Raractocetus kreusleri
Creators: name: Lawrence, John F.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Lymexylidae
Raractocetus
Raractocetus kreusleri

description: Raractocetus kreusleri (Pascoe, 1864)
(Figs 12, 17)
Atractocerus kreusleri Pascoe, 1864: 46. Type,
Diagnosis. This species is slenderer and much darker in colour than R. emarginatus and has a short median pronotal groove.
Redescription. Colour of head behind eyes and pronotum dark brown to black, elytra yellowish-brown, more or less unicoloured; exposed tergites reddish-brown; undersurfaces reddish-brown to dark brown; eyes and palporgan black. Vestiture of short, dense, yellow or pale hairs. Length: males 14–25 (1.89 – 2.8) mm (n = 15); females 16–35 (26.6 – 4.1) mm (n = 35). Body length/elytral width 9.95–13.90 (11.78). Head 1.61 times as long as wide, somewhat declined, gradually narrowed behind eyes, without temples or neck; base weakly biemarginate dorsally, surface evenly convex. Eye about as long as head width and as long as wide, strongly protruding with anterior edge emarginate, finely facetted but ocellate, with interfacetal setae slightly longer than width of an eye facet; distance between eyes dorsally 0.05 times distance across them in male and and 0.1 times in female; distance between eyes ventrally about 0.25 times distance across them in both sexes. Antennal insertions concealed by frontal ridges which extend into eye emargination. Clypeus 0.38 times as long as wide, with sides curved and converging to broadly emarginate apex. Labrum 0.6 times as wide as clypeus, 0.5 times as long as wide, with sides strongly curved, apex broadly rounded and disc densely setose with longest setae anteromesally. Antennae in male 1.6 times as long as head width, 11-segmented; ratio of antennomere lengths: 2.40: 1.90: 2.00: 1.60: 1.50: 1.30: 1.20:1.10: 1.10: 1.00: 4.00; antennomere length/width ratios: 1.26, 1.00, 1.18, 1.07, 1.15, 1.18, 1.33, 1.57, 1.83, 1.67, 6.67. Antennae in female 2.27 times as long as head width, 12-segmented; ratio of antennomere lengths 1.35, 1.00, 1.40, 1.30, 1.30, 1.25, 1.20, 1.05, 1.05, 1.00, 0.95; 1.00; antennomere length/width ratios: 1.42: 1.00: 1.22: 1.08: 1.13: 1.14: 1.20:1.10: 1.17: 1.43: 1.58, 3.33; terminal antennomere acute at apex. Mandible about 1.36 times as long as wide; outer edge gradually curved and densely setose; apex bidentate with dorsal lobe distinctly longer than ventral one; mola and prostheca absent. Maxilla with galea 2.33 times as long as wide, parallel-sided, broadly rounded apically; lacinia shorter than galea, 2.75 times as long as wide with narrowly rounded apex; maxillary palp in male with first palpomere half as long as wide and much shorter than others; second and third palpomeres obliquely connate forming a globular structure 1.2 times as long as wide, fourth long and slender with narrowly rounded apex; palp organ with about 13 major branches and numerous secondary ones; in female four palpomeres more or less similar to those in male and palp organ with about 8 major branches and numerous secondary ones. Mentum 0.5 times as long as wide, broadly rounded at base and subtruncate at apex; ligula membranous, slightly longer than labial palp and narrowly rounded apex. labial palps 2-segmented with large palpigers, separated by much less than basal width of one; basal palpomere 0.33 times as long as wide and apical palpomere more than 10 times as long as basal one, 2.5 times as long as wide, parallel-sided and flattened, with truncate apex. Submental peduncle strongly transverse, with truncate apex and paired, slightly diverging, narrowly rounded anterolateral lobes, not separated from gular region; gular sutures subparallel; gula slightly shorter than wide. Ventral surface of head slightly biconcave, with short subantennal grooves. Cervical sclerites 2.7 times as long as wide, slightly constricted at middle with posterior half wider than anterior half. Pronotum 1.06–1.20 (1.12) times as long as wide, barely wider