Vatellus mexicanus Miller, 2005

Miller, Kelly B., 2005, Revision of the New World and south-east Asian Vatellini (Coleoptera: Dytiscidae: Hydroporinae) and phylogenetic analysis of the tribe, Zoological Journal of the Linnean Society 144 (4), pp. 415-510 : 459-466

VATELLUS MEXICANUS (SHARP, 1882) COMB. NOV.

Macrovatellus mexicanus Sharp, 1882b: 284 ; 1882a: 8; Zimmermann, 1920: 30; Leng, 1920: 76.

Type information: Holotype (by monotypy) ♂ in BMNH labelled, ‘ ♂ Mexico [handwritten on card with specimen]/Type [circular disc with red border]/Sharp Coll. 1905.-313./Type 442 mexicanus Mexico [handwritten]/B.C.A. Col. I. 2. Macrovatellus mexicanus, Sharp. [black line along top and bottom of label]/ Holotype [circular disc with red border]/ HOLOTYPE Macrovatellus mexicanus Sharp 1882 [red label with black line border].’ Two additional Sharp specimens accompany the holotype, but are not of the original type series as Sharp (1882b) indicated he had only the single male specimen. He included these other two specimens in his treatment of Central America ( Sharp, 1882a).

Type locality: Mexico.

Diagnosis: This species may be distinguished from other Vatellus by the following combination of characters: (1) dorsal and ventral surfaces distinctly alutaceous ( Fig. 5 ); (2) eyes large, protruding ( Fig. 131 ); (3) transverse pronotal crease distinctive ( Fig. 131 ); (4) male pro- and mesobasotarsomeres ( Fig. 135 ) much broader than in female ( Fig. 136 ); (5) apical lobe on abdominal sternum VI present but not strongly expressed ( Fig. 137 ); (6) male and female genitalia distinct ( Figs 140–146 ). This species is very similar to V. lateralis from which it is distinguishable by the median lobe broader and apically not deflexed or as strongly pointed. In addition, the intermediate duct between the spermatheca and receptacle is shorter and not strongly sinuate. The lateral lobes end well short of the apex of the median lobe in V. lateralis ( Fig. 139 ) whereas in V. mexicanus the apices of the lateral lobes extend to or beyond the apex of the median lobe ( Fig. 140 ).

Description:

Habitus. Lateral outline strongly discontinuous in dorsal aspect, lateral elytral margins strongly rounded ( Fig. 131 ), not dorsoventrally flattened. Measurements are given in Table 1.

Coloration. Head yellow; pronotum brown, irregularly yellow along anterior and lateral margins; elytron dark brown to yellow-brown with yellow maculae subapically and laterally along margins, basally with few yellow maculae ( Fig. 131 ); venter and appendages red brown to light brown, infuscate, especially laterally on metacoxae.

Sculpture and structure. Head with punctation distinct, variable in size, coarse medially between eyes, becoming finer anteriorly, interpuncture surfaces smooth, shiny to slightly microreticulate, surface posterior to eyes alutaceous, rough; anterior clypeal margin rounded; eyes large, strongly protruding. Pronotum densely punctate, but punctures strongly obscured by rough, alutaceous sculpturing, surface as in Figure 5 , pale setae moderately long; pronotum cordate, lateral pronotal margin rounded anteriorly, broadest near anterior angles, posterior angles acute; lateral bead obscured; transverse sulcus distinctly impressed. Elytron with punctation dense but edges of punctures strongly obscured by dense alutaceous sculpturing as on pronotum ( Fig. 132 ), light setae moderately dense and conspicuous. Prosternum short, roughly sculptured, glabrous; prosternal process broad with distinctly rounded medial carina, lateral margins rounded, apex triangularly produced, glabrous, apex pointed. Metasternum with punctation dense laterally, punctures large and shallow, somewhat obscured by alutaceous sculpturing; anteromedial margin slightly produced ventrally. Abdominal sternal sutures not unusually modified; sterna with punctation dense over entire lateral surface, finer medially, obscured by alutaceous sculpturing; sixth abdominal sternum with apical lobe inconspicuously produced, triangular, not strongly produced; speleum broad basally, sides strongly convergent, apex moderately rounded, not strongly curved. Metacoxae with lateral portion densely punctate over entire surface, punctures shallow, somewhat obscured by alutaceous sculpturing; metacoxal lines strongly approximate posteriorly, strongly divergent anteriorly; medial portion moderately punctate, punctures finely setose. Metatrochanter rounded, offset; metatarsal claws dentate.

