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Rediscovery of tetraolytta gerardi (PIC) (Coleoptera: Meloidae), an enigmatic blister beetle from Brazil : Redescription and taxonomic placement PDF

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Preview Rediscovery of tetraolytta gerardi (PIC) (Coleoptera: Meloidae), an enigmatic blister beetle from Brazil : Redescription and taxonomic placement

PROC. ENTOMOL. SOC. WASH. 109(4), 2007, pp. 765-772 REDISCOVERY OF TETRAOLYTTA GERARDI (PIC) (COLEOPTERA: MELOIDAE), AN ENIGMATIC BLISTER BEETLE FROM BRAZIL: REDESCRIPTION AND TAXONOMIC PLACEMENT Marco A. Bologna and John D. Pinto (MAB) Dipartimento di Biologia, Universita Roma Tre, Viale Marconi 446, 00146 Roma, Italy (e-mail: [email protected]); (JDP) Department of Entomology, University of California, Riverside, U.S.A.; current address: P.O. Box 2266, OR Waldport, 97394, U.S.A. (e-mail: [email protected]) — Abstract. The monotypic genus Tetraolytta Pic, endemic to southern Brazil, has remained virtually unknown since its description. Previously assigned to the subfamily Meloinae near the genus Lytta Fabricius, the examination ofthe holotype of T. gerardi, its type species, as well as recently collected material, clearly shows the genus belongs to the Tetraonycinae close to Tetraonyx Latreille. This paper includes a redescription of Tetraolytta gerardi and a discussion of its position relative to the other genera ofTetraonycinae. The species is recorded developing in the nests ofthe bee Monoeca haemorrhoidalis (Smith) (Apidae). Key Words: taxonomy, Tetraolytta, Tetraonycinae, Neotropics The monotypic Tetraolytta Pic has correct name, Tetraolytta, but returned it remained one of the most poorly known as a subgenus of Lytta. Finally upon taxa of Meloidae in the New World. Pic examining a specimen of T. gerardi from (1919) described the type species, Lytta southern Brazil and impressed by its gerardi Pic, from a single specimen, distinctiveness and lycid-like phenotype. without providing details on its distribu- Denier (1940) again elevated Tetraolytta tion (assumed to be from South Amer- to genus level. Although not discussing ica) and referred it to a new subgenus its taxonomic placement in that paper, it Tetraolytta. With only Pic's original is clear that Denier continued to consider description available. Denier, in a series T. gerardi as related to Lytta (Meloinae: of papers, proposed varying and confus- Lyttini). The systematic position of ing taxonomic treatments of Tetraolytta. Tetraolytta has remained questionable. Considering the name inappropriately Pinto and Bologna (1999) suspected formed, he originally introduced an un- a relationship to the Tetraonycinae, but necessary replacement name, Picella De- continued to treat the genus as a lyttine nier. Although initially continuing to pending further study. treat Picella as a subgenus (Denier Until now, only Pic and Denier had We 1933a: 37, note 1), in the same paper examined specimens of T. gerardi. (p. 47) and a subsequent contribution have now had the opportunity to study (Denier 1933b) he elevated it to a genus recently collected material from southern close to Lytta Fabricius. Then, in his Brazil, as well as its type, thereby catalogue (Denier 1935), he used the allowing us to confirm our previous — 766 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON suspicions oftetraonycine affinity. Here- Taxonomic Treatment in we redescribe and figure Tetraolytta Subfamily Tetraonycinae gerardi, formally transfer the species to the Tetraonycinae, and discuss its place- Tetraonycinae, a strictly New World ment within the subfamily. The host of subfamily, now includes four genera: Tetraolytta, previously unknown, also is Meloetyphlus ^aXevhowsQ 1872, Opiome- loe Selander 1985, Tetraolytta Pic 1919, recorded. Tetraonyx Latreille 1805, all placed in a single tribe, Tetraonycini (synonym: Material Examined Meloetyphlini Borgmeier 1937). The redescription of the monotypic Diagnosis. Adult: Maxillary galea Tetraolytta is based primarily on the unmodified. Pronotum