Two new species of the strigatus species complex of the ant genus Cyphomyrmex (Hymenoptera: Formicidae) from Costa Rica and Panamá

2010·4.8 MB·English

by  William P Mackay

HYM. RES.
J.
Vol. 19(1), 2010, pp. 44-50
Two New Species of the strigatus Species Complex of the Ant Genus
Cyphontyrmex (Hymenoptera: Formicidae) from Costa Rica and Panama
William P. Mackay and Francisco Serna
DepartmentofBiologicalSciences,CentennialMuseum,TheUniversityofTexas,ElPaso,TX79968,
USA and Grupo Sistematica de Insectos Agronomia SIA, Museo Entomologico UNAB,
Carrera 30 #45-03, Universidad Nacional de Colombia, Bogota, COLOMBIA
[email protected]; [email protected]
—
Abstract. ThestrigatusspeciescomplexisdefinedasthoseworkersandfemalesofCyphomyrmex
in which the preocular carina extends back to the vertex, delimiting the lateral margin of a
depressedconcavescrobe. Themandibleshave6ormoreteethandthereisasinglemedialpronotal
tubercle. The complex was previously reported only in South America, especially southeastern
BrasilandnorthernArgentina. TwonewspecieswerefoundinCentralAmerica: C. andersonifrom
CostaRica,and C.snellingifromPanama. CyphomyrmexandersoniresemblesC. quehradae,butcanbe
separated as the hind femur is longer than the head capsule (shorter in C. quehradae). It can be
differentiated from the similar C. hruchi as the mesosomal tubercles are distinct (indistinct in C.
bruchi). Cyphomyrmex snellingi has the frontovertexal corners lobate and somewhat projecting
posteriad. Itismostsimilarto C.faunulus,butcanbeeasilydistinguished as theanteriormesonotal
tubercleisnotmoredevelopedthantheothertubercles (muchlargerthantheothersinC.faunulus).
—
Resumen. El complejo strigatus del genero Cyphomyrmex se caracteriza porque las hembras y
obreraspresentanunacarinapreocularque seextiendeposteriormentehasta elvertexydelimitala
margenlateraldeunescroboantenal deprimidoyconcavo. Estashormigasposeenmandibulascon
6 o mas dientes, y un solo tuberculo pronotal mesial. El complejo strigatus se conocia solo de
Suramerica, especialmente el sureste de Brasil y norte de Argentina. Dos nuevas especies fueron
halladas en America Central: C. andersoni de Costa Rica, y C. snellingi de Panama. Cyphomyrmex
andersoni es similar a C. quehradae, pero se diferencia porque el femurposterior es mas largo que la
capsula cefalica (mas corto en C. quehradae). A su vez, C. andersoni puede ser diferenciada de C.
hruchi porque los tuberculos mesosomales son distinguibles (no distinguibles en C. hruchi).
Cyphomyrmex snellingi tiene las esquinas frontovertexales lobosas y algo proyectadas poste-
riormente. Estaespecieesm^as similara C.faunulus,delacualpuedeserdistinguidafacilmentepor
el tuberculo mesonotal anterior no tan desarrollado.
The ant genus Cyphomyrmex belongs to head, which covers most of the head. The
the New World fungus growing ants ofthe mesosoma has a series of pairs of blunt
tribe Attini, and presently contains 40 tubercles in nearly all species. The first
species (Bolton et al. 2007). The genus is opisthogastral tergum* (see glossary in
divided into two species complexes, the Serna and Mackay 2010) lacks tubercles.
strigatus complex (Kempf 1964) and the Most surfaces are dull and without sculp-
rimosus complex (Kempf 1965; Snelling and ture; the hairs are mostly limited to
Longino 1992). Cyphomyrmex workers and appressed, often scale-like setae that are
females are easily recognized, as the frontal nearly always restricted to the gaster and
carinae form a shield on the dorsum of the the head.
.