at posterior fourth with sides more or less parallel, without lateral carinae; anterior edge strongly rounded; anterior angles absent, posterior angles more or less right; posterior edge weakly emarginate on either side of very short, broad, prescutellar lobe slightly concave at apex; disc moderately steeply sloped laterally and flattened mesally, with median longitudinal groove and endocarina just behind middle; punctation fine and dense, vestiture of inclined or suberect fine hairs. Prosternum about 0.6 times as long as mid length of a procoxal cavity, anteriorly deeply emarginate; surface relatively flat; notosternal sutures oblique. Prosternal process apparently short, broad and apically truncate (possibly absent, if apparent process represents floor of sternum). Procoxal cavities large and broadly open externally and internally, of an unusual shape, with anterior edge strongly oblique, with small anterolateral notch at base of notosternal suture; postcoxal process absent; protrochantin well-developed, externally visible, transverse, mesally slender and laterally subtriangular. Scutellum virtually absent, consisting of a short strip of cuticle weakly bilobed at apex, not separated from scutum, which has a complete median endocarina and is concave laterally to house sub-basal portions of elytra. Elytra 1.69–2.00 (1.81) times as long as greatest combined width and 1.63–2.00 (1.84) times as long as pronotum; separated for most of their lengths, but meeting at anterior sixth; each elytron about 3.5 times as long as wide, wid-est at anterior fifth, with outer edge straight and oblique anteriorly, interlocking with lateral scutal groove, weakly curved posteriorly, inner edge more or less sinuate and apex very broadly rounded; humeri and anterolateral angles absent; punctation fine, confused and bearing short, inclined hairs. Mesoventrite highly reduced, infolded and almost completely replaced by mesanepisterna, which meet at midline to form a single plate, except at posterior edge, where the two halves separate on either side of a small, remnant of the mesoventrite; anterior edge of plate broadly, deeply emarginate, without coxal rests; sides steeply declined to meet mesepimera; surface smooth and apunctate mesally but densely punctate and setose on steep lateral sections; posterior remnant of mesoventrite and its discrimen extending posteriorly for a short distance and acute at apex. Mesocoxal cavities very weakly impressed, contiguous, with obliquely angulate anterior edges and without posterior edges, partly closed laterally by mesepimera. Metaventrite 1.20 times as long at midline and 1.60 times as long laterally as greatest width, strongly convex, without discrimen; posterior edge strongly oblique and sinuate on either side of subacute intercoxal lobe. Metanepisternum about 6.27 times as long as wide, widest anteriorly with sides slightly curved and strongly converging to narrowly truncate apex. Metendosternite with long, narrow stalk, paired, slender lateral arms forming an angle of about 30° and a long, slender, apically acute anterior process and no laminae or anterior tendons. Hind wing about 2.85 times long as wide; apical field 0.29 times total wing length, without radial extensions; radial cell absent; radial and medial veins joined at apical third of wing by transverse connection, straight anteriorly, sinuate posteriorly and probably derived from cross-vein r4 and the radiomedial loop; MP 1+2 long, straight and continuing as medial spur to wing margin; medial field with four veins (CuA 1+2, CuA 3+4, CuP + AA 3 and AA 4), all extending to wing margin. Anal lobe moderately well-developed, without embayment, containing AP 3+4. Procoxa 3.00 times as long as wide, widest near base and very slightly narrowed to apex, strongly projecting; Mesocoxa 2.50 times as long as wide, widest near base and slightly narrowed apically, slightly projecting. Metacoxa 0.0.3 times as long as wide, strongly oblique, almost contiguous and projecting