W. L. Brown, Jr.
The Neotropical Species of the Ant Genus Strumigenys Fr. Smith: Synopsis and Keys to the Species.
Psyche 69:238-267, 1962.

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THE NEOTROPICAL SPECIES OF THE ANT GENUS STRUMIGENYS FR. SMITH : SYNOPSIS AND KEYS TO THE SPECIES1
BY WILLIAM L. BROWN, JR.
Department of Entomology, Cornell University Introduction
The New World Strumigenys have been revised through a series of twelve papers bearing the general foretitle, "The Neotropical species of the ant genus Strumigenys Fr. Smith," plus several articles by Dr. W. W. Kempf and by myself, beginning with my "Preliminary generic revision of the higher Dacetini" (Brown, 1948). It now seems appro- priate to offer 3 unifying synopsis of the New JVorld species of the genus, along with keys for identification and some general remarks. Species Synopsis of New World Strwnigenys .7
1 he synopsis below includes the names, each with author and date of publication, plus citation of the principal references in the Brown or Kempf papers already mentioned, which are listed in the section of "References" at the end of this article. These papers contain refer-
ences to original descriptive and distributional material for each species, but I have included in the synopsis new or supplen~entarl~ information wherever it seemed useful to do so. The species are listed by groups in order of apparent relationship, as closely as it is possible to place them in a purely linear order. The probable relationships within the genus in the New World are discussed at the end of the synopsis. It will be coticed that the group placement of some species differs from that of the previous parts published. The present grouping represents a reconsideration of all of the New World species taken together. Group of ?nundibuZaris
I. Strumigenys mundibularis Fr. Smith, 1860 Brown, 1953b: 53-55, worker, synonymy.
Frederick Smith confused two species under this name; one of these was later described as S. @ros$iciens by Emery. In order to fix these names unambiguously according to present usage, I hereby designate as lectotype of S. mandibuZuris the worker in the British Museum (Natural History), which was called "holotype" in my 1953 paper. 'Published with the aid of a grant from the Grace Griswold Fund of the Department of Entomology, Cornell University. Munuscript receiwed by the editor .iunuury 25,1962.



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19621 Brown - Strumigenys 239
Although this specimen is labeled as "type," Smith never designated a type in print, and at least some of his original specimens exist else- where (eg., in the Munich Museum).
Distribution : Amazon Basin ; known only from the type series. Synonym : S. batesi Forel.
2. Strumigcnys godmani Forel, 1899
Brown, l9S3b : 55-56) worker) female, variation. Biology: Lives in wet forest. The nest I found in Panama was in a small rotten log in cloud forest.
New records: Panama: Progreso, Chiriqui Prov. (F. &I. Gaige leg.) ; Cerro Campana) about 950 m altitude) Panami Prov. (JV. L. Brown, Jr. leg.).
Distribution : Costa Rica) Panama, British Guiana. Synonym : S. ferox Weber.
I
i
3. Sfrumigenys planeti Brown, 1953
Brown, 1953b: 57-59, worker, female, variation) distribution. Biology: Apparently a rain forest species. Weber (1952) reports a nest taken in a wet mossy log in a cacao plantation on Trinidad. New record : Peru : Monson Valley, Tingo Maria, winged female. (E. I. Schlinger and E. S. Ross leg.) .
Distribution : Trinidad, Amazon Basin to Bolivia and Peru. 4.
Strumigenys smithii Forel, I 886
Brown) 1953c: 104-107, worker, variation, distribution, biology. Biology: Nests in rotten logs, rotten twigs or, on St. Vincent) sare- ly in sod. Primarily a forest species.
New records: Colombia: Loma Larga, Sierra Santa Marta (F. M. Gaige leg.).
Panama : Cerro Campana, 800 ni, Province of Panam; (G. I3. Fairchild and W. L. Brown) Jr. leg.). Distribution: Costa Rica south to Santa Catasina, Brazil, atld Amazonian Bolivia; St. Vincent) B. W. I. Synonym : S. smithi var. inaequdis Emery. 5.
Strumigen~s hemdisca Brown) 1953 (Fig. 22) Brown, 1953c: 107-108, worker.
Biology: The type series came from orchid plants intercepted in U. S. plant quarantine, and so were probably nesting amid the epiphy- tes in trees.
Distribution : Venezuela; known only from the type series, 6.
Strumigenys prospiciens Emery, I 906
Brown, 1953c: 108-110, worker, female) distribution,



