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

2007·4 MB·

by  Marco A Bologna

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.