with lateral mar- male holotype of its type species de- gins of disk abruptly declivant to lateral posited in the Pic Collection (Museum surfaces. Tarsal claws without teeth, National d'Histoire Naturelle, Paris, consisting of two curved blades of France). The type is well preserved subequal width. Tarsi with penultimate except for absence of both hind tarsi. segment generally as wide as long, that The holotype has the following labels: (a) on at least foretarsus usually bilobed and "72" (small, square, light blue, printed), wider than long. Male with sternum VII (b) ''Tet/iaonyx (sic!) sp. desire" (rectan- (5th visible) emarginate; sternum IX Y- gular, white, handwritten by Pic), (c) shaped, relatively short; tergum IX con- "type" (small, rectangular, white, hand- sisting of two lateral tergites. Male written by Pic), (d) "TYPE" (rectangu- genitalia with gonostyli fused only at lar, red, printed, not contemporary), (e) base and to varying degree with gono- "? Lytta Petami Pic" (rectangular, white, coxal piece; aedeagus with a single api- handwritten by Pic), (f) "sg. Tetraolytta cally placed dorsal hook present or not; Pic" (rectangular, white, handwritten by endophallic hook present and robust Pic). One of us (MAB) added the First instar larva: Phoretic. Navicular. following label: (g) '"Tetraolytta gerardi Head capsule with internal phragma at (Pic), M. Bologna det. 2003." The name midline. Labial palpi absent. Spiracles of gerardi was used upon description ofthe abdominal segment I greatly enlarged, species (Pic 1919) but evidently never projecting above surface, pedunculate. physically applied to the type. Larvae of only Tetraonyx and Meloe- Six additional specimens ofthis species typhlus are known (MacSwain 1956, also were studied. Collection data are Bologna and Pinto 2001). — as follows: Brazil (Parana); Mananciais Comments. Placement of Tetraony- da Serra Reserve; Piraquara; 25°29'S, cini within Meloidae has varied. It 48 59'W (1,029 m); 24-ix/29-x-2005; Ar- usually has been treated as a tribe of madilha de Emergencia 1, Area A; Nemognathinae (Selander 1983, 1985), Leo Correia da Rocha Filho, collr. or a distinct subfamily (MacSwain 1956, Beetles were collected as they emerged Pinto and Bologna 1999). A recent from the nests of the wild bee, Mono- phylogenetic study of the family based eca haemorrhoidalis (Smith) (Apidae). largely on first instar larval morphology These specimens are deposited in the (Bologna and Pinto 2001) supports sub- Bologna Collection, Universita degli family status and hypothesizes a sister Studi "Roma Tre," Rome, and the group relationship to Nemognathinae. Department of Entomology Research The short, bilobed tarsomeres distin- Museum, University of California, guish adult Tetraonycinae from other Riverside. subfamilies, except some species of the VOLUME NUMBER 109, 4 767 primitive Eleticinae. Structure of the broad, length of III-X not exceeding c. male genitalia and claws further distin- 2X segment width; XI distinct, elongate, guishes them from the Nemognathinae twice as long as I and III, respectively in (Selander 1965). The internal cephalic male, abruptly narrowed near midlength phragma, absence of labial palpi, and in both sexes; sexes varying slightly in structure ofthe first abdominal spiracles segment proportions but otherwise an- separate tetraonycine first instar larvae tennae not dimorphic. Elytra planate from all other Meloidae (MacSwain somewhat widened posteriorly. Hind 1956, Bologna and Pinto 2001). wings fully developed. First tarsomere Meloetyphlus, Opiomeloe and Tetrao- of middle and hind legs elongate, length lytta are monotypic; Tetraonyx is a large ofmetatarsomere I c. 1/2 length ofentire genus with 102 species (Selander 1983, tarsus. Aedeagus with one hook posi- Selander and Martinez 1984, Selander tioned at apex; endophallic hook well and Selander 1992). The subfamily is sclerotized. primarily Neotropical with relatively few Tetraonyx reaching the southern Nearc- Tetraolytta gerardi (Pic 1919) tic (Selander 1983, 1985; Pinto and (Figs. 