, apices acute or transverse (Fig. 37). Male. Antennomeres III-XII with setae filiform ventrally.
Abdomen. Male. Terigite VIII shorter than wide (Fig. 30) or longer than wide (Fig. 49 Diagnosis. Body black, elytra blue and with metallic luster, legs red-black; setae white; frontal depression moderate; eye small; female antennomere III subpectinate, 1.2 × as long as wide; prothorax almost as long as wide, widest posteriorly; pronotum with anterior angles bisinuate, median longitudinal depression shallow, not reaching anterior margin or base, punctate; anterior angles of hypomeron rounded; prosternal spine inclined weakly behind procoxae; scutellum concave laterally, widest near posterior 2/5; hind wings without wedge cell, with cross vein between veins MP4 and CuA2 located at contact point between veins MP3 and MP4; female sternite VIII with apex concave. Measurements Redescription of female. Body (Figs 1, 2) shiny; elytra with weak metallic luster. Color. Body black; mouth-parts brown, mandible black, galea and lacinia orange; elytra black-blue; pronotosternal sutures and legs red-black; tarsal claws yellow-brown. Hairs. Body covered with white flatted setae; antennomere I and legs with intermixed brown and white setae; antennomeres II-XI with brown setae. (Most setae of elytra lost.) Head. Frontal depression moderate (Fig. 4). Eyes small. Antennomere II conical; antennomere III longest, subpectinate, 1.2 × as long as wide, 3.0 × times as long as II; apical half part of antennomere XI thinner than its basal half part ( Fig. 5: dotted line). Apical maxillary palpomere 1.6 × as long as wide (Fig. 6).
Prothorax almost as long as wide, widest posteriorly; hind angles straight posteriorly. Pronotum with anterior angle bisinuate; median longitudinal depression shallow, not reaching anterior margin or base, punctate. Hypomeron with anterior angles rounded (Fig. 8). Prosternal spine inclined weakly (at 8 degrees) behind procoxae (Fig. 7). Scutellum (Fig. 10) 1.2 × as long as wide, concave laterally, widest near posterior 2/5. Hind wings with cross vein between veins MP4 and CuA2 apparent, not completely connected with CuA2, located at contact point between veins MP3 and Abdomen. Ventrite V 0.59 × as long as wide. Tergite VIII (Fig. 12) truncate apically. Sternite VIII (Fig. 13) widest at apical 1/3, apex concave; spiculum ventrale1.4 × longer than sternite VIII. Genitalia (Fig. 14). Ovipositor with coxites not sclerotized at apex (Fig. 15). Bursa copulatrix with three short sacs ( Fig. 16: arrows); without sclerotized structures.  This species are known only from the female holotype. We predict that the males also exhibit blue elytra and with metallic luster, scutellum widest near posterior 2/5, hind wings without wedge cell and with cross vein between veins MP4 and CuA2 located at contact point between veins MP3 and MP4. Janson and then to BMNH. Candèze's first collection of Elateridae (up to 1869) went to the BMNH, while a second collection of Elateridae went to IRSNB (Bousquet, 2016). BMNH can be most expected to hold types of this species because it was described before 1869. Label data of the examined specimen in BMNH agree with the original description. The external features of the specimen also agree with the original description. Thus, the specimen should be considered a syntype. Casari-Chen (1993) considered the type specimen as a homeotype. We designated the known syntype as lectotype to stabilize the classification.

Alaolacon cyanipennis
We could not locate other syntypes including at IRSNB in this time. Laporte de Castelnau's first collection was given to the National Institution of the Promotion of Science in Washington DC but was probably destroyed by fire, while part of his later collection was left to the Melbourne Museum in Australia (Bousquet 2016).
Only female specimens are known (Candèze 1865;Suzuki 2004). Only this species exhibits hind wings with wedge cell in this genus, whereas the other species lost wedge cell of hind wings. We predict that the male could also be recognized by presence of the wedge cell. Diagnosis. Body black, elytra blue and with metallic luster, legs black; setae black on dorsal side and white on ventral side; frontal depression deep; eye small; prothorax almost as long as wide, widest posteriorly; pronotum with anterior angles bisinuate and rounded, medina longitudinal depression deep, extending from before pronotal anterior margin to base, punctate; prosternal process inclined strongly behind procoxae; anterior angles of hypomeron acute; scutellum concave laterally, widest near posterior 1/3; hind wings with cross vein between veins MP4 and CuA2 located anterad to contact point between veins MP3 and MP4, without wedge cell; median lobe of male aedeagus stout.
Description of male. Body (Figs 20, 21) shiny, elytra with metallic luster. Color. Black except for elytra black-blue; mouth-parts brown-black, but mandible black, galea and lacinia orange; apical edge of tarsal segment V and tarsal claws red-brown; pregenital segments and aedeagus black-brown. Hairs. Dorsal surface covered with black flatted setae; ventral surface with white flatted setae; legs with intermixed black and white setae; mouth-parts and pronotal anterior margin near eyes with yellowbrown setae; filiform setae of antennomeres III-XII brown and long.