Volume 19, Number 1, 2010 45
Most species nest in the soil, in rotten METHODS AND MATERIALS
logs and stumps, or in hollow dead twigs. The specimens were examined with a
This genus also nests under bark, under Zeiss stereoscope, at 64X, and were mea-
moss, and within epiphytic pseudobulbs sured with an ocular micrometer. The
(Snelling and Longino 1992). Colonies are abbreviations are as follows:
small, probably not exceeding 500 workers
(Snelling and Longino 1992). All Cypho- HL Head length, measured in full
myrmex species cultivate badisiomycete frontal view, from anterior
fungi in the tribe Leucocoprineae. In the margin of medial lobe of cly-
C. rimosus group, these fungi grow in a peus to medial posterior mar-
yeast form (small masses of unicellular gin of frons
HW
fungal cells) ratherthaninthemulticellular Head width, measured in full
mycelialformtypical for allother attine ant frontal view, maximum width
gardens (Schultz et al. 2002; Schultz and excluding eyes (Measured near
Brady 2008). posterior point of head)
Workers of the strigatus complex can be SL Scape length, excluding con-
recognized by the closed antennal scrobe dyle
(sometimes with poorly defined margins), EL Eye length, maximumdiameter
mandibles with six or more teeth, and with of eye
a single medial pronotal tubercle (appar- EW Eye width, maximum width of
entlyafusionoftwotubercles). The species eye, perpendicular to EL
WL
of the strigatus complex were previously Weber's length, a diagonal line
considered to be primarily southern South from the top of the anterior
American in distribution, although C. edge of the pronotum to the
faunulus occurs as far north as Vene- posterior edge of the pos-
zuela (Mayhe Nunes and Jaffe 1998). teropropodeal lobes.
An unidentified species is found in Co- CI CephaUc index, HW/HL X 100
lombia (Fernandez and Palacio 1995) SI Scape index, SL/HL X 100
and an apparently new species was OI Ocular index, EW/EL X 100
found in Ecuador (Tiputini) by Kari Ryder MCZC Museum of Comparative Zool-
Wilkie (http://people.bu.edu/karitr/genus/ ogy, Harvard University
cyphom3mnex.html) CWEM Collection of William and
In comparison, the workers of the rimo- Emma Mackay, University of
sus complex have an open antennal scrobe Texas at El Paso
(anteriorly), with the preocular carina
curved mesially in front of the eye, and Terms followed by an asterisk are
not directed to the posterior corner of defined at the end of this paper and
the head, the mandibles have five teeth, explained in the glossary of Serna and
Mackay
and the pronotum lacks medial tubercles, (2010).
or has a pair of tubercles. The species of RESULTS
the rimosus complex are widely distribu-
ted from the United States to South Cyphomyrmex andersoni new species
America.
(Figs 1-6)
Two new species of the strigatus species
—
complex were found in Costa Rica and Diagnosis. The worker is a small (total
Panama. These new species wiU be in- length about 2.5 mm, n=2) reddish-brown
cluded in a key to the species of Cypho- ant. The mandibles have six teeth, the
myrmex that can be found at http://www. frontal carinae do not reach the dorsad
utep.edu/leb/antgenera.htm. occular suture, the frontovertexal* corners
46 JournalofHymenoptera Research: Festschrift Honoring Roy Snelling
are barely extended into auricle-like struc- (length 0.04 mm) and rounded; petiole
tures; the pronotum has three angulate enlarged posteriorly, forming dorsal tuber-
processes or teeth, including the medial cles as seen in lateral view (length 0.1 mm,
process and two lateral processes, together height 0.07 mm) that appears to have two
with a pair of posterior swellings, and the lateral tiny bumps; postpetiole with lon-
mesonotum has a pair ofconical processes; gitudinal medial depression flanked by
the propodeum has a pair ofanterior,blunt two longitudinal ridges; all femora swol-
processes and two well-developed angu- len, fore femur with poorly developed lon-
late posterior processes; and the posterior gitudinal carina along posteroventral mar-
1/3 of the petiole is raised into a blunt gin, middle femur similar, but carina
process that appears bidentate when seen poorly developed, posterior femur with
obliquely from above; the postpetiole has well-developed longitudinal carina form-
two parallel raised regions on the dorsal ing distinct angle distad about one third
surface; and the gaster lacks longitudinal length from body.
raised areas. The posterior femur has a Erect hairs absent, except on mandible;
distinctive ventral angulate process, fol- hairs on scape and head appressed, hairs
lowed distally by a poorly defined carina. on ventral surface of head and anterior
The female and male are unknown. margin ofprocoxa subdecumbent, hairs on
—
Distribution. Known only from the mesosoma, petiole, postpetiole, legs and
states of Alajuela and Guanacaste, Costa gaster appressed.