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240 Psyche
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Distribution: Amazon Basin south to Bolivia and to northern Argentina : Misiones.
7,
Strumigenys biolleyi Forel, 1908 (Fig. 28) Browfi, 1953c: 101-104, worker female, variation, distribution. Biology : A forest species, nesting mainly in rotten logs. New records : Ecuador : 10 miles north of Manglar Alto, Guaymas (E. I. Schlinges and E. S. Ross leg.). Panama: Cerro Campa,na, Panadi Prov., 800 m altitude (JV. L. Brown, Ji-. leg.). Distribution: Southern Mexico (Chiapas) south tluough Central America to Ecuador.
Synonyms: S. tridens Weber, S. luctuosa Menozzi. 8.
Strumige~nys saliens Mays, I 887
Brown, 1954b: 55-57, worker, female, distribution, biology. Biology: Nests in rotten logs and branches lying on the floor of foi-est.
Distribution: Southeastern Brazil and northeastern Argentina: Misiones.
Synoriy~ns : 8. saliem var. procera Emery and vai-. angustice$s Forel. ge
Strumigenys borgmeieri Brown, I 954
Brown, 1954b: 57-59, worker.
Distribution : Bi-azil : Pernambuco ; known only from the holotype. I 0. Strunzigenys trinidadensis Wheelel-, I 922 (Figs. I 4, 23 ) Brown, 1954b : 59-62, worker, male, distribution. New record : Esmeralda, Ecuador (J. Foerstei- leg.). Distribution : Tsinidad, northeastern Brazil, Ecuador, Amazonian Bolivia; probably widespread in the interior of South Anlei-ica. I I. Strunzigenys sanctipauli Icempf, 1958 (Fig. 24) Kempf, 1958b : 556-559, figs. 1-4, worker. Distribution: Brazil: Sersa do blar, SZo Paulo State; known only from the holotype.
12. Strunzigenys subZonga Brown, 1958
Brown, 1958a: 221-222, fig. lC, D, worker, female. Distribution : Bolivia : Lower Rio Madidi ; known only from type series.
13. Strumigenys rehi Forel, 1907
Brown, 1958a: 222-223, worker.
Biology: This species was taken from orchid plants arriving at Hamburg, Germany, a circumstance agreeing with the large eyes of the worker to indicate an arboreal habitat,



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19 621 Brown - Strumigenys
Distribution : Amazon Basin ; exact type locality unknown. 14. Strumigenys cordovensis Mayr, 1887 (Figs. 25) 26,27) Brown, 1958a: 218-220, fig. lB, E, F, G, worker, variation, distribution. Disti-ibution : Soutl~ei-n Mexico to Trinidad and the Guianas. I 5. Stru7nigenj1s nzokensis Forel, I 905 Brown, 1958a: 221, raised from variety to provisional species rank. This is a very doubtful form, most likely a synonym of cordovensis- The wl~ereabouts of the type is unknown. The species is not included in the key.
Distribution : La Moka) Venezuela, type locality. I 6. S~runzigenys dolichopatha TVebei-, I 934 Brown, 1958a: 223-224, fig* lA, worker.
Distribut!on:
Bi-itis!] Guiana: Kartabo; known only from the type Group of cultriger
17. Strzmzigenys cultriyer Mayr, 1887 (Fig. 9) Brown, 1957 : 97-99, worker.
New record : Xaxim, Santa Catasina (F. Plaumann leg.). Distribution : Southeastern Brazil.
I 8. Stvumigmys deltisquanza Bi-own, I 957 Brown, 1957: 99-101, fig. la; b, worker. Distribution : Pana~na Canal Zore : Bari-o Colorado Island ; known from types only.
GsouP of tococae
I 9. Stru~~zigenys tococm Wheelel-, I 929 Brown, 1957: 101-102, fig. lc, worker.
Biology : The types were taken from an abundant population inhab- iting the foliar sacs of Tococa formicaria, a tall myrmecophytic shrub, in the outskirts of B~lh.
Fi-om this circumstance and the large size of the eyes) S. tocome is judged to be an asboreal or subarboreal special- ist.
Distribution : Belh, Brazil, at the mouth of the Amazon ; known only from the type seris.
20. Strurnigenys fairchildi Brown, I 961 Brown, 1961 : 60-61, worker.
This species, described from a single worker, is very close to S. tococae, but differs markedly in gastric sculpture and pilosity. It is



