Liogenys quadridens
Creators: name: Cherman, Mariana A.
name: Basílio, Daniel S.
name: Mise, Kleber M.
name: Frisch, Johannes
name: Smith, Andrew B. T.
name: Almeida, Lúcia M.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Melolonthidae
Liogenys
Liogenys quadridens

description: Liogenys quadridens (Fabricius, 1798)
Figs. 6, 9.
Melolontha quadridens Fabricius, 1798: 131 (original description).
Liogenys quadridens: Burmeister 1855: 14 (redescription); Harold 1869: 1140 (checklist); Bates 1887:155 (checklist); Dalla Torre 1913: 318 (checklist); Blackwelder 1944: 228 (checklist); Frey 1969: 50 (key); Evans 2003: 213 (checklist); Evans & Smith 2009: 181–182 (checklist); Krajčík 2012: 145 (checklist); Cherman et al. 2017: 11, 16; 2019: 62 (taxonomy).
Type material examined. Melolontha quadridens female lectotype, present designation (ZMUC): [white handwritten] “4 Dens.”, [white typeset] “zmuc / 00022369”, [white, outlined in red, typeset and handwritten] “ LIOGENYS / QUADRIDENS / (Fabricius, 1798) / LECTOTYPE / Des. Cherman M. A.”.
Additional material examined. PANAMA. Coclé: Río Hato, 22.V.1960, light trap, V.J. Tipton, 1 male, 1 female (CNCI). Panamá: Cerro Campana, 820 m, 8º40`N, 79º56`W, 22.V.1976, at blacklight, B.C. Ratcliffe, 2 males, 4 females (UNSM); Cerro Campana, 2600 feet, 10–20.V.1981, J.E. Wappes, 1 male, 1 female (UNSM). Panamá Oeste: Nueva Gorgona, 25.V.1962, R.&F. Zweifel, 1 male, 1 female (AMNH); Sajalices, 17.V.1982, E. Giesbert, 1 male, 3 females (UNSM). Veraguas: Santiago, 18.V.1977, H. Howden, 1 male (CMNC). VENEZUELA. Guárico: San Juan de Los Morros, 28.IV.1938, C.H. Ballou, 1 female (USNM); Monagas: El Tejero, 200 m, 2.V.1964, C. Bordon, 1 male (CMNC). Distrito Capital: Caracas, 1938, G. Vivas-R., 2 males (USNM). Without locality and date, E. Kummerow S., 1 female (ZMHB).
Diagnosis. Body light brown, elongate, males with sides parallel (Fig. 6A), females with sides slightly wider on posterior third (Fig. 6B); elytra light brown to yellowish brown, pronotum reddish to purplish brown, head even darker; clypeus quadridentate; clypeal emargination deep, rounded, and wide (Fig. 1A), slightly narrower in females than in males (Fig. 1B); distance between lateral and anterior clypeal teeth longer than basal width of one anterior tooth; angle between lateral and anterior clypeal teeth approximately 90º; mesotibia subquadrate in cross section; pygidium flat or slightly convex, pygidial disc glabrous, with scattered bristles on apex (Fig. 6D); males with protarsomere II less than twice the length of protarsomere I in dorsal view; parameres elongate, up to three times the length of their apex (Fig. 6H), inner margins straight, lateral expansion on outer margins along the parameres partially hidden in dorsal view (Fig. 1E), apex harpoon-shaped, lateral spine projected backwards, slightly convergent to the outer margin of the parameres; spine length slightly more than twice the length of the apex, subapical and proximal part of the apex elevated medially (Fig. 6), abruptly flattened distally at apex and spine (Fig. 6G).
Redescription. Length: 9.2–10.8 mm, width: 4.6–5.0 mm. Light brown to brown. Head: dark, distance between eyes nearly twice the width of one eye; frons equal in length to clypeus; clypeal emargination deep, rounded, and narrow; outer sides of anterior teeth parallel; outer margin of anterior teeth shorter than the eye in dorsal view; clypeus convex laterally and strongly produced forming a conspicuous, tooth-like projection; distance between lateral and anterior teeth longer than basal width of one anterior tooth, distance between lateral tooth and anterior margin of eye longer than one eye length, angle between anterior and lateral teeth approximately 90º; canthus exceeding or not the outer margin of the eye; distal maxillary palpomere maximum width twice the width at apex; fovea deep, extending past the transverse midline of the palpomere; antenna with 10 antennomeres, club lighter in color, as long as the funicle in females, longer than the funicle in males. Thorax: pronotal anterior margin slightly produced medially, undulate; disc glabrous, punctures sparse and fine in females, coarser in males; pronotal posterior corners rounded in males, apparently obsolete in females; hypomere with long bristles; mesepisternum scaly; anterior portion and sides of metaventrite with bristles; distance between mesocoxae and metacoxae nearly twice the length of the metacoxa; scutellum triangular, punctures mainly at the sides. Elytra: shiny, uniform yellowish brown to light brown, lighter in color than pronotum; elytra near three times longer than the pronotum; elytral suture slightly darker than elytron and not elevated; all four elytral ridges weakly defined. Legs: procoxa with long bristles on infra-carinal surface and fine scales and short bristles on outer surface; three protibial teeth, middle and apical equal in size, distance between basal and middle teeth longer than between middle and apical; protibial spur present; mesofemur with a row of long bristles on anterior and posterior margins, mesotibia quadrate in cross section, surface coarsely sculptured in females, finely sculptured in males, mesotibia with two transverse carinae, the apical carina complete in