The following are the species of ants which I have observed on the Riviera, and principally at Mentone; the actual locality where my notes were taken being given in every case.
Family Formicidæ.[41]
[41] Ants have been divided into three tribes, the two first of which, Formicineæ and Ponerineæ, are distinguished by the latter having a contraction in the abdomen not found in the former, and both are separated from the third tribe, Myrmicineæ by having but a single scale on the petiole, while in Myrmicineæ there are always two nodes or protuberances on the petiole. It is important to remember the difference between the first and the last named tribes, as we shall find that all the true harvesters belong to Myrmicineæ. I have not seen any of the representatives of the second tribe in the south.
Tribe Formicineæ.—Petiole (or stalk which unites the thorax and the abdomen) of one joint, and furnished with a single vertical scale, abdomen not contracted.
(1) Formica fusca, Linn.—A rather large ant (31/2 to 41/2 lines long), of a blackish ash colour, with a satiny sheen on the upper half of the abdomen. Smells of formic acid when crushed. Lives upon sweet secretions and animal matter, and occasionally carries a very few seeds into its nest, which is made in the ground. (Mentone.)
(2) F. emarginata, Latr.—Of medium size (21/2 lines), brownish, with yellow thorax. Has a strong smell of honey when crushed. Lives principally upon sweet secretions, but occasionally carries a very few seeds also. Nest in the ground. (Mentone.)
(3) F. (Camponotus) cruentata, Lat.—Large (5 to 6 lines), dusky brown, with orange red on legs and abdomen. Strong smell of formic acid. Lives on sweet secretions and animal matter, and has never been seen by me carrying seeds. Nest in the ground. (Mentone and Cannes.)
(4) F. (Camponotus) marginata, Latr.—Large (4 to 51/2 lines), black. Has no perceptible smell even when crushed. Lives principally on sweet secretions, and does not bring in seeds to its nest, which is made in the ground. I have seen this ant at Cannes ascending the cork oaks in search of certain cocci which resemble black and shining berries rather larger than a pea, and which exude sweet secretions. (Mentone and Cannes.)
(5) Formica cursor, Fonscol.—A rather large but slender ant (3 to 4 lines long), nearly black, with a faint bronzy hue, legs very long. Smell not noted. Runs very swiftly, and is hard to catch; feeds on sweet secretions, and does not carry seeds. Nest in ground. (Cannes.)
(6) F. (species undetermined).—A large ant (5 to 61/2 lines), black brown with yellow thorax and legs. In shape resembles F. marginata. Strong smell of formic acid. Habits not observed. Nest found under a stone in a pine wood. (Cannes.)