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242 Psyche [December
not known whether 8. fuirchildi lives in plant cavities, but it does seem likely that it is a subarboreal forager. Distribution: Panama: Cerro Campana) Panami Province ca. 800 m altitude; known only from the hoIotype. Figure 1. Strumigenys ludia, worker from Veracruz, dorsal full-face view of head showing fringing pilosity only.
Group of Zudia
2 I. Strumigenys Zongispinosa Brown) 1958 Brown, 1958b: 123-126, figs. 1, 2, worker. Biology : Nests in the soil of tropical forest. Distribution : Panama.
22. Strumigenys marginiventris Santschi, 193 I Brown, 1958b: 126-128, fig. 3, worker, female. Biology: Nests in the soil, often in paths or other other openings, in rain forest or plantations, and the workers forage o~er the open grou,nd among leaves or herbs by day as well as night. Common on
Barro Colorado Island.
New records: Palmar, Puntarenas Dept., Costa Rica) in soil of banana p1antation) several collections (E. 0. Wilson leg.). Distribution : Golfo Dolce region of Costa Rica to northern Colom- bia.
23, Strurnigmys Zudia Mann, 1922 (Figs. I) 5) Brown, 1954a: 194-196, worker, female.
Biology: 8. ludk has been investigated at length in the field by



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19621 Brown - Strumigenys 243
Wilson and in the artificial nest by Wilson and Brown, and the details will be published elsewhere. 8. India is a forest species and' usually nests in rotten branches or twigs lying on the forest floor. The food is chiefly entomobryoid Collembola caught alive in the manner usual for the genus.
New records : Mexico : Ridge between Antiguo Morelos and Nue- vo Morelos (E. S. Ross leg.). Pueblo Nuevo, near Tetzonapa, Vera- cruz (E. 0. Wilson leg.). Costa Rica: Abaca Plantation, Bataan (C. H. Batchelder).
Distribution : Southern Mexico to Costa Rica. Synonym : S. ludia subsp. tennis Weber.
Group of hindenburgi
24. Strurnigenys hindenburgi Forel, 191 5 (Fig. 8) Brown, 1961 : 61-64, worker, pseudogyne, distribution. Distribution : Northern Argentina extending into southeastern Bra- zil.
25. Strumigenys lanuginosa Wheeler, I 905 ( Fig. 4) Brown, 1961: 61-63, worker, female, distribution. Distribution: Southern Mexico, Panama; Bahamas, where prob- ably introduced.
26. Strumigenys ogloblini Santschi, 1936 Brown, 1958c: 136-137, fig. lb, worker, female. Distribution: Northern Argentina, probably also in southern Brazil.
Group of elongata
27. Strumigenys precava Brown, I 954 (Fig. 7) Brown, 1954a: 196-200, worker, female.
Biology: I found this species rather common on Barro Colorado Island in the Panama Canal Zone, nesting in red- or chocolate-rotten logs. One nest found was very large, containing several hundred - perhaps a thousand or more - workers. Workers were seen carrying a mycetophilid larva and a termite nymph into this nest as it was being opened, and a captive colony fed on a wide variety of small arthropods, including entomobryoid colIernbolans.
New record :
Panama : Cerro Campana, Panama Province, about 800 m altitude, in a small rotten log in a cloud forest ravine, with winged females, Jan. 16, 1960 (G. B. Fairchild and W. L. Brown, Jr. leg.).




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Figures 2-6. Strunzigenys spp., workers. Figure 2, 8. lacacoca, paratype,
dorsal full-face view of head, showing fringing pilosity only. Figure 3, S. nevermanni, same. Figure 4, S. lanuginosa, same. Figure 5. S. India, Vera- cruz, side view of posterior alitrunk, nodes and anterior part of gaster, Figure 6, S. lacacoca, paratype, same. Roughly to same scale.