Remarks. This species is distinct by black body, blue elytra with metallic luster, black setae on dorsal side, white setae on ventral side and strong antennomeres III-XI flabellation. It is similar to Alaolacon candezei Fleutiaux, 1928 in having a black body, blue elytra with metallic luster, pronotum anterior angles bisinuate and rounded, and  Alaolacon fujiokai and A. candezei are similar species from the same island, but we recognized they are different species by the setal color and the hind wing venation. We believe that setal complementary color difference probably is not caused by sexual dimorphism because such dimorphism has not previously been observed in species of the Agrypninae. We also believe that differences in hind wing venation are unlikely to be caused by sexual dimorphism because such dimorphism has not previously been observed in species with flying females.
Only this species exhibits parallel sides of scutellum in this genus. The scutellum shape could be a useful specific diagnostic feature for this species including its female.  (Fig. 58). Diagnosis. Body red-brown, without metallic luster; setae yellow-brown; frontal depression deep; eye large; prothorax shorter than wide, widest posteriorly; pronotum with anterior angles bisinuate, median longitudinal depression not reaching anterior margin or base and impunctate at posterior half; anterior angles of hypomeron acute; prosternal spine inclined strongly behind procoxae; scutellum 1.3 × as long as wide, with sides straight, widest posteriorly; hind wings without cross vein between veins MP4 and CuA2 and wedge cell; male tergite VIII shorter than wide; median lobe of male aedeagus elongate.
Measurements Eumoeus and Tharopsides were described from males exhibiting 12-segmented and biflabellate antennae, whereas Luzonicus were described from female exhibiting 11-segmented and filiform to subpectinate antennae. Fleutiaux (1947) inferred that there was an occurrence of sexually dimorphic antennae of these genera, and that Luzonicus was therefore the senior synonym for Eumoeus and Tharopsides. Actually Eumoeus is the senior synonym for both Luzonicus and Tharopsides because the actions of Fleutiaux (1940) are nullified.
Alaolacon Candèze, 1865 was only known from female with 11-segmented and pectinate antennae. We determined that a male specimen (the holotype of A. fujiokai sp. n.), in possessing biflabellate antennae, belongs to Alaolacon because of the similarity to Alaolacon cyanipennis and Alaolacon candezei including: black body, blue elytra with metallic luster, pronotum anterior angles bisinuate, scutellum concave laterally. This association demonstrates that Alaolacon also has sexually dimorphic antennae.
In the tribe Hemirhipini, only four genera, Alaolacon, Eumoeus, Mocquerysia Fleutiaux, 1899 and Eleuphemus Hyslop, 1921 have strongly sexually dimorphic antennae. Their males exhibit 12-segmented and biflabellate antenna, and females exhibit 11-segmented and subpectinate antennae. Eleuphemus is separated from Alaolacon, Eumoeus, Mocquerysia (the latter three genera in parentheses) by the supra-antennal carinae continuous across frons (supra-antennal carina not continuous across frons) and mandible without subapical tooth (mandible with subapical tooth). Mocquerysia is separated from Alaolacon and Eumoeus (the latter two genera in parentheses), prosternal suture shortly grooved (prosternal suture not grooved), scutellum narrowed apically and with straight side (scutellum widest apically and concave laterally or with parallel sides in A. megalopus sp. n.), elytral intervals flat (elytral intervals convex). Candèze (1874) suggested that Alaolacon should be combined with Eumoeus if its male had biflabellate antennae. We recognized that Alaolacon and Eumoeus are similar by many structures: setae flat, wider at midlength than base, with longitudinal micro carinae (Figs 36,37); interspaces greater than puncture diameter except for smaller on head and pronotum; hypomeron mesal edge carinate anterolaterad (Figs 8,26,45: arrow); hind wings with vein r4 translucent (Figs 11,18,29,48). The two genera could not be separated from each other except by antennal morphology. This non-antennal similarity suggests that the two genera should be considered synonyms because antennal morphology is dimorphic in several other Elateridae. We propose that the two genera should be considered synonyms. Accordingly, the priorities of the generic names are following: Tharopsides < Luzonicus < Eumoeus < Alaolacon.
Luzonicus bakeri Fleutiaux, 1916 andT. bakeri Fleutiaux, 1918 are eventual homonyms since Luzonicus and Tharopsides are junior synonyms of Alaolacon. We propose A. philippinensis nom. n., as the replacement name for A. bakeri (Fleutiaux, 1916) comb. n. Alaolacon currently contains eight species, 1, A. bakeri, 2, A. candezei, 3, A. cyanipennis, 4, A. fujiokai, 5, A. griseus Candèze, 1874, 6, A. megalopus, 7, A. murrayi and 8, A. philippinensis. We could not find the types of two species, A. bakeri and A. philippinensis, and have not examined these species. Further effort to find the localities of the types of the two species are needed in order to understand the complete picture of these species.