near midline, without coxal cowling on mesal half. Trochanterofemoral joints strongly oblique, but with femur well separated from coxa. Fore legs relatively short: profemur 2.4 times as long as wide; protibia 1.25 times as long as femur, 5 times as long as wide, slightly expanded at apex; protarsi combined 1.2 times as long as tibia, with segment length ratio 2.25: 1.75: 2.25: 1.00: 2.75. Mid and hind legs longer and slenderer. Mesofemur 3.5 times as long as wide, slightly wider at middle; mesotibia 1.57 times as long as femur, 11 times as long as wide and more or less parallel-sided; combined tarsal length 1.53 times that of tibia, with segment lengths 2.23: 1.61: 1.38: 1.00: 1.54. Metafemur 3.67 times as long as wide, slightly wider at middle; metatibia 1.59 times as long as femur, 11.7 times as long as wide and more or less parallel-sided; combined tarsal length 1.56 times that of tibia, with segment lengths 2.13: 1.53: 1.33: 1.00: 1.27. Pretarsal claws moderately long and slender, empodium with multisetose. Abdomen with most tergites and sternites subequal in length and degree of sclerotisation; male with 7 ventrites (sternites II–VIII) and female with 6 (II–VII); first ventrite in both sexes somewhat shorter than second, without intercoxal process; ventrites 2–5 (sternites III–VI) and their corresponding tergites more or less equal in length, the sternites with narrow, poorly defined laterosternites and spiracles located in pleural membrane. Ventrite 6 (sternite VII) in male 1.18 times as long as 5 with broadly curved apex; tergite VII 1.9 times as long as wide and truncate at apex; sternite VIII in male half as long as VII, 1.56 times as long as wide, with sides subparallel to apical fourth and shortly, abruptly converging to form apical lobe, which is gradually narrowed to subacute apex; tergite VIII of similar size and shape but with apical lobe subtruncate. Segment IX with pregenital ring moderately wide at base but subacute at apex (anteriorly); sternite 1.9 times as long as wide, divided into an anterior triangular section, lying within the pregenital ring, and a shorter, parallel-sided posterior section, which is deeply emarginate apically to form a pair of apically rounded lobes; tergite IX subquadrate, evenly sclerotised and fused to segment X, which is 1.5 times as long as IX, 0.7 times as long as wide at base, with sides slightly narrowed to basal third and parallel-sided to subtruncate apex. Aedeagus with basale 1.34 times as long as wide, widest at posterior edge and gradually narrowing to rounded base; apicale 0.78 times as long as basale, divided into paired parameroids, each of which is 2.22 times as long as wide with outer edge sightly curved, inner edge bearing a large, apically widened, heavily sclerotised lobe and bearing at base a pair of tegminal struts, one attached to the opposite strut and to the penis and the other joined only to the opposite strut. Penis 1.2 times as long as basale and 4.2 times as long as wide, curved, with apex narrow and slightly cleft and with pair of broad basal struts about 0.6 times as long as body of penis. Ventrite 6 (sternite VII) in female 1.27 times as long as 5, 2.38 times as long as wide, parallel-sided, with broadly rounded apex, tergite VII slightly shorter with subtruncate apex; segment VIII in female about half as long as VII, twice as a long as wide and widest at middle, with sides curved and both tergites and sternites membranous along midline; spiculum ventrale 1.67 times as long as segment and articulated at base. Oviposi-tor 10.5 times as long as wide, more or less parallel-sided; paraprocts 1.75 times as long as gonocoxites, which are 3.45 times as long as wide; apical coxital lobe about 1.5 times as long as basal lobe, densely setose with subacute apex; gonostyli about 0.08 times as long as gonocoxite, 2.67 times as long as wide, parallel-sided and attached laterally; ventral sclerite 0.86 times as long as gonocoxite; proctiger narrowly rounded apically.
