Aesalus zhejiangensis Huang & Bi

Huang, Hao, Bi, Wen-Xuan & Li, Li-Zhen, 2009, Discovery of a second species of Aesalini from continental China, with description of the new species and its third instar larva (Coleoptera: Scarabaeoidea: Lucanidae), Zootaxa 2069, pp. 18-42 : 20-34

Aesalus zhejiangensis Huang & Bi , sp. nov.

( Figs. 1–56 , 62–86 )

Type material. Holotype ( Figs. 1–3 ): CHINA: Zhejiang Prov.: 3, Longquan City, Mt. Fengyangshan, 1600–1700m, pupa collected in the field on 31.VII.2008 by Wen-Xuan Bi and emerged in the laboratory 11 days later in VIII. 2008 ( SHEM, collection number 24215038). Paratypes: CHINA: Zhejiang Prov.: 113, 3ƤƤ, same data as for the holotype, mostly collected as adults and pupae in 31.VII–2.VIII.2008 by Wen- Xuan BI, pupae emerged in the laboratory 9–12 days later in VIII. 2008 (13 in SHEM, collection number 24215039, 1Ƥ in SHEM, collection number 24215040, 13 in BMNH, 13 in CHH, 13 in CCCQ, 53, 2ƤƤ in CBWX, 23 preserved in 100% ethanol in CHH).

Other material. CHINA: Zhejiang Prov.: 3 larval specimens, third (final) instar, Longquan City, Mt. Fengyangshan, 1600–1700m, collected in 31.VII–2.VIII.2008 by Wen-Xuan BI, preserved in 70% ethanol ( SHEM, collection number 24215041–24215043).

Holotype description. Measurement. PEL: 5.02, BT: 2.20, HL: 1.01, HW: 1.45, CHW: 1.45, ML: 0.36, PL: 1.50, PW: 2.45, EL: 4.02, EW: 2.95, PTL: 0.96, PTW: 0.35, MTL: 1.08, HTL: 1.20, BT/PEL: 0.44, EW/ PEL: 0.59.

Body oval, rather thick, elliptical in dorsal view and semicircular in lateral view with dorsal surface strongly convex; both dorsal and ventral surfaces dark blackish brown in color; dorsal surface shallowly punctate and covered with scattered, erect, stick-like bristles but without clumps of erect, scale-like bristles.

Head ( Fig. 4 ) nearly pentagonal, with anterior margin obtusely projected in the middle, clypeus not defined posteriorly; dorsal surface broadly punctate and irregularly covered with scattered, bristly setae. Eye appearing much wider on ventral surface than on dorsal surface; canthus ( Fig. 4 ) distinct, reaching lateral tip of eye and completely covering anterior half of margin. Mandibles bent at right angle on outer margin, with a broad base, a sharp apical tooth and a smaller, dorsal, subapical tooth. Mandibles with a few setae mainly on dorsal surface; without mola and prostheca but inner edge with short brushy area near base. Labrum (Fig. 24) free, transverse, expanding anteriorly and narrowed at base; approximately one fifth as wide as head and generally concealed by anterior margin of head; with brushy setae near anterior margin. Maxilla (Fig. 23) with well-developed palpifer (armature) and stipes; a small cardo; a brush-like galea and a small, narrow lacinia, which is free at apex. Maxillary palpus with 4 palpomeres (not counting palpifer), with terminal palpomere 4x as long as wide, spindle-shaped. Labium (Fig. 26) consisting of a simple ligula and separated palpus on anterior portion of dorsal surface of mentum; ligula plate shaped, not bilobed, with brushy setae anteriorly; palpal insertions separated by a distance equal to the width of basal palpifer; labial palpus with 3 palpomeres (not counting basal palpifer), with terminal palpomere 1.8 times as long as wide, somewhat spindle-shaped, and attached laterally. Mentum approximately 0.56 mm wide, more or less trapezoidal, with both anterior and posterior margins concave, with lateral margins convex; all marginal areas ridged and central area flat; surface punctate, with long curved setae mainly near margins; some punctures connected forming irregular sulcus. Submentum shallowly punctate and sparsely setose, not clearly separated from gula; gula smooth, glabrous. Antenna with 10 antennomeres, sparsely clad with long setae, weakly geniculate between scape and antennomere 2; scape a little curved; antennomere 2 subconical and nearly as long as wide; antennomere 3 elongated, approximately twice as long as wide; antennomeres 4 and 5 transverse; antennomeres 6 and 7 very short and acutely produced bilaterally; club formed by antennomeres 8-10, completely pubescent, weakly lamellate in shape, with antennomeres 8 and 9 transverse but antennomere 10 apparently longer.