Male genitalia. Median lobe in lateral aspect evenly but not strongly curved, relatively narrow, narrowed subapically, apex slightly curved dorsally and narrowly rounded, basal portion elongate, slender, without subapical spines ( Figs 141, 144 ); in ventral aspect narrow apically, broader basally, lateral margins convergent, apex narrowly rounded ( Fig. 142 ). Lateral lobe broad to broadly rounded apex, with large region of fine, dense, elongate setae; stout subapical setae absent ( Fig. 143 ).

Female genitalia. Gonocoxosternite broad, robust, medial margin very broad, apical angle about 90∞; anterior margin concave; anterior lobe moderately long, moderately broad ( Fig. 145 ). Gonocoxa very broad, about as long as wide, apex obtusely rounded, apodeme moderately narrow, about as long as main portion, numerous setae along apicoventral margin and on dorsal surface, ventral surface with large region of semicircular striae with very short, spinous, adpressed setae ( Fig. 145 ). Bursa copulatrix moderate in size, with four distinct, finger-like lobes; spermathecal duct relatively short, relatively narrow; receptacle spherical, nearly equal in size to spermatheca ( Fig. 145 ); intermediate duct moderately long, relatively straight ( Fig. 146 ); spermatheca nearly spherical, triangular process very broad; fertilization duct short, curved ( Fig. 145 ).

Sexually dimorphic characters. Male with poorly developed mesotrochanteric and mesofemoral brushes of setae, broad with lateral portions longer forming an elongate cup-shaped structure. Male with protarsomeres 1–3 ( Fig. 135A ) substantially broader than in female ( Fig. 136A ), protarsomere III distinctly shorter than in female; mesotarsomeres of male ( Fig. 135B ) broader than in female ( Fig. 136B ), but not conspicuously so; male mesotarsomere III ( Fig. 135B ) not much longer than mesotarsomere III ( Fig. 136B ).

Intraspecific variation. This species varies significantly in size. A series from Belize ( USNM) is nearly entirely black with the maculae nearly absent.

Natural history: Vatellus mexicanus has been collected from black lights. It has also been collected from a variety of habitats including dry tropical forest, clear pools in a stream bed, pools in a temporary stream, a shallow pool in a gravel pit and a stock pond. In Texas the species occurs in permanent or temporary ponds with grassy margins ( Jasper & Challet, 2002).

Distribution: This species is widespread along the western and eastern low areas of Mexico and is also known from Belize and Costa Rica ( Fig. 312). Although Leech & Chandler (1956) speculated the species may occur in southern California, it has not been collected there though it is known from the northern Baja Peninsula and northern Sonora. Recently, V. mexicanus was reported from Dimmit, LaSalle and Zapata Counties, Texas, USA ( Jasper & Challet, 2002).

Phylogenetic relationships: This species is sister to a clade of several very similar species ( Fig. 316 ). These species are similar in overall shape, the presence of distinct maculations, similar cuticular microsculpturing ( Fig. 5 ) and shape of the male median lobe.