Rica. —
WorHkeWr measurements (mm).—HL 0.76- AlaTjyupeela,se2ri7esk. NHaonldot8ypkeWwowreksetro,fSCoasntRaamRoicna,,
0.78, 0.64-0.66, SL 0.58-0.60, EL 0.13- 29-vi-6-vii-1999, R. Anderson # 19901, 99-109B,
EW WL
0.14, 0.08-0.10 0.90-0.93. Indices: 10°13'30"N; 34°35'30"W (MCZC).
—
CI 84-85, SI 74-79, OI 65-73. Mandible Additional material examined. Costa Rica,
with 6 teeth; anteclypeusbroadly rounded; Guanacaste, Cacao Field Station, 15-ii-1996, R.
paraclypeal teeth* spiniform, moderately Anderson # 1—7682 (1 worker CWEM).
developed; frontal lobes and frontal ca- Etymology. This new species is named
rinae relatively narrow, extending to front- in honor of Robert Anderson, who col-
overtexal corner*, forming carina that fuses lected these specimens as well as thou-
with posterolateral margin of antennal sands of other interesting specimens.
—
scrobe, preocular carina continues poste- Discussion. This specieswould keyto C.
riorly to form mesial margin of antennal olitorForel in Kempf (1964), found in Brazil
scrobe; eyes relatively small, extending and Argentina. Cyphomyrmex undersoni is
HW
past sides of head; scape relatively short, somewhat larger (HL of C. olitor 0.64,
barely reaches frontovertexal comer; pro- 0.56 from Kempf, 1964), has fewer mandib-
notum with medial protuberance, 2 lateral, ular teeth (7-8 in C. olitor), the midpronotal
conical tubercles and 2 posterolateral lo- tubercle is approximately the same size as
bate processes, anteroinfra angle of latero- the lateral tubercles (midpronotal tubercle
pronotum developed; 2 angulate conical much smaller than lateral tubercles in C.
tubercles on mesonotum (height approxi- olitor), and the propodeal spines are well
mately 0.05 mm); anterior margin of developed (poorly developed in C. olitor).
dorsopropodeum with 2 broad processes The mandibular teeth are worn and par-
(height 0.03 mm), dorsopropodeum* rela- tiallyhiddenbythe clypeus in theholotype
mm
tively short (0.08 from notopropodeal andbadlyworninthemandibleoftheother
groove to highest point of anterior tuber- specimen,but this species appears tobe the
cles) posteropropodeum* longer (0.25 mm, only one of the strigatus species complex
measured from anterior tubercles to meta- with six mandibular teeth (and as the
pleural lobe), propodeal spines small members of the rimosus species complex
Volume 19, Number 1, 2010 47
Anterior mesonotal tubercle
Midpronotal Propodeal spine
tubercle
Scape
mm
1
I
Figs 1-6. Cyphomyrmexandersoniholotypeworker: 1,sideview.2,mesosomaasseenfromabove. 3,headand
mandible,frontalviews.4,topofpronotumasseenfromdorsoposteriorview.5,rightposteriorfemurandtibia
posterioraspect. 6, antennal scape.
allhavefivemandibular,itisapparentlythe Cyphomyrmex snellingi new species
onlyspeciesinCyphomyrmexwithsixteeth). (Figs 7-12)
—
Biology. The two specimens were col-
—
lected in montane hardwood leaf litter at Diagnosis. The worker is a small (total
1100-1200 melevation and inwetmontane length 2 mm) ferrugineous red specimen.
forest litter. The mandibles have seven teeth, the spini-
48 Journalof Hymenoptera Research: Festschrift Honoring RoySnelling
form paraclypeal teeth on the clypeus are developed; anterior and posterior mesono-
markedly well developed; the frontal lobes tal tubercles moderately well developed
do not reach the inner borders of the eyes and approximately same size, anterior
(frontal view of head). The frontovertexal tubercle with slighter broader base; dorso-
comers form auricle-like structures; the propodeum shorter that posteropropo-
scape is short, and does not reach the deum, propodeum without spines or an-
posterior margin of the scrobe. The mid gles; subpetiolar tooth sharp and well
pronotal process is angulate, the lateral developed, petiole with two distinct, lon-
pronotal tubercles are poorly developed. gitudinal lateral lobes, dorsum ofposterior
The anterior mesonotal tubercles are con- face extending over anterior part of post-
ical and posterior mesonotal tubercles petiole; postpetiole with longitudinal de-
approximately the same size. The propo- pressed regionindorsumofnode, outlined
deum is rounded posteriorly and without by two elongated elevated areas; dorsal
angles or spines. The subpetiolar tooth is surface of gaster flat, bordered laterally by
well-developed and sharp, dorsally the slightly elevated longitudinal areas; all
petioleextends overthebase ofthe anterior femorawith carinae alongventralposterior
part of the postpetiole, which has two border, that on posterior femur more
longitudinal elevated regions, the poster- developed and forming lamina.