Pronotum transverse, evenly convex dorsally, widest near posterior margin; surface punctate and almost evenly covered with scattered erect stick-like bristles but without clumps of erect scale-like bristles; punctures confused in distribution.

Scutellum ( Fig. 5 ) 0.26 mm long, nearly as long as wide, punctate.

Aesalus zhejiangensis , details. 14—apex of protibia in inner ventrolateral view to show inner spur and cavity; 15—protibia and protarsi of male in ventral view; 16—protibia and protarsi of male in dorsal view; 17—protibia and protarsi of female in dorsal view; 18—mesotibia and mesotarsi of male in ventral view; 19—mesotibia and mesotarsi of male in dorsal view; 20—mesotibia and mesotarsi of female in dorsal view; 21—metatibia and metatarsi of male in ventral view; 22—metatibia and metatarsi of female in ventral view; 23—left maxilla of male in ventral view; 24—labrum of male in dorsal view; 25—hindwing of male; 26—labium of male in dorsal view; 27—left mandible of female in dorsal view; 28—right mandible of female in dorsal view; 29—left mandible of female in mesal view; 30—right mandible of female in mesal view; 31—right mandible of female in ventral view; 32—left mandible of female in ventral view. Scales bars none for 14, 0.4 mm for 15–22, 0.1 mm for 23, 0.2 mm for 24, 1 mm for 25, 0.1 mm for 26, and 0.2 mm for 27–32. Abbreviations: as, apical spine; is, inner spur; c, cavity; la, lacinia; g, galea; mp, maxillary palpus; lp, labial palpus; lg, ligula; m, mentum; at, apical tooth; st, subapical tooth; ie, inner edge of mandible.

Elytra evenly and densely punctate on dorsal surface, with the pits (punctures) circular or oval, sharply defined; elytral vestiture evenly clad with erect, stick-like bristles, not squamose and without clumps of erect, scale-like bristles; each elytron with 11 longitudinal rows of stick-like bristles between suture and lateral margin; each interval of every 2 neighboring rows of bristles spaced by two waved rows of non-bristled punctures bearing 1–3 minute setae; most of punctures ( Fig. 5 ) nearly as large as those on discal area of pronotum (whereas in Aesalus satoi they have a diameter twice as great as in punctures on discal area of pronotum). Stick-like bristles ( Fig. 7 ) approximately 0.06 mm long, equal in length, cylindrical in general shape, parallel-sided, undivided, erect, somewhat rounded at apex, with discrete longitudinal ribs on their surface; each bristle inserted anteriorly in the pit floor ( Fig. 6 ) and anteriorly followed by a triangular tubercle ( Fig. 6 ) out of pit (exactly as in Aesalus satoi ). Each non-bristled puncture bearing 1–3 very minute, soft setae ( Fig. 6 ) anteriorly in pit floor. Under microscope, pits (punctures) shallow, circular or oval, with sharply defined margins, almost vertical walls, and a raised, flat-topped floor, and with floor and walls polygonally sculptured ( Fig. 8 ); pit floor rather flat, nearly in same plane of integument adjacent to pits; integument adjacent to the pits rather flat, not sculptured, but densely clad with very minute pores ( Fig. 8 ) that are even in size and confused in distribution. Ventral surface of elytra finely reticulate and sparsely clad with spinules and more sparsely with pits under microscope. Elytral epipleuron narrow, almost obsolete posteriorly, sinuate opposite the anterior edge of metacoxa.

Hindwing (Fig. 25) 8 mm long; venation as in Aesalus imanishii and Aesalus sichuanensis , with Holloway's (1969) veins 2dA1 and 2dA2 distinct but not reaching wing margin, and with vein 3dA1 present but not fully developed.