1-9) Bologna 1999). Tetraonyx has neverbeen revised and most species are unknown to Lytta (Tetraolytta) gerardi Pic 1919: 3; current workers. The only key to species, Denier 1935: 163. published over 120 years ago (Haag- Tetraolytta gerardi: Denier 1940: 802; Rutenberg 1879), is not only outdated Pinto and Bologna 1999: 592. but was incomplete at its inception (Selander 1983). Genus Tetraolytta Pic 1919 Lytta {Tetraolytta) Pic 1919: 3; Denier 1935: 163. Type species: Lytta {Tetra- olytta) Pic, by monotypy. Picella Denier 1933a: 37 note 1 (as subgenus), p. 47 (as genus); 1933b: 237-8, 241 (as genus). Unnecessary replacement name (obj. jun. syn. of Tetraolytta). Tetraolytta: Denier 1940: 802; Pinto and Bologna 1999: 592. — Diagnosis. Elongate, moderately slen- der, superficially resembling Lycidae. Primarily black except orange laterally on pronotum and basal section ofelytra. Head distinctly wider at eyes than at tempora, tempora not inflated; frons distinctly concave with a large smooth elongate bulla medially. Eyes large, immediately behind antennal sockets and above base of mandibles. Antenna not clavate, elongate, c. 0.7X elytral length in male, segments relatively Fig. 1. Tetraolytta gerardi, female. PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON 768 Figs. 2-9. Tetraolytta gerardi, male holotype. 2, Head and pronotum, dorsal view (densely stippled portions near center of both structures represent elevated areas). 3, Last three antennomeres. 4, Tarsomeres I-IV of foreleg. 5, Last visible sternum. 6, Sternum IX, spiculum gastrale. 7, Gonostyli, ventral view. 8, Gonostyli, lateral view. 9, Aedeagus, lateral view. Bar = 1.0 mm (2), or 0.5 mm (3-9). — Redescription. Based on all available coloration on pronotum and elytra. material. The states of certain variable Black or dark brown except apical features including those characterizing margin of labrum orange, clypeus with the holotype are given in the Variation a subapical transverse orange to light section below. brown band, maxilla, labium and gular Male. Length: 15-16 mm. Color: Gen- area varying from dark to orange brown; erally black with considerable orange pronotum orange with a broad percur- VOLUME NUMBER 109, 4 769 rent black medial stripe, width of stripe 0.66-0.70 as long as wide, widest at base, equal to or slightly greater than greatest lateral margins of disk subparallel, very scutellar width, stripe tapering poste- slightly sinuate and broadly ridged from riorly or not; scutellum black; forecoxa, base to anterior 1/3, then abruptly prosternum, meso- and metapleural rounded and convergent to apex; disk areas varying from dark to orange usually with dense and relatively small brown; elytra orange at anterior 1/2, punctures, highly uneven, middle area black posteriorly, black coloration ex- elevated, convex, lateral areas depressed, tending further anteriorly along suture most distinctly so in basal 2/3, with and orange coloration narrowly extend- a relatively deep suboval depression on ing posteriorly along lateral margin to each side connected via a transverse a varying degree but never more than 1/2 furrow near basal margin; lateral sur- length of black section; hind wing dark faces of pronotum almost perpendicular brown except subhyaline at basal 1/5. to disk, smooth, without punctures or Vestiture relatively dense and moderately setation. Scutellum broadly linguiform, elongate dorsally but not obscuring with a shallow sulcus along midline, apex cuticle, setation color generally as that weakly emarginate. Mesosternum pos- of underlying cuticle (black or orange) teriorly depressed and sub-triangularly with some mismatching on pronotum, elongate; mesepisterna and metasternum scutellum and base of elytra. Head wide. Elytra slightly widened posteriorly, (Fig. 2): Distinctly narrower than pro- discal surface relatively planate, surface notum (0.7-0.8X as wide), 0.8X as long rugulose. Hind wing as in Tetraonyx as wide, width at tempora 0.9X greatest frontalis Chevrolat, 1833 (Kaszab 1959, width at eyes; eye large, notched in fig. 56) except