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19621 Brown - Strumigenys 245
Distribution : Panama, British Guiana, Amazonian Bolivia ; prob- ably widespread in hylaean South America. 28. Strunzigenys elongata Roger, I 863
Brown, 1954a: 189-192, worker, female, male, variation, synonymy, distribu- tion, biology.
Biology: This species is definitely a collembolan feeder, common in the leaf litter of tropical forest.
It seems to tolerate drier as well as
wet forest types.
New records: Mexico: Pueblo Nuevo and El Palmar, near Tet- zonapa, Veracruz (E. 0. Wilson leg.). Ocosingo Valley, Chiapas (C. and M. Goodnight and L. Stannard leg.).
Distribution : Southern Mexico to Bolivia and southeastern Brazil. Synonyms: S. imitator Mayr, S. elongata subsp. nicaraguensis Weber.
29. Strumigenys consanii Brown, 1954
Brown, l954a : 192-194, worker.
A larger, more robust relative of elongata with smooth and shining postpetiolas disc.
Distribution : Costa Rica : La Palma, near San Jose, I 500 m alti- tude; known only from the type series.
Group of emeryi
30. Strumigenys emeryi Mann, 1922
Brown, 1959a: 97-99, worker, variation, distribution. Distribution : Honduras, southern Mexico. 3 I. Strumigenys boneti Brown, I 959 (Fig. I 2) Brown, 1959a: 103-104, worker.
Distribution : Southern Mexico.
32. Strumigenys nevernza~nni Brown, I 959 (Fig. 3 ) Brown, 1959a : 99-100, worker, female.
Distribution: Costa Rica: Hondura, 1050 m altitude; known only from types.
33. Strumigenys micretes Brown, 1959 (Figs. 13, 19) Brown, 1959a : 100-101, worker. Brown, 196 : 58-60, variation, distribution. As mentioned in the note in couplet 21 of the key (below), this species and S. lacacoca may actually represent different populations of the same species.
Biology : A species of rain forest and cloud forest. 34. Strumigenys lacacoca Brown, 1959 (Fig?. 2,6)



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246 Psyche
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Brown, 1959a: 101-102, worker. Brown, 196: 58-60, worker variation, distri- bution.
Distribution : Central Panama.
Group of silvestrii
35. Strumigenys silvestrn Emery, 1905 (Fig. 18) Brown, 1959c: 25-28, fig. 1, worker, female, synonymy, variation, distribution. Distribution : Northern Argentina, southern Brazil ; also in Cuba and Louisiana, U. S. A., where probably introduced by commerce. Synonym : S. caribbea Weber.
36. Strumigenys carinithorax Borgmeier, 1934 Brown, 1959c: 29-30, worker, female, male. Distribution : Dutch Guiana : vicinity of Paramaribo. 37. Strumigenys schmalzi Emery, 1905
Brown, 1959c: 28-29, worker,
Distribution : Southeastern Brazil.
38. Strumigenys perparva Brown, 1958
Brown, 1958c: 133-135, fig. la, worker, female. Distribution: Trinidad and the Guianas to Sab Paulo; probably interior Brazil.
Group of louisianae
39. Strumige'nys mixta Brown, 1953 (Figs. I 5, 2 I) Brown, 1953a : 4-5, worker.
Biology: One of the two original series was taken in orchid plants at quarantine, so the species may be arboreal or subarboreal. Distribution : Guatemala ; known only from the types (two locali- ties).
40. Strumigenys louisianae Roger, I 863
Brown, 1953a: 2-3, description of synonymous 8. clasmospongia, worker. Brown, 1953d: 28-31, figs. 1 3, worker, variation, synonymy, distribution. Brown, 196 1 : 64-68, geographical variation, synonymy. Biology: The feeding habits of this species have been studied in some detail by Wilson ( 1950, 1954) and by myself. The food con- sists of a variety of small arthropods found in and on the soil cover and caught by the workers with their trap-like jaws. The preferred prey are entomobryoid and symphypleonan Collembola; poduroid collembolans are not taken.
Distribution: Widespread in the Americas from Virginia and Tennessee south at least to the Tucumin area of Argentina; north-



