Cyphomyrmex faunulus Wheeler 1925

(Figs. 5, 15, 31, 47)

Cyphomyrmex bigibbosus faunulus Wheeler , 1925: 44-45 (Worker, female; British Guiana: Kartabo, Camaria; Bion.). - Weber, 1938: 187 (British Guiana: Forest Settlement, Mazaruni River). - Weber, 1946: 124-126, pls. 2. 8 (British Guiana; Bion.).

Cyphomyrmex bigibbosus : Weber, 1938 (nec Emery, 1894): 203 (Bolivia: Convendo, Huachi, Lower Rio Madidi, Cachuela Esperanza, Won, Riberalta). - Weber, 1940: 413 (Key). - Weber, 1945: 14-16 (British Guiana, Trinidad; Bion.). - Weber, 1946: 122-124, Pl. 1 (British Guiana: Oronoque River;.Bion.).

Cyphomyrmex bigibbosus petiolatus Weber , 1938: 187-188 (Worker, female; Bolivia: Lower Madidi River, Cavinas). - NOV. SYN.

Types. - Workers and female of faunulus (MCZ) from Kartabo (type locality) and Camaria, British Guiana, and a worker of petiolatus (NAW) from Lower Rio Madidi, Bolivia, examined.

Distribution. - This species ranges from Trinidad over the Guianas through the Amazon river valley to the Beni river valley in western Bolivia.

Specimens examined: British Guiana: Kartabo (W. M. Wheeler) 2 workers, 1 female (lectotype and paratypes of faunulus ) (MCZ); Camaria, 1 worker (paratype) (MCZ); Oronoque River (N. A. Weber) 1 worker, 1 female (NAW); Forest Settlement, Mazaruni River (N. A. Weber) 2 workers (WWK). - Brazil, Amazonas State: Manaus (K. Lenko) several nest series with many workers, several females and males (DZSP, WWK), Benjamim Constant (K. Lenko) 1 nest series with many workers and 1 female (DZSP, WWK). - Bolivia: Covendo (W. M. Mann) 1 worker (WWK); Ivon, Beni River (W. M. Mann) 3 workers (WWK); Lower Madidi River (W. M. Mann) 1 worker (syntype of petiolatus ) (NAW).

Discussion. - It was shown above that the typical bigibbosus is identical with the race later described by Weber as tumulus . It remains here to decide the fate of the other forms hitherto recognized in the tightly knit complex: " bigibbosus " (of authors, not of Emery), faunulus and petiolatus , neatly differentiated in Weber's (1940: 413) key. From the material which I was able to gather, I reached the conclusion that they are not separable, but constitute a single species, that takes the oldest available name viz. faunulus .

C. faunulus was thought to be a rather small race of what had wrongly been taken as the typical bigibbosus . The type series of the former is indeed on the lower range of the measurements for the species in the presently accepted sense, but this alone is not significant. The additional character given by Weber (1940: 413), viz. length-width proportion of the postpetiole ( faunulus and petiolatus with the postpetiole broader than long, " bigibbosus " with the postpetiole as long as broad), likewise does not seem to work. Moreover, petiolatus workers, as Weber (1938: 188) himself confesses, "are unsatisfactorily separated from the typical form" (= " bigibbosus "), the scape character given in his key (1940; 413) both contradicts the original description and a syntype specimen. The female of petiolatus , which unfortunately I did not see, is surely more distinct by its broader petiole and postpetiole. However, the evidence is not enough for recognizing a discrete form and 1 rather place petiolatus into synonymy of faunulus .

Variation. - Besides the differences in the female caste, as given for the race petiolatus , 1 have an even more striking variant from Manaus (DZSP n. 2198) which shows both in the worker and in the female caste a conspicuous pair of gibbosities on the anterior third of tergum 1 of gaster. This nest series agrees however with all other essential features of faunulus .

Bionomics. - Following is a brief digest of observations on faunulus bq Wheeler (1925: 45) and Weber (1946: 124-126), and on " bigibbosus " (= faunulus !) by Weber (1945: 14-16; 1946: 122-124), made in British Guiana and Trinidad.

C. faunulus is a rain-forest species. Its colonies are small, and the nests are usually found in rotted wood, but also in tangles of epiphyticroots, abandoned termite mounds and in the soil (clay stratum of an Atta mound!). The cavity size is variable, the volume varying approximately between 5-50 cc. The fungus garden is either sessile with lateral attachments to the wall, or pendant. The substrate consists of insect excrements, vegetable debris, seeds, woody fibers; it often includes parts of skeleton of ants (Ponerinae, Cephalotini), presumably used as framework. The bromatia are variable in aspect, their consistency transitional between those of Trachymyrmex and C. rimosus .

In captivity, C. faunulus specimens rejected dry chemical food such as hemoglobin, blood fibrin, egg albumen, dextrin, gelatin, peptose, maltose, diastase, but accepted bromatia from C. rimosus gardens grown on farine. Workers also lapped up eagerly the body juices of a crushed mosquito. They feign death when disturbed. Among inquilines have been registered a small milliped and an attophilous thysanuran.

Note. - The figures of the worker have been made from a very large worker taken by Mann at Covendo, Bolivia.

Cyphomyrmex faunulus é uma espécie de inseto do gênero Cyphomyrmex, pertencente à família Formicidae.