M2 (= RP) only extending dorsal 1/2, placed immediately behind c. 1/2 as far into radial field, and Al (= antennal sockets; clypeus and labrum M3+4) not connected to CU (= medial somewhat reclinate to head capsule; bar). Legs unmodified, relatively slender; labrum extending well beyond 1/2 length all tibiae with two apical spurs, posterior of mandible, slightly emarginate; head foretibial spur slightly longer, mid- and capsule densely punctate, punctures hind tibial spurs subequal in length, hind small, less dense on vertex and occiput tibial spurs spatulate with inner spur than on frons, vertex and frons moder- parallel sided and outer spur widening ately concave, with an elongate, moder- slightly to apex. Middle tibia bowed, ately large levigate bulla on frons be- posterior surface slightly concave from tween eyes; frons more distinctly concave base to apex. Tarsi (Fig. 4) with first and below eyes, elevated laterally and over- last segments relatively elongate and lapping base of antennae; occiput with slender, penultimate segment shortest narrow longitudinal furrow at middle; and bilobed, antepenultimate segment mandible strongly curved at apical 1/2; slightly longer and more weakly bilobed; palpi unmodified. Antenna elongate relative length of fore-, mid- and hind (Fig. 3), relatively robust; length/width tarsal segments as follows:17/9/7/6/15, ofsegments I-XI = 1.6, 0.6, 1.6, 1.9, 1.8, 12/6/4/3/8, 25/8/5/14; all tarsal segments 2.1, 2.2, 2.0, 2.2, 2.2, 4.4; length of III except I with light colored setation subequal to I, segments IV-X each beneath, these most dense on segments slightly longer than III, XI c. 2X length II-IV of fore- and midlegs and II III of of III and I, respectively, XI abruptly hind legs, relatively sparse on ultimate narrowed from basal 0.6 to apex. Tho- segment; claws strongly curved, apical rax: Pronotum (Fig. 2) subhexagonal, 2/5 almost perpendicular to base. Abdo- broad, c. 1.3X width of head at eyes, men: Sternum VII (5th visible) with 770 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON posterior margin broadly, shallowly Examined) and Rio de Janeiro (Denier emarginate; sternum VIII moderately 1940). — emarginate (Fig. 5). Tergum IX consist- Hosts. Larvae associated with Mono- ing of a pair of well-developed, setose, eca haemorrhoidalis (Apidae); adult host lateral tergites; sternum IX (spiculum plants unknown. gastrale) (Fig. 6) Y-shaped, with a very short base, c. 0.7X as long as gonofor- Discussion ceps (Figs. 7-8). Gonostyli c. 1.7X The examination of recently collected length of gonocoxal piece, divided in material as well as the holotype of apical 1/2, fused medially with gonocoxal Tetraolytta gerardi supports transfer of piece, each gonostylus narrow, sinuate in this enigmatic species to the Tetraonyci- outline, inflated immediately below apex nae. Earlier placement in Meloinae was (Fig. 7). Aedeagus (Fig. 9) 0.8X length prompted by phenetic similarity to South of gonoforceps, with a single, relatively American lyttine genera, i.e., Megalytta small dorsal hook apically, and a robust Selander. However the bilobed tarsal and pointed ventral endophallic hook. segments and fusion of the gonostyli Female. Non-genitalic features as in with the gonocoxal piece in males alone male except antennal segments III-XI are two tetraonycine synapomorphies more robust (Fig. 1), less elongate; separating Tetraolytta from all Meloi- length/width of segments I XI: 2.0, 0.6, nae. 1.3, 1.3, 1.4, 1.6, 1.7, 1.8, 1.8, 1.7, 3.0; XI Among the four genera of Tetraony- only c. 1.5X length of I. Sternum VII cinae, Tetraolytta is most easily separat- (5th visible) not noticeably emarginate ed from Meloetyphlus and Opiorneloe. posteriorly; sternum VIII only slightly The latter two are characterized by emarginate. Tergum IX as in males. Selander (1965, 1985). Wing and eye Gonocoxites stout, relatively short, structure is distinct in these taxa. Meloe- shorter than styli, gonostyli c. 5X as typhlus lacks eyes, and has strongly long as wide, curving slightly toward abbreviated elytra and vestigial