Phylogenetic relationships among the species of Panthiades hübner (Lycaenidae: Theclinae: Eumaeini)

2005·3.7 MB·

by  Robert K Robbins

PROC. ENTOMOL. SOC. WASH.
107(3). 2005, pp. 501-509
PHYLOGENETIC RELATIONSHIPS AMONG THE SPECIES OF PANTHIADES
HUBNER (LYCAENIDAE: THECLINAE: EUMAEINI)
Robert K. Robbins
Department of Entomology, RO. Box 37012, NHB Stop 127. Smithsonian Institution,
DC
Washington, 20013-7012, U.S.A. (e-mail: [email protected])
—
Abstract. A species level phylogenetic analysis ofPanthiades Hiibner was performed
using twelve characters of wing pattern, androconia, and male and female genitalia. The
purposes were to determine whether Panthiades is monophyletic without Cycnus Hiibner
and to provide a cladogram for a project on the evolution of "false head" wing patterns.
Parsimony analysis with all characters unordered yielded two trees. One was the strict
consensus of the two trees, and the other was the only most parsimonious tree when one
ofthe multi-state characters was ordered. Panthiades is characterized by five hypothesized
synapomorphies. If Cycnus is recognized, Panthiades is not monophyletic on either of
the most parsimonious cladograms. The "classic" false head wing patterns in Panthiades
appear to have evolved once.
Key Words: hairstreaks, false head hypothesis, Cycnus
Nicolay's (1976) taxonomic treatment of unclear whether the classic "false head"
Panthiades Hiibner and Cycnus Hiibner has wing pattern evolved once or twice in the
been stable with minor exceptions. Robbins Panthiades!Cycnus lineage, especially since
(2004a, b) changed two specific epithets for Nicolay (1976) placed one in Cycnus and
nomenclatural reasons and synonymized one in Panthiades.
the monotypic Cycnus with Panthiades, In this paper, I infer phylogenetic rela-
stating that Panthiades was probably not tions among the eight species ofPanthiades
monophyletic without Cycnus. Consistent for the purposes of assessing the monophy-
with this synonymy, Nicolay (1976:3) had ly of Panthiades without Cycnus and of
noted that "the entry of the ductus semin- providing a cladogram for ongoing studies
alis on the ventral-lateral side ofthe corpus ofthe evolution of wing patterns associated
bursae" is shared by Panthiades and Cyc- with the "false head" hypothesis.
nus, but not by other close relatives.
Materials and Methods
Panthiades is of biological interest be-
cause it contains two species, P. bathildis Coded characters were derived from a
(Reakirt) and P. phaleros (L.), that have comparison of adult morphology using
wing patterns (Fig. 10) traditionally asso- 1,009 pinned specimens of Panthiades in
ciated with the "false head" hypothesis of the National Museum of Natural History,
predator avoidance (Robbins 1980). These Smithsonian Institution, Washington, DC,
wing patterns show a significantly greater USA. plus numerous specimens borrowed
incidence of unsuccessful predator attacks from other museums. In addition, 41 geni-
directed to the "false head" than other ly- talic dissections of both sexes of the eight
caenid wing patterns (Robbins 1981). It is Panthiades species were examined. Pan-
502 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Table L Character matrix lor I'diithiiulcs. The outj^roups are the type species of Parrhasius, Thepytus, and
Porthecld. Characters and their states are detailed in the text.
Cliaractcrs
)
VOLUME NUMBER
107, 3 503
has one state in Panthiades and a second 4). It is unclear whether these scales form
state in all other Panthiades Section genera, a scent patch, but I tentatively treat them as
so it does not affect the inferred phyloge- androconia because they are restricted to
netic relations within the genus. males. They occur in three species of Pan-
Character 1: Ventral hindwing postme- thiades, one Thepytus, and two Parrhasius
dian line segment in cell Sc+Rl-Rs (0) co- (Nicolay 1979). The size and shape of the
linear with remainder of postmedian line, black scales often varies geographically, at
(1) basally displaced. In three Panthiades least in Panthiades and Parrhasius (Nico-
species, the postmedian line is not recog- lay 1976, 1979). There is a patch of dark
nizable, so these species were coded with a brown scales in P. aeolus between the scent
question mark. pads on the disco-cellular veins and at the
Dorsal wing pattern.-C/zarac?er 2: Dor- base ofvein M3 (Fig. 3, arrow B) thatcould
sal wings of female with (0) shining blue- possibly be homologous with the black
green iridescence, (1) a varying amount of scales, for which reason I code the second
dull, "chalky" blue scales. The second character below with a question mark forP.
character state is restricted in Panthiades to aeolus.
