12 BULLETIN- 445, U. S. DEPARTMENT OF AGEICULTUBE. 



These ants are black and about half an inch in length. The head 

 in proportion to the body is large. The species is probably closely 

 related to the leaf-cutting ant of Texas and Cuba {Atta sp.). While 

 they cut the leaves of practically any plant, they appear to be par- 

 ticularly fond of orange leaves, and it is not infrequent in Brazil to 

 see a good-sized orange tree nearly defoliated in a single night. The 

 leaf-cutting ants are practically agricultural ants. The fragments of 

 the leaves cut from the trees are carried into a chamber in their nests. 

 Here they decay and form the basis for their so-called " mushroom 

 garden." The' fungi that are cultivated upon these small bits of de- 

 caying leaves supply the food of the entire colony. It is reported, 

 and doubtless is true, that these gardening ants exercise every pre- 

 caution to prevent their mushroom beds from becoming contaminated 

 by other species of fungi. The Brazilian farmer combats this pest 

 by forcing hot fumes of sulphur into the runways. 



In view of the fact that no serious effort is made to combat insect 

 or fungous enemies other than the saiiva ant, the comparatively 

 small amount of injury which such enemies appear to do is remark- 

 able. 



THE ORANGE CROP OF BAHIA. 



While ripe oranges are obtainable in Bahia every month in the year, 

 there are two principal seasons, one in June and July and the other 

 in December and January. The June crop is considerably the larger, 

 and the fruits are considered by Bahians much sweeter and juicier 

 than those which ripen in December. 



It is difficult to estimate the average yield per tree. The number 

 counted on numerous trees examined at the beginning of the Decem- 

 ber season varied from a few dozen to nearly 500, with an average 

 of about 250. In groves which had been manured and were gener- 

 ally well cared for, the trees usually carried from 300 to 400 fruits, 

 and this, it must be remembered, does not include the fruit produced 

 in the June crop. Where the trees received good care the yield will 

 probably compare ver}^ favorably with that in California. (PI. V.) 



While pruning shears are occasionally used in picking, the fruit 

 is usually pulled from the tree and either allowed to fall to the ground 

 or dropped into a sack. Sometimes the peddlers who come from the 

 city to buy the fruit lead their horses or mules into the grove and 

 toss the fruits from the tree into the large baskets, called " cassuas," 

 strapped on each side of the animals' backs. Frequently the fruits 

 are graded into two sizes before being carried into the city for sale. 



Careless picking and handling naturally result in many injuries, 

 such as gravel bruises, abrasions, and punctures of the skin. These 

 must, of necessity, encourage the growth of blue mold and other 

 fungi, but the effect is not so serious as it would be if there were a 