females, incomplete in males; metacoxa with bristles throughout and forming a row of scales parallel to the anterior margin (Fig. 6F); basal articular lobe of metacoxa produced beyond the outer margin of trochanter; inner margin of male metatibia carinate and produced on apex, apical inner surface with scattered bristles, metatibial disc coarsely sculptured; metatibial transverse carina and discontinuous longitudinal carina present posteriorly; metatarsomere I and metatarsomere II equal in length; males with protarsomere II as wide as it is long; protarsomeres and mesotarsomeres I–IV equally enlarged, wider than metatarsi; claw bifid, symmetrical, outer tooth of a claw longer and narrower than inner tooth; distance between teeth shorter than the inner tooth. Abdomen: disc of ventrites with sparse bristles; propygidium with bristles, pygidium flat, subtrapezoidal, wide, pygidial width exceeding distance between spiracles of propygidium; pygidial disc glabrous, few bristles on apex, coarsely punctate, roughly in males; slightly depressed medially in males; pygidial apex quadrate. Parameres: basal region slightly wider than both sections of the parameres at its midline; parameral split at 2/3 the length of the basal region; parameres almost three times the length of their apex; inner margins straight; lateral expansion of the outer margins partially hidden, visible from the midline up to the subapical portion; apex harpoon-shaped, lateral spine straight backwards, slightly bent, spine length more than twice the length of the apex, subapical and proximal part of the apex elevated medially, flattened distally at apex and spine (Figs. 1E, 6G). Parameres concave in lateral view (Fig. 6E).
Type locality. “ India Orientali” [Burmeister 1855: 14, misinterpreted locality of West Indies]. Species from Panama and Venezuela.
Geographic distribution. PANAMA (Coclé, Panamá, Panamá Oeste, Veraguas), VENEZUELA (Distrito Capital, Monagas).
Remarks. Liogenys quadridens was redescribed for the first time by Burmeister (1855), who transferred it from Melolontha Fabricius, 1775 to Liogenys. Fabricius (1798) mentioned in the original description that the species is from “ India Orientali” [East Indies], we interpreted that he meant West Indies instead. According to Burmeister (1855) and Harold (1869), L. quadridens occurs in Colombia and Guyana. Bates (1887) stated that this species occurs in “Amazons” but this record should be disregarded as it was surely based on the misidentification of other species of Liogenys. Bates (1887) also cited Panama, “Volcán de Chiriqui 2500 to 4000 feet (Champion)” but these specimens are here identified as L. quadridentata (based on our examination of these specimens in the BMNH). Frey (1969) cited the distributional limits of this species, from Florida (United States of America) (presumably based on port interception specimens) to Pernambuco (Brazil). In his key, Frey (1969) mentioned an intraspecific variation in the pronotal punctures and in the shape of the parameres, which he drew. At NHMB, we found the specimen from Pernambuco and it is here identified as L. piauiensis Cherman, 2017. Therefore, we refute the occurrence of L. quadridens in Brazil. Among the 41 specimens studied from seven collections bearing L. quadridens identification, we found one male from Nueva Gorgona (Panama) matching with the parameres drawn by Frey (1969), and a female of the same collection event which matches with L. quadridens lectotype.
Liogenys quadridens has been cited by the United States Department of Agriculture (1969, 1971, 1974) in its list of intercepted plant pests, carried by aircraft, in unknown hosts. The first time cited (1967–1968) it was being carried from Panama, and the following (1971–1972) probably from Venezuela (United States Department of Agriculture 1969, 1974). This species was also cited as a tomato plant host from Maracaibo, Venezuela (Morales- Valles et al. 2003), and there exists reports of this species in imported ripe tomato fruit throughout the European and Mediterranean Plant Protection Organization (EPPO) region. Nonetheless, as it is not likely to be transported in tomatoes it is classified non dangerous (Grousset et al. 2015). In a study on scarab beetles abundance of a tropical dry forest in Colombia, García-Atencia et al. (2015) found that L. quadridens was the most abundant species (1,667 individuals), characterized as an important pest of semestral crops in the Colombian Caribbean. After studying several specimens of the Caribbean region we cannot confirm that all those specimens mentioned on the previous works are L. quadridens. Although we do believe that L. quadridens occurs in Colombia (based on the known distribution in Panama and Venezuela), we did not examine any specimens to confirm this country record.
description: Published as part of Cherman, Mariana A., Basílio, Daniel S., Mise, Kleber M., Frisch, Johannes, Smith, Andrew B. T. & Almeida, Lúcia M., 2021, Liogenys Guerin-Méneville, 1831 (Coleoptera: Scarabaeidae: Melolonthinae Diplotaxini) of northern South America and Central America: taxonomic overview with four new species, pp. 201-226 in Zootaxa 4990 (2) on pages 214-215, DOI: 10.11646/zootaxa.4990.2.1, http://zenodo.org/record/5025886