Intercoxal process of prosternum convex dorsally, expanding anteriorly, with all margins ridged; anterior margin straight but posterior margin rounded; surface punctate and clad with stick-like bristles. Metasternum without a pair of large cavities; finely punctate with all punctures bearing bristles; projected anteriorly with anterior margin straight and nearly reaching intercoxal process of prosternum; posterior portion with shallow sulcus for receiving hind leg. Mesocoxae separated by anterior projection of metasternum. Abdomen with five visible abdominal ventrites; first projected anteriorly, forming an intercoxal process of hind legs, somewhat triangular in shape, and fused with second ventrite in middle whereas other ventrites free; all ventrites with elongate foveae bearing minute setae; second to fifth ventrites all with small U-shaped depressions along anterior margins; first to fourth ventrites with crenulate posterior margin.

Profemur with ventral surface densely punctate and clad with setae. Protibia (Figs. 15–16) expanding from base to middle, then somewhat even in width throughout towards tip; outer lateral margin with 3 clear spines from the middle to apex, apical one being the longest; distal end of protibia with a cavity on ventral surface and inner lateral corner from which the protarsi arising; inner lateral corner of protibia (Fig. 14) with a spur on dorsal surface but without spur on ventral surface (such an inner spur corresponding to Howden & Lawrence's (1974) "subapical spine" for Lucanobium ), distal margin between inner spur and outer spine with a few denticles; ventral surface scotched irregularly, with two longitudinal ridges along which some yellow setae appearing; dorsal surface relatively smooth, with two curved longitudinal ridges but without any setae; both inner and outer lateral margins with soft setae. Protarsi clad with soft setae.

Mesotibia (Figs. 18–19) with two inner distal spurs, a very short spur on ventral surface and a longer spur on dorsal surface; outer lateral margin with 1 apical spine and 2 distinct spines near distal third, followed by a few minute spines towards base; both inner and outer lateral margins clad with setae; dorsal surface smooth and glabrous; ventral surface with 3 ridges bearing setae.

Metatibia (Figs. 21) with two inner distal spurs, a shorter one on ventral surface and a longer one on dorsal surface; apex projected outwards; outer lateral margin with a clear spine and 2 minute spines near middle; both inner and outer lateral margins clad with setae; dorsal surface smooth and glabrous; ventral surface with 3 ridges bearing setae.

Male genitalia ( Figs. 37–51 ) well sclerotized, yellowish brown, with very short basal piece fused to both parameres and penis (median lobe). Penis nearly cylindrical, with a weakly-sclerotized portion near distal end, with ventral surface strongly convex in middle and followed by a constricted part; distal part asymmetrical. Paired struts absent. Parameres slender, approximately half as long as penis ( Figs. 46, 48, 49 ). Internal sac ( Figs. 40–43 ) well developed as large irregular globe with an apparent accessory bursa projected backwards at dorsal side of penis; the largest diameter of internal sac nearly as long as penis. Ninth abdominal segment ( Figs. 37–39 ) well sclerotized except central part of ventral plate (as in Aesalus satoi ).

Male paratypes. Measurement (53 including the smallest specimen examined). PEL: 4.52–5.05, BT: 2.15–2.23, HL: 0.96–1.03, HW: 1.37–1.45, CHW: 1.37–1.45, ML: 0.30–0.36, PL: 1.37–1.52, PW: 2.28–2.48, EL: 3.75–4.02, EW: 2.74–2.95, PTL: 0.90–0.98, PTW: 0.30–0.36, MTL: 0.97–1.08, HTL: 1.10–1.20, BT/ PEL: 0.43–0.47, EW/PEL: 0.57–0.59.

Variation. Anterior margin of head more or less concave between the center and canthus, sometimes straight; canthus always reaching the lateral tip of eye, sometimes extending a little out of tip of eye; stick-like bristles appearing irregularly on dorsal surface of head, usually absent on canthus but sometimes present; scutellum slightly variable in the ratio of length/width, usually bullet-headed in shape but sometimes rather square; intercoxal process of prosternum slightly variable in width of central part, with posterior margin rounded or slightly pointed in middle; denticles on outer lateral margin of inner half of protibia variable in number and size; outer lateral margin of metatibia usually with two spines, sometimes only with 1 spine and 2 small denticles.