Material examined: Belize: Cayo Dist. San Ignacio (8 km S), 23 May 1986, stock pond, P.J. Spangler, R.A. Faitoute (30, USNM) . Costa Rica: 16 mi S La Cruz , 13 July 1965, PJ Spangler (6, USNM) ; Finca Jenny , 30 km N de Liberia, Prov Guana , 240 m, 14 April 1993, E Araya (30, JBWM) ; Guanac. Est. Sta. Rosa , 300 m LN 313000, 359300, black light in dry tropical forest, D.A. Pollock (2, LHIC) ; Guanacaste, Palo Verde Nat Park , 10∞20¢43≤N 85∞16¢24≤W, 8 June 2000, shallow pool, gravel pit, RE Roughley (3, JBWM ; Playa Naranjo, Sta Rosa , PN Guanacaste Prov Guan, March 1991, E Alcazar (13, JBWM) ; Santa Rosa , 1 March 1993, K.G. Bernhardt (5, LHIC) ; Santa Rosa N P, Guanacaste , 23 May 1980, DH Janzen and W Hallwachs (1, JBWM) ; Sector Cerro Cocori, Fca. De E Rojas, 150 m, Prov. Lamon , March 1993, E Rojas (1, JBWM) . Mexico: Baja Calif. Sur, San Bartolo Dam , 1 May 1947, I LaRivers (1, USNM) ; Baja California, Gulf of California , Isla del Carmen , 19–20 July 1984, SE Miller (1, USNM) ; Baja California Sur , 3 mi W Agua Caliente, 22 August 1997, WD Shepard (1, LHIC) ; Campeche 21 mi E Campeche, 27 July 1964, P.J. Spangler (2, USNM) ; Chis. 4 mi W Cuahtemoe, 30 August 1963, JR Zimmermann (1, USNM) ; Chis. 5 mi S Las Cruces, 23 August 1965, PJ Spangler (1, USNM) ; Chis. Chipa de Corzo , 4 mi E, 1 November 1963, JR Zimmermann (1, USNM) ; E. of Chiapas , 5 August 1957, D. Lauck (16, USNM) ; Jalapa , 10 mi E, 27 August 1962, JR Zimmerman (1, USNM) ; Jalsico , La Huerta, 3.5 mi N, 22 March 1971, JR Zimmerman (1, USNM) ; Lower California, San Felipe , 1926, JD Sherman (1, USNM) ; Morelus, nr Tigolna , 22 June 1963, R Woodruff (5, FSCA) ; Nayarit San Blas , 26 July 1963, PJ Spangler (48, USNM) ; Nayarit, San Blas , 5 mi E, 31 July 1962, JR Zimmerman (1, USNM) ; Nuevo Leo, Puente Critsolinas , 17 mi S Monterey, 19 July 1969, FN Young (1, FSCA) ; Oaxaca, Juchitan , 3 mi E, 7 September 1964, JR Zimmerman (1, JBWM) ; Oaxaca, Juchitan , 3 mi E, 7 September 1964, JR Zimmerman (1, USNM) ; Oaxaca, Salina Cruz , 6 September 1964, JR Zimmerman (1, USNM) ; Oaxaca, Tehuantepec , 2 September 1963, JR Zimmerman (4, USNM) ; Oaxaca, Tehuantepec , 11 June 1964, JC and D Pallister (2, AMNH) ; Oaxaca, Zanatepec , 22 July 1964, P.J. Spangler (14, USNM) ; Oaxaca, Zanatepec 8 km E, 23 May 1981, pools in temp stream, PJ Spangler (1, USNM) ; Puebla, nr Maria Andres , 10 September 1964, JR Zimmerman (1, USNM) ; San Luis Potosi , 12 mi S Cd. Mante, 21 June 1975, CA Triplehorn (1, FSCA) ; San Luis Potosi, 15 