hind midline and —widening slightly to apex. wings (Selander 1965). In Opiorneloe Variation. Minor variation between compound eyes are present but are holotype and other specimens as follows: relatively small and clearly separated (a) gula, maxillae, labium and postocci- from the base of the mandibles, and its put orange brown in type; these areas hind wings are abbreviated, narrow, with darker brown in other specimens; (b) reduced venation and unfolded (Selander color of prosternum, mesopleura and 1985). Tetraolytta is most similar to forecoxae orange brown in type; these Tetraonyx. Characters separating Tetra- areas vary from orange brown to brown olytta from the vast majority of Tetra- in more recently collected material; onyx include those that provide Tetra- (c) head punctation fme and sparse in olytta its phenetic similarity to lycid type, whereas finely but densely punctu- beetles, specifically the more elongate, ate in other specimens; (d) in the type the narrower body form, the longer and pronotal setae are yellow and sparse heavier antennae with well-separated on the black area at middle of disk; segments, and the more planate and these setae are black in the other speci- posteriorly expanded elytra. This con- mens. The latter difference may be trasts with most Tetraonyx species which attributable to fading over time in the are robust beetles with considerably type. — shorter often subclavate antennae with Geographic distribution. Southern closely appressed segments, and convex, Brazil; states of Parana (see Material posteriorly tapering elytra. Other distinct VOLUME NUMBER 109, 4 771 differences in Tetraolytta, include the of the pronotal disk are not rounded at considerably longer and apically nar- its apical third. Yet, T lycoides at least, rowed antennal segment XI, the smooth has certain interesting similarities to T. frontal bulla on the head, and the gerardi. In both species the antennae are apically rounded lateral margins of the decidedly atypical of Tetraonyx; they are pronotal disk. longer, heavier, narrowing somewhat When discussing the possible tetraony- toward the apex, and in T. lycoides, cine affinity of Tetraolytta gerardi, Pinto subserrate. Also segment XI, although and Bologna (1999) suggested a relation- longer in T. gerardi, is abruptly nar- ship to Tetraonyx distincticollis Pic 1916, rowed distally in both species. Head and a Brazilian species constituting the mono- pronotal structure suggest that these typic subgenus Paratetraonyx Kaszab, similarities are convergent. General anat- 1958. This purported relationship was omy associates T. lycoides with Haag- based on comparisons from the literature. Rutenberg's (1879) group A, whereas Upon examination of specimens of T. Tetraolytta is phenetically more similar distincticoUis, including the type (Muse- to his group C. um National d'Histoire Naturelle), we Tetraolytta is inadequately separated find little in common with T. gerardi. The from Tetraonyx at present. Only color only noteworthy similarity is the elongate pattern combined with the cephalic first tarsomere of the middle and hind bulla, relatively narrow tempora, and legs. In both species tarsomere I of the anteriorly rounded pronotal disk mar- hind leg is subequal to half the entire gins will separate it from all Tetraonyx tarsal length. This segment generally is species known to us. Consequently, considerably shorter in Tetraonyx. Al- Tetraolytta may eventually be shown to though likely to be a derived feature, the be a derived lineage of Tetraonyx and lack of correspondence in other traits that genus recognition renders the latter suggests convergence. Interestingly, both paraphyletic. We are not aware of any species have been collected together, derived features of Tetraonyx that dif- parasitizing the same species of bee (L. ferentiate it from the other tetraonycine Correia da Rocha Filho and J. Rozen, genera. Because Tetraonyxis such a large personal communication.). and poorly known genus it is impossible Of greater interest are the two Tetra- at present to provide