ior margin of the postpetiole is nearly Few erect hairs on mandibles, antecly-
straight; the first opisthogastral* tergum is peus and frontal lobes, remainder of hairs
without ridges or processes; all femora are simple and appressed, located mostly on
swollen ventrally, with carinae, the poster- head and especially gaster.
ior femur has a well-developed ventral All surfaces except mandiblular teeth
lamina. and anterior edge of clypeus dull.
Erect hairs are sparse, present on the —
Type series. Holotype worker (MCZC), 1
mandibles, apex of the scape, ventral paratype worker (CWEM), Panama, Cerro
surfaces of the legs, ventral and posterior Campana, 950 m, 5-vi-1995, R. Anderson
surfaces of the gaster; appressed hairs are #17833.
—
abundant on the dorsum of the first Etymology. Named in honor of the
opisthogastral tergum. memory of Roy Snelling, recalling a pleas-
All surfaces dull, exceptthe region along ant visit to the Los Angeles County
base of mandibular teeth which is smooth Museum of Natural History in May of
and shiny. 2007 where we spent time with Roy,
—
Distribution. Known only from the type Gordon Snelling, Brian Brown, and Wei-
locality in Pan—ama. ping Xie. —
Description. Worker measurements Discussion. Cyphomyrmexsnellingiwould
(mm): HL 0.71-0.74, HW 0.58, SL 0.48- key to C.faunulus in Kempfs key (1964). It
0.50, EL 0.09-0.10, EW 0.08, WL 0.85-0.86. can be easily distinguished as the anterior
Indices: CI 78-81, SI 64-70, OI 82-86. mesonotal tubercle is relatively small, as
Mandible with 7 teeth; spiniform paracly- compared to the greatly enlarged anterior
peal teeth very well developed (length mesonotal tubercle of C. faunulus (Fig. 13).
0.07 mm), frontal carinae relatively nar- Additionally, the posterodorsal edge of the
rowly spaced, not reaching preocular ca- petiole of C.faunulus does not extend over
rina which forms mesiad margin of scrobe; theanteriorfaceofthepetioleasitdoesinC.
eyes extending past sides of head, with snellingi. Cyphomyrmex faunulus also lacks
about 20 ommatidia; scrobe greatly extend- the erect hairs on the frontal lobes.
ing posteriorly, forming auricle-like struc- Although it would key to C. faunulus, the
tures; scapes not reaching posterior margin twospeciesdonotappeartobemorpholog-
of scrobe; tubercles on pronotum poorly ically similar.
Volume 19, Number 1, 2010 49
Midpronotal
tubercle
Auriculate frontovertexal
corner
Scape
Lannina
^ Preocular
carina
Cyphomyrmex faunulus
Paraclypeal
tooth
Figs 7-12. Cyphomyrmexsnellingiholotypeworker:7,sideview.8,topviewofmesosoma(basedinpartonthe
paratype).9,petioleasseenfromabove,postpetioleasseeninanteriorview. 10,postpetioleasseenfromabove.
11,Head. 12,leftfemurasseenfromposteriorview. Fig. 13,Cyphomyrmexfaunulusmesosoma(ReservaDucke,
nearManaus,Amazonas,Brasil, LACM).
—
Biology. The type series was collected strigatus complex uses only mycelium
in a leaf litter extraction from a wet cultivars and is probably plesiomorphic
montane habitat. and paraphyletic to the rimosus complex
(Schultz et al. 2002).