P. bathildis and P. phaleros, where it varies Character 3: Scent pad in the discal cell
within each species from no blue to a dull surrounded by a ring ofscales that are tight-
blue sheen that is distinguishable from the ly attached to the Wing membrane (0) ab-
shining iridescent blue-green of the other
sent (Fig. 3), (1) present (Fig. 4).
species. — Character 4: Black scent patch distal of
Androconia. Androconia in Panthiades
the discal cell (0) absent, (1) present (Fig.
are restricted to the dorsal forewing and are
composed ofthree parts. The first is a black 4, Mleatlteer Bg)e.nitalia.—As noted by Nicolay
(rarely gray or tan) scent pad in the discal
(1976), the genitalia ofPanthiades are more
cell surrounded by a conspicuous ring of
interspecifically variable than those of
scales (Figs. 1-2, also fig. 122 in Eliot many other eumaeine genera. Five charac-
1973), which are usually gray in color.
ters are coded.
These androconia and the surrounding ring
Character5: Number ofcornuti in penis
of scales are tightly attached to the wing
membrane. They occur in all Panthiades (0) 1, (1) 2. Cornuti are usually easily
scored in eumaeines, including Panthiades.
except P. aeolus (Fig. 3), but nowhere else
However, outgroup genera Parrhasius and
in the Eumaeini.
The second part is a gray to dark char- Porthecla are problematic in that the folded
vesica within the penis has patches of vary-
coal colored scent pad that is universal in
the Panthiades Section. It is distal of the ing sclerotization, making it difficult to de-
ring of scales (Figs. 1-2, 4) and is, in turn, termine what is and is not a cornutus. De-
composed of two parts. The first is very spite this problem in Parrhasius and Por-
roughly oval and usually covers the upper thecla, for which reason they are coded
and middle disco-cellular veins and parts of with question marks, the two states within
the wings basal and distal of these veins Panthiades are clear.
(Fig. 2). There is sometimes a second part Character 6: Gnathos tips (0) flared. ( 1
at the base of vein M3 (most conspicuous not flared. Modification of the gnathos is
in P. aeolus. Fig. 3, arrow C), but its pres- unusual in the Panthiades Section, and the
ence is intraspecifically variable in some first state was illustrated by Nicolay ( 1976).
species, such as P. bitias, for which reason The gnathos of P. aeolus have a laminate
it is not coded. carina (sensu Field 1967) at the elbow, but
The third part is a patch of black scales, it is the only species in the Panthiades Sec-
usually on the distal half of the wings (Fig. tion with such a clearly developed carina
504 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Figs. 1-4. Dorsal forewing androconia. 1, Panthiadesphaleros, arrow A points to ring ofscales around one
scent pad (Character 3), arrow B to second scent pad distal ofring ofscales. 2, P. phaleros wing slide showing
scent pads in relation to wing veins, arrows A and B as in previous figure. 3, P. aeolus, arrow A points to scent
pad covering the upper disco-cellular veins, arrow B points to dark scales that may be androconia, arrow C to
scent pad at base of vein M3. 4, P. ochus, letter B is in middle of dark scales that may be androconia (Char-
acter4).
on the elbow, for which reason it was not aspect (0) roughly triangular, but more than
coded. twice as long as wide (Fig. 5), (1) duplex
Character 7: Ventral surface of valvae with a well-developed internal ridge de-
fused anteriorly (0) 0-30% of length, (1) marcating the two parts (Fig. 6), (2) roughly
30-50% of length, (2) 50-70% of length, an equilateral triangle (Fig. 7). Because the
(3) 70-100% oflength. Nicolay (1976) first valva of outgroup P. polibetes is so differ-
reported the fused valvae in Panthiades ent in shape from that in Panthiades (cf. fig.
(Figs. 5-7). 2 in Nicolay 1979), it is coded with a ques-
Character 8: Shape of valva in ventral tion mark.
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107, 3 505
Figs. 5-7. Male genitalia saccus and valvae in ventral aspect (anterior is down, digitized from Nicolay
1976). 5, Panthiades aeolus, each valva is longer than wide. 6, P. phaleros, each valva is duplex, separated by
a well-developed internal ridge (arrow). 7, P. boreas, each valva is roughly an equilateral triangle.
Character 9: Ventral of the notch where Female genitalia. Character 10: Signa
the labides meet, the length ofthe presumed (0) skillet-shaped (Fig. 8), (1) rectangular
remnant uncus is (0) <0.05mm, (1) and narrow (fig. 22 in Nicolay 1976), (2)
—0.1mm. So far as I am aware, the second with a single central spine (fig. 3 in Nicolay
character state only occurs in Panthiades 1979). The skillet-shaped signa (Fig. 8, ter-
and Thepytus. minology from Nicolay 1976) occurs only
Fig. 8. Female genitalia (bursa copulatrix) ofPanthiades boreas in lateral (left) and ventral (right) aspects.