Specimens examined. ACT: Black Mountain, 21.ii.1956, light trap, I.F.B. Common (1♁, 1♀, ANIC); Black Mountain, 25.i.1955, light trap, I.F.B. Common (1♁, 13♀♀, ANIC); Canberra, 27.i.1982, at light, I. D. Naumann (1♀, ANIC); Canberra, 26.i.1958, W. J. M. Vestjens (1♀, ANIC); Canberra, 31.i.1961, E. F. Riek (1♀, ANIC); Dea-kin, 30.i.1977, E. B. Britton (2♀♀, ANIC); Lyneham, i–ii.1964, B. P. Moore (1♁, ANIC); Lyons, 19.i.2018, at light, C. R. Schipp (2♁♁, ANIC); Mt. Ainslie, 2.ii.1969, at light, E. M. Reed (2♀♀, ANIC); Mt. Ainslie, 22.i.1977, E. Reed (1♀, ANIC); Sydney, 5.xii.1906, W. W. Froggatt (1♀, ANIC). NSW: Batlow, 1 mi. NE, Sydney, 5.xii.1906, W. W. Froggatt (1♀, ANIC); Binnaway, 1.1934, H. C. Field (1♀, AMS); Bogan River, J. Armstrong (2♁♁, 1♀, ANIC); Gundaroo Rd., 11.i.1978, 22.i.1980, B. P. Moore (2♁♁, ANIC); Gunning, 29.i.1998 (1♁, 1♀, ANIC); Holbrook, 17 mi. NE, 2.ii.1956, I.F.B. Common (2♁♁, 1♀ ANIC); Houlaghan’s Creek, 10 mi. N Wagga Wagga, 20.i.1967, B. Cantrell (10♀♀, QMB); Marrar, 111.1981, A. L. Dyce (1♀, ANIC); Narrabri, Ag. Res. Sta. 21.xi.1965, W. E. Wright (1♀, ASCU); Pearl Beach, nr. Woy Woy, 9–11.xii.1988, J. A. MacDonald (1♀, ASCU); Queanbeyan, 2.7 km NE, 670m, 25.i.1979, 22.ii.1980, I.F.B. Common (1♁, 1♀, ANIC); Rydalmere, 30.xii.1967, Mercury vapor light (1♁, ASCU); Tarcutta, “Nundi”, 14.i.1958, D. E. McEachern (1♀, AMS); Wilton, CSIRO Exp. Farm, 12.i.1982, V. I. Robinson (1♁, AMS). QLD: Binna Burra, 27.xii.1969, R. Hardie (1♁, ANIC); Blackdown Tableland, Expedition Range, 5–6.xii.1979, MV light, G. Daniels (1♁, 1♀ QMB); Brisbane, 16.x.1911, H. Hacker (1♀, QMB); Brisbane, 28.xii.1919, A. J. Turner (1♀, QMB); Brisbane, 12.xii.1953, A. J. Jenkins (1♀, QMB); Brisbane, 20.x.1962, G. Monteith (1♀, QMB); Brisbane, 5.i.1965, A. E. May (1♁, QMB); Brisbane, 15.i.1972, W. Higham (1♀, QMB); Brisbane, 111.1983, D. Reeves (1♀, QMB); Bundaberg, 22 km. SW, (25°01’S, 152°13’E), 23.xi.1993, MV lamp, G. & A. Daniels (1♀, QMB); Caloundra, 4.i.1967, C. E. Chadwick (1♁, ASCU); Carnarvon Nat. Park, 8.xii.1979, mv lamp, G. Daniels, M. A. Schneider (1♁, QMB); Carnarvon Range, 20.xii.1938, N. Geary (1♀, AMS); Crows Nest, 1 km S (27°16’S, 152°03’E), 14.xii.1990, white light, T. Gush (1♁, ANIC); Kenmore, 17.xii.1957, at light, R. P. Kleinschmidt (1♁, QDAF); Lamington Nat. Pk., 4.ii.1966, S. Curtis (1♀, QMB); Lamington Nat. Pk. 11–17.ii.1967, G. B. Monteith (1♁, QMB); Leyburn, 5 km N (27°58’S, 151°38’E), 22.i.1988, mv 1amp, G. & A. Daniels (2♁♁, QMB); Mareeba, 24 km NbyW (16°47’S, 145°22’E), 24–25.xi.1981, J. Balderson (1♀, ANIC); Millstream Falls N. P. (17°39’S, 145°27’E), open forest, 