Female paratypes. Sexual dimorphism in external morphology. No constant difference in size and standard ratios of most body parts between male and female; no difference in length of canthus and anterior margin of head which are slightly marked in Aesalus satoi according to Araya & Yoshitomi (2003); no constant difference in center of anterior margin of head between male and female, the illustrated male paratype bearing a gap that is not found in other males and due to a damage; no difference in shape of mandible (Figs. 27–32). The only known constant difference is found in projection of outer distal end of metatibia, which is slightly broader in female (Fig. 22) than in male (Fig. 21).

Last abdominal ventrite ( Fig. 36 ) with a central projection on anterior margin, which is absent in male ( Fig. 35 ).

Hindwing as in male, with no difference in size, shape, and venation.

Female genitalia ( Figs. 52–56 , for a better understanding of some new terms used here, see "Comparative morphology and classification" and Fig. 87 ). Hemisternites well sclerotized and setose near rounded apex, with styli elongated, sclerotized, non-setose, hawk-beak-like and pointed outwards; bursal duct rather long and moderately narrow; intersection part swollen as the largest bursa, which probably is bursa copulatrix; inner wall of entrance to this bursa copulatrix strongly sclerotized as a loop with a pair of wings expanding the end of bursal duct; spermathecal duct rather slender and long, arising in the middle part of bursa copulatrix, widely separated from the base of the median oviduct; spermatheca rather small; spermathecal gland long and slender, not strongly demarcated from its duct; the combined length of spermathecal gland and its duct much greater than the length of the spermatheca; basal spermathecal part not swollen; basal bursal part contracted as a duct and very long; terminal bursal part swollen as a large bursa, which probably is accessory gland.

Biological notes ( Figs. 57–60 ). All the specimens including adults, pre-pupae, pupae, and larvae were collected from some decayed logs ( Fig. 57 ) that were in a forest dominated by broad-leaf trees including oak trees at approximately 1600–1700 m in altitude between 31 July and 2 August 2008. Some logs were inhabited only by larvae ( Fig. 59 ) whilst others had a few adults ( Fig. 60 ), pre-pupae, pupae, and larvae. The logs belong to a broad-leaf tree, but the species has not been identified. All adults were found in pupal cells ( Fig. 60 ) and were not active, apparently in dormancy stage. Most pupae emerged into adults after 9–12 days in laboratory. The stage from pre-pupa to adult lasted approximately 13–14 days in laboratory where the temperature was higher than in the field. All the logs inhabited by Aesalus were shaded in rather dark forest areas near a stream, and had a diameter of approximately 20–25 cm. The logs ( Fig. 58 ) had surface dark greyish brown without bark, usually smooth, and had some portion decayed as brown-rot but others as whiterot; the Aesalus were only found in the brown-rotten portion which was rather hard and wet, and were restricted to the dorsal or lateral part of logs, not found in the ventral side. In these logs some small ants and termites were found; in one of the logs some larvae of a Prostomis Latreille species (Tenebrionoidea: Prostomidae ) were also found.

The larval habitat of the new species is very similar to that of Aesalus satoi , but a little different from that of Aesalus sichuanensis . According to Imura & Araya's (2006) report and illustration, the logs inhabited by Aesalus sichuanensis were brown-rotten as in other Aesalus but the inner portion of logs was rather soft, not as hard as in Aesalus zhejiangensis .

Diagnosis. This new species is similar to Aesalus satoi in most external features, but can be distinguished from the latter by the following combination of characters: both sexes with canthus intruding farther into eye and reaching the lateral tip of eye; punctures on central area of head smaller; punctures on discal area of elytra with diameter 1/2–2/3 times as great as that of Aesalus satoi ; penis wider in ventral or dorsal view, with ventral surface much more convex and the distal non-sclerotized portion shorter and more constricted in lateral view; internal sac much larger than in Aesalus satoi ; styli of female genitalia apparently longer.