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19621 Brown - Strumigenys 247
ward in Mexico to sheltered canyons and cultivated areas of southern Arizona ; greater Antilles (except Jamaica). Unaccountably absent from certain well-collected areas within this range, such as parts of the Canal Zone, Trinidad and British Guiana, although plentiful in Costa Rica and at least some localities in Colombia. This species tolerates much drier conditions and will live in plantations and other cultivated situations, so perhaps it is found mostly in habitats outside the primary forest in the central parts of its range. Its range and ecological ampli- tude are greater than those of any other New World Strumigenys. Synonyms: S. unidentata Mayr, S. unispinulosa Emery, S. uni- spinulosa var. longicornis Emery, S. fusca Emery, S. louisianae var. obscuriventris Wheeler, S. bruchi Forel, S. infidelis Santschi, S. eggersi par. cubaensis Mann, S. louisianae subspp. laticephala M. R. Smith, soledadensis Weber, guatemalensis Weber, and costaricensis Weber, S. clasmospongia Brown. The long list of synonyms reflects in part the rather extreme variation shown by this species on the South Ameri- can continent. More peripheral populations (North and Central America, West Indies, Argentina) tend to be more uniform both within 2nd among themselves.
41. Strumigenys products Brown, 1953
Brown, 1953a: 3-4, worker.
This species is a larger, long-mandibulate version of S. louisianae. In view of the extensive variation now known for the latter species in South America, it would not be surprising to find that S. producta is just an extreme local variant of S. louisianae. Distribution: Basin of the Rio Beni, Bolivia; known only from the types.
Group of connectens
42. Strumigenys connectens Kempf, 1958 (Fig. I I ) Kempf, 1958a: 59-64, figs. 1-3, worker, variation. Biology: The paratype series was taken in orchid plants in U. S. quarantine, so the species is presumably arboreal. Distribution : The species is known from two localities, both in Colombia.
43. Strumigenys laevipleura Kempf, I 958 Kempf, 1958a: 64-65, figs. 5-7, worker,
Biology: Like S. connectens, this species was also taken from an orchid shipment, and it may therefore be arboreal in habits. Distribution: Known only from the type series from Colombia, apparently from the vicinity of Medellin.



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248 Psyche
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44. Strumigenys xenognatha Kempf, 1958
Kempf, 1958a: 65-66, fig. 4, female.
Biology: The holotype female, a unique, was taken from orchid plants and bears the same data as the S. laevipleura types, from which it differs too widely to be their queen. Perhaps it is a social parasite of S. laevipleura.
Distribution : Colombia.
Group of gundlachi
45. Strunzigenys subedentata Mays, I 887 Brown, 1960: 48-50, figs. 7, 9, worker, female, male, variation, distribution, biology.
Biology: This species nests in small colonies in the soil or soil cover in mesic tropical forest and feeds chiefly on entomobryoid Collembola. Distribution : Southern Mexico south to southeastern Brazil ; Trin- idad ; probably widespread in interior South America. Synonyms : S. tristani Menozzi, S. clavata Weber. Figures 7-8. Strumigenys spp., workers, dorsal full-face view of head. Figure 7, 8. precava from Panama Canal Zone, showing fringing pilosity only.
Figure 8, S. hindenburgi from Tucumin, Argentina. Not to same scale. 46. Strumigenys trieces Brown, I 960
Brown, 1960: 50-51, fig. 8, worker.
Distribution: Costa Rica; known only from the holotype.



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19 621 Brown - Strumigenys 249
47. Strmigenys denticulata Mays, I 887
Brown, 1960: 47-48, fig. 3, worker, female. Biology: Occurs in both primary and second-growth forest, in leaf litter; epiphytes and in termite nests.
Distribution: Trinidad and the Guianas south to southeastern Brazil ; probably occurs widely in interior South America as well. 48. Strumigenys jamaicensis Brown, 1959
Brown, 1959b: 6, worker. Brown, 1960: 45-46, fig. 4, worker. Distribution : Mountains of Jamaica.
49. Strumigenys gundlachi (Roger, 1862)
Brown, 1960: 40-45, figs. 1, 5, worker, female, synonymy, distribution, biology. In addition to the characters cited in the key, it may be mentioned that fully-colored S. gunLdlachi workers and females are usually darker in color (brownish-red to dark brown) than are those of S. eggersi ( ferruginous yellow).
Biology: S. gundlachi feeds chiefly if not entirely on entomobryoid and sminthuroid Collen~bola, which it catches by employing a rela- tively inactive "ambush" type of hunting, but if the prey struggles after being struck, it may be lifted off the ground and stung in! the manner of other Strumigenys. In many parts of the Caribbean coun- tries, this is a very abundant ant in the leaf litter of tropical forest, thickets and plantations, and it tolerates a wide variety of ecological conditions.
Distribution : Central America and southern Mexico, southern Florida, West Indies to Trinidad.
Synonyms: S. eggersi varieties vincentensis Forel, banillensis Sant- schi, isthmica Santschi and berlesei Weber; S. eggersi subsp. infuscara Weber, and S. bierigi Santschi.
50. Strumigenys eggersi Emery, 1890 (Figs. 10, 20) Brown, 1960: 46-47, figs. 2, 6, worker, female, variation, distribution, biology. Biology: Found in forests, thickets, gardens, etc. Almost certainly a collembolan feeder.
Distribution: Trinidad and the Guianas to southeastern Brazil and Amazonian Bolivia. Widespread (possibly by recent introduction) in the West Indies ; southern Florida ; southern Mexico.