21–27.xi.1998, at light, A. Calder (2♁ ♁ ♁, ANIC); Mt. Archer, Rockhamp-ton (23°20’S, 150°59’E), 24.xii.1993, mv lamp, G. & A. Daniels, R. Eastwood (1♁, 1♀, QMB); Mt. Cook Nat. Park (15°29’S, 145°16’E), 11–12.x.1980, T. Weir (1♁, 1♀, ANIC); Mt. Coolum (26°33’S, 153°05’E), 15.xii.1968, lights, Brtton & Misko (2♁♁, ANIC); Mt. Coo-tha (27°29’S. 152°57’E), 260m, open forest, 10.i.2002, 10350, MV Light, G. B. Monteith (5♁♁, QMB); Mt. Gannon summit, via West Burleigh, rainforest, 18.i.1987, G. Monteith, D. Cook (1♀, QMB); Mt. Hardgrave, 1 mi. SE (27°31’S, 153°28’E), 110m, 21.i.2002, MV light, Burwell, Wright & Cook (1♁, 1♀, QMB); Mt. Hypipamee (17°26’S, 145°29’E), 18–26.xi.1998, at light, A. Calder (1♀, ANIC); Nam-bour, 22.viii.1967, J. Donaldson (1♀, QDAF); Redcliffe, 30.xii.1937 (1♁, QDAF; 1♁ ANIC); Rolleston, 23 km S, 24.xi.1986, M. S. & B. J. Moulds (1♀, AMS); Sunnybank, 19.xii.1968, ex house (1♀, QDAF); Tamborine Mtn., 3.i.1931 (1♁, ANIC); Tarragindi, Brisbane, 14.xii.1957, at light, RPK (1♀, QDAF); Tinaroo Creek Rd., 13 km from Kennedy Hwy. (17°04’55.36”S, 145°30’30.07”E), 467m, 19.xi.2012, D. C. F. Rentz (1♁, 1♀. ANIC); South Pine River, 29.i.1928, H. Hacker (1♀, QMB); Toowong, 24.1.1958, at light, ARB (1♁, QDAF); Toringa, 23.xi.1961, ARB (1♁, QDAF); Woombye, 17.xii.1970, D. H. Colless (1♀, ANIC). SA: Adelaide, 25.i.1970, D. S. Rogers (1♀, QMB). WA: Bunbury, ix.1958, A. Snell (1♁, ANIC); John Forrest Nat. Park, Darling Ranges, 21.i.1971, MV lamp, G. A. Holloway, H. Hughes (1♁, AMS); Ludlow, 26.i.1925, J. Clark (1♁, ASCU).
Distribution. Widely distributed in Australia, but records lacking from Victoria and Tasmania.
Biology. Adults are almost always attracted to lights or light traps at night. Details of the biology of the Pinhole Borer in WA were given by Clark (1925), who illustrated the male, female and larva plus the type of wood damage. The relative rarity of adults in collections was explained by the fact that the beetles fly up to the canopy immediately after emerging from the burrow. Clark noted that in WA the hosts of this species included several myrtaceous trees, including Blackbutt (Eucalyptus patens Benth.), Tuart (E. gomphocephala DC.), Jarrah (E. marginata Donn ex Sm.), Wandoo (Eucalyptus wandoo Blakely), Flooded Gum (Eucalyptus rudis Endl.) and Marri (Corymbia calophylla (Lindl.) K.D. Hill & L.A.S. Johnson).
description: Published as part of Lawrence, John F., 2020, The Australian Lymexylidae (Coleoptera: Tenerionoidea) with one new genus and two genera new to Australia, pp. 211-238 in Zootaxa 4895 (2) on pages 228-230, DOI: 10.11646/zootaxa.4895.2.3, http://zenodo.org/record/4322473