Strumigenys gundlachi

AntWiki - Where Ant Biologists Share Their Knowledge
Jump to: navigation, search
Strumigenys gundlachi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. gundlachi
Binomial name
Strumigenys gundlachi
(Roger, 1862)

Pyramica gundlachi casent0103867 profile 1.jpg

Pyramica gundlachi casent0103867 dorsal 1.jpg

Specimen Label

Synonyms

This widespread species is found in leaf litter where it is a predator on smaller arthropods.

Identification

Bolton (2000) - A member of the gundlachi-complex in the Strumigenys gundlachi group. Within the gundlachi-complex, gundlachi has four close relatives: Strumigenys denticulata, Strumigenys eggersi, Strumigenys enopla and Strumigenys jamaicensis. The first three are very widely distributed but the last two are restricted to Colombia and Jamaica respectively. The five species together share the following combination of characters.

1. Mandibles moderate to very long, MI 58 - 85, with inner margins concave to very shallowly convex; the inner margins do not meet at any point except the extreme apex.

2. Between the apicodorsal and apicoventral teeth of the apical fork are 2 minute intercalary denticles that arise in the space between the teeth, not from the ventral surface of the upper tooth.

3. Preapical dentition consists of 4 - 12 denticles or small teeth. The pair of labral trigger hairs are long and very often are adherent or twisted together, at least in preserved material, so that distal of the extreme base only a single hair may appear to be present.

4. Main pilosity: leading edge of scape with curved hairs that are narrowly spatulate and relatively fine. Apicoscrobal and pronotal humeral hairs present, often sub flagellate to flagellate, or looped ; sometimes these hairs may be filiform or elongate and narrowly remiform. The cephalic dorsum has 2 pairs of standing hairs: one close to highest point of vertex , the other close to the occipital margin. A single pair of erect hairs occurs on the mesonotum.

5. Postpetiole is always densely reticulate-punctate.

Of the 5 species denticulata and eggersi have postpetiolar spongiform lobes that are at best extremely reduced and usually completely absent. P. denticulata has relatively very long mandibles (MI 72 - 85 as opposed to MI 58 - 65 in eggersi). The first gastral tergite of eggersi is always distinctly reticulate to reticulate-punctate whereas in denticulata the tergite is at most superficially reticulate near the base. In gundlachi and jamaicensis the postpetiolar spongiform lobes are distinct, though they may be small in the former. P. gundlachi is widely distributed, dull yellow to yellowish-brown in colour and has tiny mandibular preapical denticles and a small ventral postpetiolar lobe. P. jamaicensis is restricted to Jamaica, is blackish brown to black in colour, has strongly developed and very conspicuous preapical mandibular denticles, and a large ventral postpetiolar lobe. P. enopla, which appears to be restricted to Colombia, falls between these two pairs as its ventral postpetiolar lobe, whilst present, tends to be small or very small. It is a darkly coloured species (blackish-brown to black) with long scapes, and its mesonotum always bears a pair of long straggly flagellate hairs.

P. gundlachi, together with eggersi, are the only species of this group to have been recorded from the U.S.A., where they are apparently restricted to Florida (Brown, 1960a; D. R. Smith, 1979; Deyrup, Johnson, et al., 1989).

Longino (Ants of Costa Rica) - Mandibles in full-face view linear, elongate and narrow; leading edge of scape with freely projecting hairs; inner margin of mandible without a tooth or distinctly enlarged denticle at or near the midlength; labral lobes short, trigger hairs at apices of lobes long; mandibles straight, with weakly convex inner borders, each bearing 4-9 minute denticles on distal 1/2; spongiform appendages present on ventral surface of petiole and postpetiole (in constrast to eggersi); first gastral tergum smooth and shining (in constrast to eggersi).

Keys including this Species

Distribution

This species has been introduced into Florida, where it is an uncommon species in mesic woods and gardens in Dade, Monroe, and Collier counties. Pest status: none. First published Florida record: Brown 1960. (Deyrup, Davis & Cover, 2000.)

Distribution based on Regional Taxon Lists

Nearctic Region: United States.
Neotropical Region: Bahamas, Colombia, Costa Rica, Cuba (type locality), Dominican Republic, Ecuador, Greater Antilles, Guatemala, Honduras, Jamaica, Lesser Antilles, Mexico, Nicaragua, Panama, Peru, Puerto Rico, St. Vincent, Trinidad and Tobago, Venezuela.

Distribution based on AntMaps

AntMapLegend.png

Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Brown (1960) - E. O. Wilson (unpubl. notes) kept a colony of gundlachi for over a month in Cuba, during which time it captured and consumed entomobryoid and sminthurid collembolans, but ignored poduroids, a small cricket nymph, various mites and minute millipeds. Hunting is usually of the relatively immobile ambush type, which is to say that the ants approach the prey and, when close enough to detect its position, freeze with mandibles held open toward it (at an angle of 60-70 degrees in this case). However, sometimes workers approach the prey and strike quickly and directly, without waiting. If prey is struck and continues to struggle, it is lifted off the ground and stung in the usual manner of Strumigenys.

McCluskey and I found this species in nearly every berlesate of upper soil and leaf litter that we examined on Barro Colorado. Island; it is evidently there the most common dacetine species and one of the more frequent ant species of the forest floor. Wilson found gundlachi to be somewhat less abundant in Veracruz. Although it is abundant in tropical rain forest, it also lives in second-growth forest, thickets, and cacao plantations. Weber (I952) took a sample deep in a cave on Trinidad among manure and debris from the oil-birds (Steatornis) and bats living there.

Brown (1962) - In many parts of the Caribbean countries, 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.