DISCUSSION
Cyphomyrmex has two centers of species
The genus Cyphomyrmex is divided into richness: the rimosus group at about 10°
two species complexes, the rimosus com- north (Mayhe-Nunes and Jaffe 1998),
plex and the strigatus species complex. The whereas the majority of the species of the
50 Journalof Hymenoptera Research: Festschrift Honoring Roy Snelling
strigatus group is restricted to 20°and 30° LITERATURE CITED
south (Sanhudo et al. 2007). The strigatus
group also lacks species with wide dis- Bolton,B.,G. Alpert,P.Ward,and P.Naskrecki.2007.
Bolton's Catalog ofAnts of the World: 1758-2005.
tributions (Mayhe-Nunes and Jaffe 1998) as Harvard University Press, available on CD.
is found in the rimosus complex. Brandao, C. and A. Mayhe-Nunes. 2001. A new
Apparently no new species of the striga- fungus-growing ant genus, Mycetagroicus gen.
tus group have been described since With the description of three new species and
Kempf's revision (1964), although the comments on the monophyly of the Attini
(Hymenoptera: Formicidae). Sociobiology 38:
recently described C. muelleri shows simi- 639-665.
larities to thestrigatus species complex, and Fernandez, F. and E. Palacio. 1995. Hormigas de
along with C. longiscapus, C. costatus and C. Colombia IV: Nuevos registros de generos y
wheelerimaybe related (Schultz etal. 2002). especies. Caldasia 17: 587-596.
A similar new genus Mycetagroicus, with Kempf,W.W. 1964.ArevisionoftheNeotropicalants
three new species has been recently de- ofthegenusCyphomyrmexMayr. PartI. Groupof
strigatusMayr(Hym. Formicidae). Studia Entomo-
scribed (Brandao and Mayhe-Nunes 2001). logica 7: 1^4.
GLOSSARY . 1965. A revision of the Neotropical fungus-
growing ants of the genus Cyphomyrmex Mayr.
Anteclypeus (=''apron''): the anterior Part II: group of rimosus (Spinola) (Hym. For-
portion of the clypeus attached to the micidae). Studia Entomologica 8: 161-200.
Mayhe-Nunes, A. and K. Jaffe. 1998. On thebiogeog-
labrum. Dorsopropodeum: the dorsal sur-
raphy of Attini (Hymenoptera: Formicidae).
face of the propodeum. Ecotropicos 11: 45-54.
Frontovertexal comer: the posterolateral Sanhudo,C, A. Mayhe-Nunes,and C. Brandao. 2007.
angle between frons and vertex. Quern sao as Cyphomyrmex (Myrmicinae: Attini).
Notopropodeal groove: (= "metanotal Biologico 69: 433-434.
groove") a transverse groove on the noto- Schultz, T. and S. Brady. 2008. Major evolution-
ary transitions in ant agriculture. Proceedings
propodeal fusion. of the National Academy of Sciences 105: 5435-
Notopropodeal fusion: In workers, the 5440.
tergal fusion of the thoracic notum and the , S. Solomon, U. Mueller, P. Villesen, J.
propodeum. Boomsma, R. Adams, and B. Norden. 2002.
Opisthogaster (adj. opisthogastral): Cryptic speciation in the fungus-growing ants
Cyphomyrmex longiscapus Weber and Cyphomyr-
(= "gaster") Abd IV to pygidium. mex muelleri Schultz and Solomon, new species
Paraclypeal teeth: (="parafrontal teeth" (Formicidae, Attini). Insectes Sociaux 49: 331-
-Kempf1964, 1965),referringtotheanterior 343.
teeth-like processes on the clypeus. Serna, F. and W. Mackay. 2010. A descriptive
morphology of the ant genus Procryptocerus
ACKNOWLEDGMENTS (Hymenoptera: Formicidae). Journal of Insect
Science (in press).
We would like to thank Roy Snelling and Weiping Snelling, R. R. and J. T. Longino. 1992. Revisionary
XiefortheloanofspecimensofCyphomyrmexfaunulus. notes on the fungus-growing ants of the genus
Two anonymous reviewers provided important com- Cyphomyrmex, rimosus group (Hymenoptera: For-
ments. The research was supported by a grant from micidae:Attini).Pp.479-494in:Quintero,D.,and
the National Geographic Society to Robert Anderson A. Aiello eds. Insects ofPanama and Mesoamerica:
and the Ernst Mayr Fund of the Museum of selected studies. Oxford University Press, Oxford.
Comparative Zoology. 692 pp.