In distribution ( Fig. 61 ), this new species is very close to the first known species of Aesalus in continental China, Aesalus sichuanensis , but can be easily distinguished from the latter and a similar species, Aesalus imanishii from Taiwan, by having body relatively thicker, dorsal surface without clumps of erect scale-like bristles, canthus present and well developed, antenna consisting of 10 antennomeres, third antennomere elongated, intercoxal process of prosternum with anterior margin straight, sexual dimorphism of metatibia indistinct, parameres shorter, internal sac much larger, and hemisternites of female genitalia slenderer.

At a first look this new species is somewhat similar to the New World Aesalus neotropicalis Bates , but can be easily distinguished by having better developed canthus, more expanded prosternal process, shorter bristles, and rather flat surface around pits on vestiture.

Further diagnosis between the new species and other Aesalini species can be found in the key.

Type locality. China, Zhejiang Province, Longquan City, Mt. Fengyangshan.

Etymology. The specific name is derived from Zhejiang Province where the type locality is located.

Larval morphology ( Figs. 62–86 ). The most significant works on lucanid larvae were published by Emden (1935, 1951) and a review was given by Lawrence (1981). In Lawrence's paper, the most important larval characters for differentiation in Lucanidae were clarified, the relationships among the major groups and especially the more primitive genera were discussed, and a key was given to the primitive genera and a few of the more well-defined tribes of advanced Lucaninae. The most recent work relevant to larval lucanids was a phylogenetic analysis of Scarabaeoidea inferred from larval morphology by Grebennikov & Scholtz (2004). In this paper, up to 78 larval characters were employed for the analysis of phylogenetic relationships among families and subfamilies in Scarabaeoidea, and 14 species of Lucanidae were examined. Most of the characters used by Grebennikov & Scholtz are rather uniform throughout Lucanidae but varied among different families. In the following discussion, all the characters used by these authors have been examined in the new species.

Concerning the larval morphology of Aesalini, in Lawrence's (1981) review only the mandibular characters and sound producing organ on the middle and hind legs (pars strides and plectrum) were considered for Aesalus scarabaeoides , and in Grebennikov & Scholtz (2004) only Aesalus ulanowskii was examined, but some of the characters used by Lawrence were omitted. The larval morphology of all the other species of Aesalini has not been described in detail and only a few photos of larvae were published for Aesalus asiaticus , Aesalus imanishii , and Aesalus satoi . Araya & Yoshitomi (2003) mentioned that the third instar larva of Aesalus satoi "is quite similar in general appearance to those of the species of the subgenus Echinoaesalus , particularly having the same structure of anal sclerite consisting of three well-developed lobes," but their further study has not been published yet. As will be discussed in this paper, our current knowledge on phylogeny and systematics of Aesalini is very problematical and it will be very important to include all the larval morphological characters into a phylogenetic analysis.

For nearly all the characters used by Grebennikov & Scholtz (2004) in their higher phylogenetic analysis, Aesalus zhejiangensis has the same character states as in Aesalus ulanowskii except for the following: cranium ( Fig. 77 ) almost symmetrical; frontoclypeal suture ( Fig. 77 ) present and detectable along entire length between dorsal mandibular articulation; left apical antennomere with small apical sclerotized appendage but right apical antennomere without such appendage.

For the characters used by Lawrence (1981), a detailed description of third instar larva of Aesalus zhejiangensis is given below.

Antenna ( Figs. 67 , 72, 76 ). Antenna with 3 antennomeres excluding antennifer (referring to Lawrence's basal segment), with 4 antennomeres including antennifer, with the antennifer clearly marked, not fused to basal antennomere (referring to Lawrence's segment two). Basal antennomere longer than other antennomeres, not subdivided, bearing very few sensory spots but no seta. Penultimate antennomere (second antennomere, referring to Lawrence's segment three) bearing a few sensory spots mostly in anterior portion but no seta, with only 1 larger, rounded, cone-frustum-like and rather flat sensorium just below ultimate antennomere (apical or third antennomere). Ultimate antennomere about one third as long as penultimate antennomere. Left ultimate antennomere ( Fig. 76 ) bearing an apical appendage and 3 setae whereas right ultimate antennomere ( Fig. 72 ) bearing 2 setae but no apical appendage (in all 3 larval specimens examined).