Deyrup (1997) - This species seems to require habitats that are slightly damper than those accepted by Strumigenys eggersi.

Regional Information

Costa Rica

Longino (Ants of Costa Rica) - In Costa Rica gundlachi is very common in moist to wet lowland forest. It also occurs in the very wet mid-elevation forest of the Atlantic slope of the Tilaran and Guanacaste Cordilleras, but has not been observed in similar habitats in the Cordillera Central (in spite of many Winkler samples from mid-elevation sites in Braulio Carrillo National Park). It occurs in the moist evergreen forest band on the Pacific slopes of the Tilaran and Guanacaste Cordilleras, but does not occur in nearby cloud forest.

Castes

Worker

Queen

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • gundlachi. Pyramica gundlachi Roger, 1862a: 253, pl. 1, fig. 18 (w.) CUBA. Brown, 1960b: 44 (q.). Combination in Strumigenys: Roger, 1863b: 40; in S. (Pyramica): Brown, 1948e: 110; in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 120. Senior synonym of banillensis, berlesei, bierigi, infuscata, isthmica, vincentensis: Brown, 1960b: 40. See also: Bolton, 2000: 186.
  • vincentensis. Strumigenys eggersi var. vincentensis Forel, 1893g: 378 (w.) ANTILLES. Junior synonym of gundlachi: Brown, 1960b: 40.
  • banillensis. Strumigenys eggersi var. banillensis Santschi, 1930e: 80 (w.) CUBA. Combination in S. (Pyramica): Brown, 1948e: 110. Junior synonym of gundlachi: Brown, 1960b: 40.
  • bierigi. Strumigenys bierigi Santschi, 1930e: 80 (w.) CUBA. Combination in S. (Pyramica): Brown, 1948e: 110. Junior synonym of gundlachi: Brown, 1960b: 40.
  • isthmica. Strumigenys (Strumigenys) eggersi var. isthmica Santschi, 1931c: 276 (w.) PANAMA. Junior synonym of gundlachi: Brown, 1960b: 40.
  • berlesei. Strumigenys eggersi var. berlesei Weber, 1934a: 36 (q.) CUBA. Junior synonym of gundlachi: Brown, 1960b: 40.
  • infuscata. Strumigenys (Strumigenys) eggersi subsp. infuscata Weber, 1934a: 35 (w.q.) CUBA. Junior synonym of gundlachi: Brown, 1960b: 40.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Bolton (2000) - A short series (4 workers) from Colombia: El Campano, collected by W.L. Brown (MCZ) are at the upper end of the gundlachi size range (HL ca 0.52, HW ca 0.40, ML ca 0.34, MI ca 64, AL ca 0. 52); they are uniformly brown in colour. Their heads are slightly narrower and scapes consequently slightly longer than usual (CI ca 75 , SI ca 80). Their mandibles are a little stouter and with inner margins more convex than usual, and the preapical denticles are somewhat more pronounced. The ventral spongiform lobe of the postpetiole is extremely small. They may represent a close but distinct sibling species, or may be a darker coloured higher altitude population of gundlachi.

Description

Worker

Bolton (2000) - TL 1.7 - 2.2, HL 0.42 - 0.52, HW 0.34 - 0.42 , CI 77 - 85 , ML 0.25 - 0.35, MI 59 - 67, SL 0.20 - 0.30, SI 57 - 75, PW 0.22 - 0.28, AL 0.41 - 0.54 (25 measured).

Characters of gundlachi-complex; see also comparison with closest relatives in the identification section. Inner margin of mandible more or less straight to shallowly convex, with 4 - 9 preapical denticles located in the apical half or more of the length. Often the denticles very small and difficult to see easily. Pronotal dorsum without a pair of standing hairs anteriorly; pronotal humeral hair usually (but not always) flagellate. Pair of standing hairs on mesonotum sometimes simple, but may be hooked , looped apically, or have a short flagelliform apical section. Spongiform appendages of postpetiole present, small but distinct; height of ventral lobe in profile at most about half the height of the postpetiolar cuticular surface and usually less. First gastral tergite smooth when clean, without distinct shagreenate or reticulate sculpture.

Type Material

Bolton (2000):

Lectotype worker (by designation of Brown, 1960a: 40), Cuba (Gundlach) (Naturhistorisches Museum Wien, Vienna) [examined].

Strumigenys eggersi var. vincentensis Forel, 1893b: 378. Holotype worker, ANTILLES IS: St Vincent I., leeward side, forest near Chiteaubelais, 1000 ft, ix. under rotting leaves (H. H. Smith) (The Natural History Museum) [examined].

Strumigenys eggersi var. banillensis Santschi, 1930: 80. Holotype worker, CUBA: Havana, Sierra Banilla (Bierig) (Naturhistorisches Museum Basel) [not seen].

Strumigenys bierigi Santschi, 1930: 80. Holotype worker, CUBA: Havana, Marianao (A. Bierig) (NHMB) [not seen].

Strumigenys (Strumigenys) eggersi var. isthmica Santschi, 1931: 276. Syntype workers, PANAMA: France Field, 2.v.1930 (A. Bierig) (NHMB) [not seen].

Strumigenys (Strumigenys) eggersi subsp. infuscata Weber, 1934a: 35. Syntype workers and queen, CUBA: Limones Seboruco, 4.viii.1933 (N.A. Weber) ; Cienfuegos, Soledad, vii.1932 (D. M. Bates & G.B. Fairchild) (Museum of Comparative Zoology) [not seen].

Strumigenys eggersi var. berlesei Weber, 1934a: 36. Holotype queen, CUBA: Harvard Botanical Gardens, 29.viii.1933, berlesate of compost heap (N.A. Weber) (MCZ) [not seen].

References