a strong argument onyx species T. superbus Pic 1915 and T. for or against generic separation of lycoides Selander and Martinez, 1984, Tetraolytta. The same can be said for also assumed to be lycid mimics. In these recognition of Meloetyphlus and Opio- species, as in Tetraolytta gerardi, the meloe, the two other tetraonycine genera elytra are flared posteriorly which pro- which may also be derived from Tetra- vides much of the lycid phenotype. onyx (see Selander 1985). Pending a bet- Unfortunately both are known from ter understanding of Tetraonyx diversity single female specimens which we have and a phylogenetic analysis of the sub- not studied. Both species are separated family we continue to tentatively recog- from T. gerardi by color pattern, prono- nize all four genera as distinct. tal dimensions and size, and antennal Acknowledgments structure. Unlike T. gerardi, both Tetra- onyx have yellow markings on the legs We thank Claude Girard, Museum and head. Furthermore, in T. superbus National d'Histoire Naturelle, for exam- the elytra are costate; and in T. lycoides ination of the Pic Collection, and Otto the head is divergent above the eyes and Merkl, Hungarian Natural History Mu- widest at the tempora, and the margins seum, for examination of the Kaszab 772 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON Collection. We also are grateful to Jerry Kaszab, Z. 1959. Phylogenetische Beziehungen des Rozen (American Museum of Natural Fliigelgeaders Meloiden (Coleoptera), nebst History, New York) for the gift of speci- ABcestcahrZeoiobluonggicaneAuceardeGmaitateunSgceinentuinardumArHtuenn-. mens ofTetraonyxdistincticoUisaswell as garicae 5: 67-114. to Leo Correia da Rocha Filho (Uni- MacSwain, J. W. 1956. A classification ofthe first versidade Federal do Parana, Curitiba) instar larvae of the Meloidae (Coleoptera). for the recently collected specimens of University ofCalifornia Publications in Ento- Tetraolytta gerardi and host information. mology 12: 1-182. Pic, M. 1919. Coleopteres exotiques en partie Marta Bologna and Andrea Di Giulio nouveaux. L'Echange 35(391): 2-3. helped with the arrangement offigures. Pinto, J. D. and M. A. Bologna. 1999. The New World Genera of Meloidae (Coleoptera): A Literature Cited key and synopsis. Journal of Natural History Bologna, M. A. andJ. D. Pinto. 2001. Phylogenetic 33: 569-619. studies ofMeloidae (Coleoptera), with empha- Selander, R. B. 1965. The systematic position of sis on the evolution of phoresy. Systematic Meloetyphlus, a genus of blind blister beetles Entomology 26: 33-72. (Coleoptera: Meloidae). Journal ofthe Kansas Denier, P. 1933a. Documentos para la classifica- Entomological Society 38: 45-55. cion de los Meloidos Americanos. Boletin . 1983. An annotated catalogue of blister Menusel del Ministerio de Agricultura de la beetles of the tribe Tetraonycini (Coleoptera, Nacion 32: 35-52. Meloidae). Transactions of the American . 1933b. Contibucion al estudio de los Entomological Society 109: 277-293. Meloidos Americanos. Revista Chilena de . 1985. Anewgenusofblisterbeetles linking Historia natural 37: 237-246. Meloetyphlus with Tetraonyx (Coleoptera: . 1935. Coleopterorum Americanorum fa- Meloidae). Journal ofthe Kansas Entomolog- miliae Meloidarum enumeration synonymica. ical Society 58: 611-619. Revista de la Sociedad Entomologica Argen- Selander, R. B. and A. Martinez. 1984. A synopsis tina 6: 139-176. of the genus Tetraonyx in Argentina (Co- . 1940. Description de Lytta neivai, n. sp., leoptera: Meloidae). Proceedings of the Ento- du Bresil et notes sur quelques Lytta F. de mological Society ofWashington 86: 913-929. TAmerique du Sud (Col., Meloidae). Revista Selander, R. B. and T. C. Selander. 1992. A new de Entomologia 11: 799-802. species and new records of Tetraonyx from Haag-Rutenberg, J. G. 1879. Beitrage zur Kennt- Argentina (Coleoptera, Meloidae). Journal of niss der Canthariden. I. Tetraonyx. Stettiner the Kansas Entomological Society 65: EntomologischeZeitung40: 249-275, 287-314. 357-368.

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