Epipharynx ( Fig. 75 ). Phoba divided into an anterior section (namely protophoba) and lateral sections (namely chaetoparia). Protophoba distinct and consisting of many short, blunt and densely arranged pegs, which are greater in number than those of Syndesus cornutus (Fabricius) , and with about 9–10 sensory spots mostly in anterior portion, which are absent in Syndesus cornutus . Haptomerum well separated from protophoba, consisting of 4 sensory spots, but without setae or spine. Setae in chaetoparia nearly as many as pegs in protophoba. Haptolachus consisting of 3 nesia, the median one being more elongate and bearing very small granules, the lateral nesia bearing brushes of setae with the left one much smaller than the right one; all nesia without setae. Epitorma well sclerotized and sharp at tip. Pternotorma well developed and sharp at tip.

Mandibles ( Figs. 81–86 ). The term, "incisor teeth" used by Lawrence (1981) is somewhat misleading as incisor teeth sometimes can be explained as apical teeth; thus the term "inner teeth" will be used in this paper referring to Lawrence's incisor teeth. Left mandible with 3 apical teeth at tip, 2 penetrating molae at basal half, a ventral process at base and several inner tubercles along the inner edge between apical teeth and molae; apical teeth with dorsal one shorter and ventral one longer; inner tubercles minute and paler in color, not forming clear teeth; distal mola much longer and wider, with a concave, broad and somewhat vertical distal edge; basal mola shorter and smaller, somewhat triangular; ventral process rather big and paler. Right mandible with 2 apical teeth at tip, 2 simple molae at base and several inner tubercles between apical teeth and molae; apical teeth with dorsal one shorter than ventral one; inner tubercles greater in number than those of left mandible; both basal and distal molae restricted to dorsal side, triangular and rather shorter; ventral process fully developed as in left mandible. Outer edge of both mandibles coarse and dentate, with very few setae.

Mouthparts ( Figs. 79, 80 ). Stipes without stridulatory teeth. Galea and lacinia separate and fixed to stipes. Galea without membranous subdivision. Lacinia bidentate at apex, not tridentate. Maxillary palpus with 3 palpomeres excluding palpifer and with palpifer present. Prementum with straight anterior edge between insertions of palpi. Labial palpus with 2 palpomeres, rather straight and glabrous, without palpifer. Hypopharynx markedly asymmetrical with right dorsally pointed sclerotized projection.

Prothorax ( Fig. 78 ). Pronotum without an anteriorly projecting lobe or an extensive pronotal plate. Precoxale and episternum well sclerotized.

Mesocoxal stridulatory organ (pars stridens, Figs. 70, 73 ). Pars stridens on posterior surface of mesocoxa being of Lawrence's type one: field of confused, rounded granules, all about equal in size.

Metatrochanteral stridulatory organ (plectrum, Figs. 71, 74 ). Plectrum on anterior surface of metatrochanter consisting of at least 16 tight rows of granules; neighboring rows being spaced by a distance equal to the width of row; neighboring granules in the same row touched one another; granules oblong and a little rounded, smaller in terminal rows than in central rows.

Tarsungulus. Tarsungulus of prothoracic leg ( Fig. 69 ) 2x longer and more gradually attenuated at apex than that of mesothoracic ( Fig. 70 ) and metathoracic legs ( Fig. 71 ), flanked by 2 shorter setae arising from the same position on each side. Tarsungulus of mesothoracic and metathoracic legs strongly and abruptly attenuated at apex, forming a short median tooth, flanked by 2 longer setae arising from the same position on each side.

Vestiture of thoracic and abdominal tergites ( Figs. 62, 64 ). Spinules absent from prothoracic and mesothoracic tergites, very few on metathoracic tergite, fully developed on abdominal tergites 1–7, and absent from abdominal tergites 8–10.

Vestiture of abdominal sternite 10 ( Fig. 66 ). Raster absent. Only a transversal row of sparse and long setae appeared near posterior margin.