mi E C del Maiz , 19 November 1948, HB Leech (1, FSCA) ; San Luis Potosi , 29 mi N Valley, 19 August 1954, FN Young (1, FSCA) ; San Luis Potosi, Antiguo Morelos , 23 March 1963, JR Zimmerman (1, USNM) ; San Luis Potosi, Ciudad Valles, 22 August 1964, PJ Spangler (18, USNM) ; San Luis Potosi, Comcoa, Rio Axtla , 23 March 1963, JR Zimmerman (1, USNM) ; San Luis Potosi, El Salto Falls , 14 June 1963, black light, RE Woodruff (1, FSCA) ; Sinaloa , 54.0 mi S Culiacan, 23 April 1969, 540¢, ME Irwin (1, USNM) ; Sinaloa , 7 mi N Rosario, 24 July 1963, PJ Spangler (5, USNM) ; Sinaloa, Concordia , 8 mi E R15, 12 December 1962, JR Zimmerman (1, USNM) ; Sinaloa, Culiacan , 21 July 1959, at light, 250¢, HE Evans (1, FSCA) ; Sinaloa, Elota , 1 mi S, 01 August 1962, JR Zimmerman (1, USNM) ; Sinaloa , pools in stream, 6 mi w El Limon, 21 June 1965, FN Young (1, FSCA) ; Sonora, 13 m SE Alamos , 30 October 1972, K Stephens (3, FSCA) ; Sonora , 20 mi W Moctequma, 28 September 1980, RD Gordon (1, USNM) ; Sonora, Alamos , 15 July 1963, PJ Spangler (2, USNM) ; Sonora, Alamos , 17 September 1980, R. Gordon (1, USNM) ; Sonora, Moctezuma 14 mi W, 27 September 1974, clear pools in stream bed, JR Zimmerman (1, USNM) ; Sonora, Rio Moccsorito Arroyo Huerta , 24 June 1971, R Vijenhoes (1, FSCA) ; Tamaulipas , 4 mi N Ciudad Mante, 3 September 1964, DR Whitehead (1, USNM) ; Tamaulipas, Limon Rio Frio on Nat. Hgw. , 18 December 1940, FN Young (20, FSCA) ; Tamaulipas, Limon, Rio Frio on Nat Hgw , 18 December 1940, FN Young (1, USNM) ; Tamaulipas, Llera , 20 mi S, 24 March 1963, JR Zimmerman (1, USNM) ; Tamaulipas, Nuevo Morelos , 28 August 1965, PJ Spangler (1, USNM) ; Tamaulipas, Rio Guayalejo nr Magiscatzin , 11 June 1960, FN Young (6, FSCA) ; Tamaulipas, San Jose , April 1910, JD Sherman (1, USNM) ; Tehuantepec , A Boucard (4, MNHN) ; Vera Cruz, Puente Nacional , Flint and Ortiz (2, USNM) ; Veracruz , 15 mi SE Tantoyuca, 28 August 1965, PJ Spangler (6, USNM) ; Veracruz, Cuitlahuac , 10–12 August 1964, PJ Spangler (75, USNM) . United States: (all from Jasper & Challet, 2002), Texas, Dimmit Co., Chaparral WMA, pond in SW Plot 3 W, Rat- tlesnake Hill , 25 March 2000, SK Jasper (9, TAMU) ; Chaparral WMA, Seco Pond , 26 March 2000, SK Jasper (3, TAMU) ; LaSalle Co., Chaparral WMA, pon in SW Plot 14, Rosindo Laguna , 25 March 2000, SK Jasper (1, TAMU) ; LaSalle Co., Chaparral WMA, Scotty Pond , 26 March 2000, SK Jasper (1, TAMU) ; Zapata Co., Stream at US 83, 5.4 mi N TX16, 18 June 1999, SK Jasper (6, TAMU) .