Scale 1 mm.
PROCEEDINGS OFTHE ENTOMOLOGICAL SOCIETY OF WASHINGTON
506
epytus
4
9 polibetes
porthira
aedus
[59]
[95]
2 7 8 bathikfs
1 7 10 11 12
10
1 2 1
^phaleros
10
[65]
[59]
5
-•—
3 7 8
1 3 2 hebraeus
boreas
[74]
4 6
M>4-
ochus
paphlagon
Fig. 9. One oftwo most parsimonious cladograms (character 7 unordered, 17 steps, CI = 0.94, RI = 0.96)
for Paiuhiades species. Thepytus epytus. Parrhasiuspolibetes. and Portheclaporthura are tiie outgroups. Char-
acternumbers are placed above nodes and character state numbers below nodes. Open circles representreversal
orconvergence ofthe character state at that node. Jackknife support is noted in brackets above each node. This
cladogram is also the consensus ofthe two most parsimonious trees.
VOLUME 107, NUMBER 3 507
Fig 10 Most parsimonious cladogram (character 7 ordered, 17 steps, CI = 0.94. RI = 0.96) lor Panthuules
species. Thepytus epytus. Parrhasius polihetes, and Porthecla porihura are the outgroups. Character numbers
are placed above nodes andcharacterstate numbers below nodes. Opencircles represent reversal orconvergence
ofthe character state at that node. This cladogram is also one ofthe most parsimonious trees when character 7
wisinugnorpadtetreerdn.sTinheP.vbeantthrialldiwsinangdpPa.ttpehranloefroesacahppesapercitoeshaisvepleavcoeldveodnotnhceecilnatdhoegirraimm.meTdhieatcelascsoicmm"otanlsaencheestaodr.
508 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
in Panthiades, and the rectangular and nar- shaped, and (5) ductus seminahs arises on
row signa occurs in P. phaleros (fig. 23 in the left ventral side of the corpus bursae.
Nicolay 1976). Except for the first, these characters had
Character 11: Lamella postvaginalis in been explicitly noted by Nicolay (1976). If
ventral aspect (0) sclerotized and fan- P. phaleros is moved from Panthiades to
shaped (Fig. 8), (1) not fan-shaped (Fig. 3 Cycnus, then Panthiades is not monophy-
in Nicolay 1979). The first state occurs in letic on either of the most parsimonious
Panthiades and not the other genera of the trees (Figs. 9, 10), whether character 7 is
Panthiades Section. ordered or unordered. These results support
Character 12: Origin of ductus semin- the classification in Robbins (2004b).
alis (0) on the left ventral side ofthe corpus Panthiades bathildis and P. phaleros
bursae (Fig. 8), (1) on the dorsal side ofthe have wing patterns that have traditionally
corpus bursae. In the Panthiades Section, been associated with the "false head" hy-
the origin is usually on the left side, but in pothesis (Robbins 1980, 1981). The phy-
Parrhasius, it is very close to the center. logenetic results suggest that this wing pat-
tern evolved in the ancestor ofthe two spe-
Phylogenetic Analyses and Results
cies (Fig. 10). In Nicolay's (1976) classifi-
I analyzed the coded data (Table 1) using cation, this result was not evident.
the Hennig86 "ie*" option, which searches
exhaustively for the most parsimonious Acknowledgments
cladograms. The analysis with character 7 I am grateful to Stan Nicolay for more
unordered yielded two equally parsimoni- than I can everreasonably acknowledge, es-
ous 17-step trees with a consistency index pecially sharing for three decades his broad
of 0.94 and retention index of 0.96. The knowledge of the Neotropics and its eu-
first (Fig. 9) is also the strict consensus tree. maeine fauna. Specifically for this paper, he
The second (Fig. 10) is the only most par- allowed me to scan digitally his genitalia
simonious tree when character 7 is treated drawings. For drawing the female genitalia
as ordered. Successive weighting did not of P. boreas, I thank Vichai Malikul. For
change the cladogram topology. Jackknife making suggestions on the manuscript, I
support values are reported for the consen- thank Marcelo Duarte, Gerardo Lamas, Tia-
sus tree (Fig. 9) and were slightly lower go Quental, John Shuey, and Andy Warren.
than those for the other most parsimonious
tree with character 7 ordered. In both ofthe Literature Cited
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