pronotal spines
promesonotum with 3 pair of spines
promesonotum with 3 pair of spines
The promesonotum is armed with at least three pairs of spines and teeth. Usually the anterior pairs are large and robust, and the posterior pair is smaller. Used in Antkey to separate Acromyrmex from Atta.
2 pair promesonotal spines
2 pair promesonotal spines
The promesonotum armed with two pair of spines or teeth. Usually the anterior pair is large and robust, and the posterior pair is smaller. Used in Antkey to separate Acromyrmex from Atta.
pronotal spines absent
pronotal spines absent
The pronotum or promesonotum lacking spines or teeth. At most it is armed with blunted humeral angles. Used in Antkey to separate all other myrmicine genera from Atta and Acromyrmex.
pronotal spines weakly arching
pronotal spines weakly arching
The pronotal spines are straight, or weakly arching anteriorly. This character may be informative for separating Atta sexdens from Atta cephalotes, but attine pronotal spines show considerable infraspecific variation and this character may well prove unreliable, and thus must be used with caution.
pronotal spines present
pronotal spines present
The pronotum or promesonotum armed with 1-3 pairs of spines or teeth. Used in Antkey to separate Atta and Acromyrmex from all other myrmicine genera.
pronotal spines strongly arching
pronotal spines strongly arching
The pronotal spines are strongly arching anteriorly. This character may be informative for separating Atta cephalotes from Atta sexdens, but attine pronotal spines show considerable infraspecific variation and this character may well prove unreliable, and thus must be used with caution.
pronotum with spines
pronotum with spines
pronotum armed with spines