Anal sclerite. Anal sclerite ( Fig. 65 ) consisting of 3 lobes surrounding the anal opening and set off from the remainder of segment 10: a dorsal lobe and two lateral lobes. Abdominal sternite 10 about 1.5 times as long as tergite 10, causing anal sclerite somewhat oblique: dorsal lobe a little shorter than lateral lobes. All 3 lobes glabrous, with apparent oval pad.

After the study of the larvae of Aesalus zhejiangensis , we have some doubts about the Emden (1935, 1951) and Lawrence (1981) works concerning the presence of several inner tubercles on left mandible. In their works the number of inner teeth on the left mandible was used as a major character in larval classification, and a major split is based on the presence of at least one tooth along the inner edge of the left mandible between the two or three apical teeth and the mola, with the larvae possessing such inner teeth belonging to the subfamily Lucaninae ( sensu Holloway 1968 ) whilst the group lacking inner teeth includes Aesalus , Sinodendron , Ceruchus , Nicagus , Syndesus , Ceratognathus , and the subfamily Lampriminae . However, Aesalus zhejiangensis shows several small inner tubercles between apical teeth and mola, which cannot be easily distinguished from the inner teeth found in those Lucaninae species, such as Dorcus parallelipedus (Linnaeus) . Therefore we believe that the presence or absence of inner teeth cannot be used as a major character in classification of larval Lucanidae . Anyway, for a better larval classification more species need to be examined.

Figures

FIGURE 61. Distribution of Aesalini species in China and its surrounding areas. Abbreviations: U, Aesalus ulanowskii; SC, Aesalus scarabaeoides; S, Aesalus saburoi; H, Aesalus himalayicus; ST, Aesalus satoi; SI, Aesalus sichuanensis; E, Echinoaesalus species; Z, Aesalus zhejiangensis; I, Aesalus imanishii; A, Aesalus asiaticus. Arrows point to distributional records outside the range of the map.

FIGURE 87. Diagrammatic female genitalia showing the homologous structures used to unite different types of female genitalia in Aesalinae. Abbreviations: mo, median oviduct; bd, bursal duct; s, spermatheca; sd, spermathecal duct; sg, spermathecal gland; ip (1), intersection part (part 1); bsp (2), basal spermathecal part (part 2); bbp (3), basal bursal part (part 3); tp (4), terminal bursal part (part 4).

FIGURES 1 – 8. Aesalus zhejiangensis, habitus and details. 1 — dorsal view, male holotype; 2 — ventral view, male holotype; 3 — lateral view, male holotype; 4 — head in dorsal view to show canthus, anterior margin, mandibles, labrum; 5 — vestiture of pronotum and elytra around scutellum to show comparative size of punctures; 6 — microstructure of elytra under stereoscope to show position and distribution of bristles, tubercles, and tomenta on vestiture; 7 — stick-like bristles; 8 — microstructure of elytra under 400 x microscope to show polygonally sculpturing of pit and pores. Scale bars 1 mm for 1 – 3, 0.4 mm for 4, 0.5 mm for 5, 0.2 mm for 6, 0.02 mm for 7 – 8. Abbreviations: m, male; f, female; tu, tubercles; b, bristles; t, tomenta; p, pores; ps, polygonally sculpturing.

FIGURES 9 – 13. Aesalus zhejiangensis, details. 9 — head in ventral view to show mentum, submentum, and canthus; 10 — intercoxal process of prosternum in left lateral view; 11 — intercoxal process of prosternum in ventral view; 12 — abdominal ventrites in ventral view; 13 — antenna. Scale bars 0.4 mm for 9, 0.2 mm for 10 – 11, 0.4 mm for 12, and 0.2 mm for 13.

FIGURES 33 – 51. Last abdominal tergite and ventrite and male genitalia of Aesalus zhejiangensis. 33 — last abdominal tergite of male in dorsal view; 34 — last abdominal tergite of female in dorsal view; 35 — last abdominal ventrite of male in ventral view; 36 — last abdominal ventrite of female in ventral view; 37 — ninth abdominal segment of male paratype one; 38 — ninth abdominal segment of male paratype two; 39 — ninth abdominal segment of male paratype three; 40 — penis and internal sac of male paratype one in dorsolateral view to show accessory bursa projected backwards; 41 — penis and internal sac of male paratype two in dorsolateral view; 42 — penis and internal sac of male paratype one in ventral view; 43 — penis and internal sac of male paratype one in lateral view; 44 — penis of male paratype three in right lateral view; 45 — penis of male paratype three in dorsolateral view; 46 — penis of male paratype three in dorsal view; 47 — penis of male paratype three in left lateral view; 48 — penis of male paratype three in ventrolateral view; 49 — penis of male paratype three in ventral view; 50 — penis of male paratype one in left lateral view; 51 — penis of male paratype two in left lateral view. Scale bars 0.4 mm for all. Abbreviation: TP, tip of paramere.

