Strumigenys smithii, Forel

Forel, A., 1893, Formicides de l'Antille St. Vincent. Récoltées par Mons. H. H. Smith., Transactions of the Entomological Society of London 1893, pp. 333-418 : 375-377

1. Strumigenys smithii, Forel .

(No. 24 a a 24 f). [[ queen ]] [[ male ]].

[[ worker ]]. Un peu plus petites que les types de Blumenau.

[[ male ]] (encore inedit). L. 2, 7 a 3 mill. Tete arrondie, un peu plus longue que large; mandibules beaucoup plus courtes que chez la S. baudueri, Emery , [[ male ]] (au contraire de l'ouvriere 1). Mandibules striees, courtes, arquees, epaisses a la base, sans bord terminal, terminees par une longue dent pointue et luisante. Antennes longues, filiformes; scape seulement un peu plus long que large et que le 1 er article du funicule. Epistome a peine avance devant. La tete est beaucoup plus large et plus courte que chez le S. baudueri . Face basale du metanotum oblique, en long talus, presque deux fois longue comme la face declive, dont elle est separee par une dent presque imperceptible. Face declive bordee d'une arete tres basse. Los deux articles du pedicule comme chez l'ouvriere et entoures de la meme facon des memes masses chitineuses areolaires. Valvules genitales exterieures obtusement triangulaires, d'un jaune blanchatre.

Tete et thorax fortement reticules-ponctues et mats; pedicule et abdomen lisses et luisants. La sculpture du pronotum et du meso- notum est forte et irreguliere, celle du metanotum plus faible (subopaque); cotes du thorax en partie lisses et luisants. Quelques poils epars. Pattes seulement pubescentes. Tete noire; abdomen brun fonce; pattes et antennes brun jaunatre; le reste d'un brun rougeatre. Ailes teintes de brunatre.

[[ queen ]] (encore inedite). L. 3 mill. Ailes manquent. Dents du meta- notum plus solides, moins membraneuses que chez l'ouvriere. Scutellum non proeminent en arriere. Du reste comme l'ouvriere.

Mons. H. H. Smith ecrit du No. 24 ( Strumigenys smithii ): - " The cavities in which these ants are found are always black inside, as if with some fungoid growth. " Ce fait est du plus haut interet et fait presumer que certaines Strumigenys ont comme leurs proches voisines, les Atta , Cyphomyrmex , etc., l'habitude de cultiver des champignons. Les belles recherches toutes recentes du Dr. Moeller a Blumenau ont demontre dans tous leurs details les habitudes mycophages des Attini presumees par Belt. La systematique m'a prouve (Bullet, soc. ent. suisse, 1892) que les Attini sont intimement lies aux Dacetonini [ Strumigenys , etc.), et m'a fait supposer que les Attini sont les derives secondaires, ce qui est d'autant plus probable qu'ils sont bornes au continent americain, tandis que les Dacetonini sont repandus dans le monde entier, meme en Nouvelle Zelande. Or l'instinct mycophage des Dacetonini, s'il se confirme generalement, est evidemment primitif, c. a. d. primordial, bien moins complexe et moins developpe que chez les Atta qui vont couper des feuilles pour y faire pousser leurs champignons.

These ants are rather common in shady places. The formicarium is generally under sod or rubbish on a rock; sometimes in rotten wood. It is simply a small chamber (one or two inches long), with an entrance passage; or, if there are other passages, I have not discovered them. The ants are found crowded in the chamber with their larvae, and sometimes males and females. They are very sluggish. The colony may contain several hundred.

(24). Pretty common in partly decayed wood, shady or open places. The ants are found crowded thickly in dry cavities, generally an inch long and wide, and half an inch high; with them are larvae, and sometimes males, but I have found no females. The workers are very sluggish, hardly moving when the nest is disturbed; so that they may be picked out one by one with the forceps. The males are more active. The cavities in which these ants are found are always blade inside as if with some fungoid growth. Occasionally these ants make nests at the roots of grass, & c.

(24 a). Near Palmyra Estate (leeward), Nov. 3 rd, 1000 ft. Open field, near a stream, in a half-rotted log. The ants were found thickly crowded in a small cavity of a knot, well in from the surface; I could not discover the entrance. All that I could find were taken, and I think few were lost. The log was split up without finding others.

(24 b). Fitz-Hugh Valley (leeward); shady place, 500 ft., Nov. 4 th, in a log. There were two adjoining chambers, apparently of the same colony. The males in one chamber were more mature.

(24 c). Forest, Morne a Garou, 1500 ft. Oct. 27 th. Found on a leathery fungus growing on log.

(24 d). Fitz-Hugh Valley. Near No. 24 b. Nov. 4 th. Under rotting banana-leaves on a stone.

(24 e). Bowwood Valley, near Kingstown, 600 ft. Oct. 15 th. Clearing; scattered under the bark of a decaying log.

(24 f). Petit Bordelle Valley, 1200 ft. Nov. 13 th. Shady banks of stream; under sod on a rock. From some confusion in the notes I cannot describe the formicarium.

I have found workers of these ants foraging in the daytime in a dark outhouse. Golden Grove Estate (leeward), 300 ft. They move about slowly.