VATELLUS MACULOSUS MILLER SP. NOV.

( FIGS 147–160 , 311 )

Type information: Holotype ♂ in USNM labelled, ‘ VENEZUELA Guar.,15 Km.S. Calabozo II-9-13-1969

P. & P.Spangler/Collected in Lago deLosPatos/HOLO- TYPE Vatellus maculosus Miller 2004 [red label with double black line border].’

Paratypes: 2 in USNM labelled same as holotype. Colombia: Meta, 10 km S Villavicencio , P and P. Spangler (3, USNM) . Guyana: Rupununi R. Wichabai, 23 April 1961, shady pool, cut off from river in dry season, stony bottom with much leaf debris; <1 ft deep, 10 yds diam, RH McConnel (2, BMNH) . Venezuela: Guarico, 15 km S Calabozo, Lago de los Patos, P and P. Spangler (2, USNM) .

Type locality: Venezuela, Guarico, 15 km S Calabozo, Lago de los Patos.

Diagnosis: This species may be distinguished from other Vatellus by the following combination of characters: (1) dorsal and ventral surfaces distinctly alutaceous, punctures obscured, elytral surface sculpture as in Figure 5 ; (2) eyes large, protruding ( Fig. 147 ); (3) transverse pronotal crease distinctive ( Fig. 147 ); (4) male pro- and mesobasotarsomeres ( Fig. 151 ) much broader than in female ( Fig. 152 ); (5) apical lobe on abdominal sternum VI present but not strongly expressed ( Fig. 153 ); (6) male and female genitalia distinct ( Figs 155–160 ). This species is mainly separable from similar species, V. mexicanus , V. lateralis and other similarly alutaceous species, by the shape of the apex of the male median lobe, which is rounded and distinctly constricted subapically ( Fig. 155 ).

Description:

Habitus. Body outline strongly discontinuous in dorsal aspect, lateral margins of elytra strongly rounded ( Fig. 147 ), not dorsoventrally compressed. Measurements are given in Table 1.

Coloration. Head yellow; pronotum brown medially and along anterior and posterior margins, yellow to yellow-brown laterally; elytron dark brown with lateral and apical yellow maculae, basally with broad, irregular yellow band on most specimens, some with basal band reduced to few, small maculae ( Fig. 147 ); venter yellow to yellow-brown, darker on mesocoxae and metasternum; appendages yellow to yellow-brown.

Sculpture and structure. Head densely and finely punctate medially, nearly impunctate anteriorly on frons and clypeus, surface between punctures very finely microreticulate, shiny; anterior clypeal margin rounded; eyes moderately large, protruding. Pronotum densely punctate, punctures shallow and obscured by microreticulation and alutaceous, rough surface microsculpture, short, fine, pale setae present; pronotum broadest submedially, not strongly cordate, lateral margin only shallowly rounded along anterior half, posterior angles slightly obtuse to right-angled ( Fig. 147 ); lateral bead obscured; transverse sulcus distinct, mainly laterally ( Fig. 147 ). Elytron finely and densely punctate ( Fig. 148 ), punctures shallow and obscured by alutaceous, rough surface as on pronotum, punctures even more obscured apically, each puncture with short, fine, pale seta. Prosternum rough, glabrous; prosternal process broad, flat, lateral margins rounded, apex broadly pointed, glabrous. Metasternum finely punctate, punctures obscured by alutaceous surface texture; anteromedial margin not swollen, pointed medially. Abdominal sterna finely punctate over entire surface, punctures nearly obliterated by alutaceous surface texture; sixth sternum with apical lobe well developed, flattened, apically rounded ( Fig. 153 ); speleum moderately broad, basally narrowed to narrowly rounded apex, slightly curved dorsally at apex ( Fig. 154 ). Metacoxa with lateral portion very finely punctate, punctures nearly obliterated by alutaceous surface texture; metacoxal lines only moderately approximated posteriorly, broadly divergent anteriorly ( Fig. 149 ); medial portion alutaceous. Metatrochanter moderately rounded, somewhat elongate and offset ( Fig. 150 ); metatarsal claws finely dentate.

Male genitalia. Median lobe in lateral aspect slightly curved throughout length, medially expanded with dorsal margin less strongly curved than ventral margin, basal portion very long, narrow; apex constricted slightly subapically ( Fig. 155 ), apex rounded, with numerous minute spinous setae subapically ( Fig. 158 ); in ventral aspect broader in basal half, narrowed medially and relatively evenly narrowed to pointed apex ( Figs 156, 158 ). Lateral lobe broad, apex relatively straight, apex slightly expanded, apically very broadly rounded, with very dense region of setae at apex ( Fig. 157 ).

Female genitalia. Gonocoxosternite moderately broad, apical angle acutely rounded, anterior margin somewhat concave, anterior lobe long, broad, apically broadly rounded ( Fig. 159 ). Gonocoxa elongate, slen- der, apex moderately narrowly rounded, apodeme long and slender ( Fig. 159 ). Bursa copulatrix very broad, irregularly punctate and striate anteriorly ( Fig. 159 ); spermathecal duct long, slender; receptacle spherical, approximately half size of spermatheca; intermediate duct short, relatively straight ( Fig. 160 ); spermatheca moderately elongate, curved, anterior portion subspherical and large, posterior portion narrowed posteriorly; fertilization duct very short ( Fig. 159 ).