FIGURES 52 – 56. Female genitalia of Aesalus zhejiangensis. 52 — whole genitalia on dark background to show membranous structures; 53 — whole genitalia on bright background to show sclerotized structures; 54 — hemisternite and stylus; 55 — sclerotized entrance of bursa copulatrix in lateral view; 56 — sclerotized entrance of bursa copulatrix in dorsal view. Scale bars 0.4 mm for all. Abbreviations: HS, hemisternite; MO, median oviduct; BD, bursal duct; SE, sclerotized entrance of bursa copulatrix; BC, bursa copulatrix; SD, spermathecal duct; S, spermatheca; SG, spermathecal gland; DAG, duct of accessory gland; AG, accessory gland; ST, stylus.

FIGURES 62 – 67. Third instar larval habitus of Aesalus zhejiangensis before being disarticulated and cleaned. 62 — larva straightened in dorsal view; 63 — larva straightened in ventral view; 64 — larva slightly straightened in lateral view; 65 — tenth abdominal segment and anal sclerite in dorsal view to show tergite ten and the three lobes surrounding the anal opening; 66 — tenth abdominal segment and anal sclerite in ventral view to show sternite ten (raster absent) and two lateral lobes; 67 — head in anterior view. Scale bars 1 mm for 62 – 66, and none for 67.

FIGURES 68 – 76. Third instar larval morphology of Aesalus zhejiangensis. 68 — right legs in ventral view in natural shape; 69 — fore leg in anterior view; 70 — middle leg in posterior view; 71 — hind leg in anterior view; 72 — right antenna in lateral view; 73 — right mesocoxa in posterior view to show pars stridens; 74 — right metatrochanter in anterior view to show plectrum; 75 — epipharynx in ventral view; 76 — left antenna in lateral view. Scale bars none for 68, 0.2 mm for 69 – 73 and 75, 0.1 mm for 74 and 76. Abbreviations: ps, pars stridens; pl, plectrum; hm, haptomerum; pp, protophoba; c, chaetoparia; e, epitorma; pt, pternotorma; hl, haptolachus; n, nesium; sa, sclerotized antennifer; ba, basal antennomere; pa, penultimate antennomere; aa, apical antennomere; ss, sensory spot; sm, sensorium; a, apical sclerotized appendage.

FIGURES 77 – 86. Third instar larval morphology of Aesalus zhejiangensis. 77 — epipharynx, clypeus, and anterior portion of head; 78 — prothorax and fore leg in right lateral view; 79 — maxilla in mesal view to show the bidentate apex of lacinia; 80 — mouthpart in dorsal view; 81 — left mandible in dorsal view; 82 — left mandible in mesal view; 83 — left mandible in ventral view; 84 — right mandible in dorsal view; 85 — right mandible in mesal view; 86 — right mandible in ventral view. Scale bars 0.2 mm for 81 – 86. Abbreviations: ss, sensory spot; st, seta; ex, epipharynx; c, clypeus; fc, frontoclypeal suture; fs, frontal sutures; pc, precoxale; es, episternum; ba, bidentate apex of lacinia; mp, maxillary palpus; p, palpifer; s, stipes; g, galea; l, lacinia; hy, hypopharynx; ha, hypopharyngeal armature; at, apical tooth; m, mola; it, inner tubercle; vp, ventral mandibular process.

FIGURES 57 – 60. Field observations of Aesalus zhejiangensis. 57 — biotope; 58 — a partially brown, rotten log inhabited by Aesalus; 59 — third instar larva found in brown, rotten portion of log; 60 — newly emerged adult in pupal cell.