Sexually dimorphic characters. Brushes of setae on mesotrochanter and mesofemur of male well-developed, that of mesofemur elongate and cup-shaped in form. Male with pro- and mesobasotarsomeres ( Fig. 151 ) very distinctly broader than in female ( Fig. 152 ); female protarsomere III ( Fig. 152A ) distinctly longer than in male ( Fig. 151A ).

Intraspecific variation. This species varies in the extent of pale maculation on the elytron and pronotum. In most specimens the pronotum is nearly entirely pale and the elytron has a broad transverse subbasal band of yellow, but in at least one of the specimens studied the pronotum is nearly entirely dark brown and the basal elytral macula is restricted to the lateral margin.

Natural history: Vatellus maculosus has been collected from a shady pool with a mineral substrate and much leaf debris.

Distribution: This is a northern South American species with specimens known from Colombia, Guyana and Venezuela ( Fig. 311 ).

Phylogenetic relationships: This species is part of the clade containing species similar to V. mexicanus ( Fig. 316 ). However, within this group this species does not have clear affinities with any other particular species.

Etymology: This species is named maculosus, Latin for ‘spotted’, in reference to the maculate elytral coloration.

Figures

Figure 311. Vatellus species, distribution. - = V. lateralis, Δ = V. maculosus, • = V. sahlbergi.

Figures 2–7. Vatellini species, morphology. 2–5, elytral sculpture; 2, Vatellus grandis; 3, V. tarsatus; 4, Derovatellus lentus; 5, V. mexicanus. 6–7, Vatellus species, crania, lateral aspect; 6, V. grandis; 7, V. mexicanus.

Figures 131–138. Vatellus mexicanus. 131, dorsal habitus; 132, elytral sculpture in area indicated on habitus by dotted square; 133, medial portion of metacoxae; 134, metatrochanter and metafemur, anterior aspect; 135–136, tarsomeres, dorsal aspect; 135, male; 136, female, A, protarsus; B, mesotarsus; 137, sternum VI, ventral aspect; 138, speleum abdominal sterna V, VI, dorsal aspect.

Figures 139–146. Vatellus species. 139, Vatellus lateralis, apices of median and right lateral lobes of aedeagus, right lateral aspect; 140–146, Vatellus mexicanus; 140–144, male genitalia; 140, apices of median and lateral lobes of aedeagus, right lateral aspect; 141, median lobe, right lateral aspect; 142, median lobe, ventral aspect; 143, right lateral lobe, lateral aspect; 144, apex of median lobe, right lateral aspect; 145-146, female genitalia; 145, ventral aspect; 146, spermatheca and associated structures, dorsal aspect.

Figures 315–316. Vatellini species, consensus cladograms. 315, Consensus cladogram of 72 most parsimonious cladograms (length = 78, CI = 67, RI = 92) resulting from cladistic analysis of Vatellini including Calicovatellus petrodytes. 316, Consensus cladogram of five most parsimonious cladograms (length = 74, CI = 70, RI = 93) resulting from cladistic analysis of Vatellini not including Calicovatellus petrodytes. Numbers above branches are Bremer support values.

Figures 147–154. Vatellus maculosus. 147, dorsal habitus; 148, elytral sculpture in area indicated on habitus by dotted square; 149, medial portion of metacoxae; 150, metatrochanter and metafemur, anterior aspect; 151–152, tarsomeres, dorsal aspect; 151, male; 152, female, A, protarsus; B, mesotarsus; 153, sternum VI, ventral aspect; 154, speleum abdominal sterna V, VI, dorsal aspect.

Figures 155–160. Vatellus maculosus. 155–158, male genitalia; 155, median lobe, right lateral aspect; 156, median lobe, ventral aspect; 157, right lateral lobe, lateral aspect; 158, apex of median lobe, ventral aspect; 159–160, female genitalia; 159, ventral aspect; 160, spermatheca and associated structures, dorsal aspect.