510 Phylum Arthropoda 



placed in a shallow pan of water to prevent the escape of the ants. 



This type of nest is best adapted to the study of the life history of 

 the ant and such other studies as require only one or two examinations 

 per day. The material in the bottom may easily be searched for young. 

 Black or other dark colored paper is preferable, as the eggs and larvae 

 are white. 



Feeding. The food required for this species of ant is of the usual 

 kind: Apples, bananas, honey, syrup, sugar solution, and fresh insect 

 bodies (preferably cut into small pieces). Ants are cannibalistic and 

 eat their owm eggs and young. It is therefore necessary to provide them 

 with ample food. 



Life history data. The ants are most easily obtained in late fall, 

 winter, or early spring during the period of hibernation. At this time, 

 they form dense clusters below the frost line. They are also so sluggish 

 at this time that they do not eject the little droplets of formic acid 

 which is so pungent that it may kill them during transportation to the 

 laboratory. They should, however, be handled gently, even at this time 

 of year to prevent the secretion of formic acid. Workers and sexually 

 mature wingless females may be obtained during the period of hiberna- 

 tion. Emergence from hibernation begins about the middle of April. Egg 

 laying begins the latter part of April and continues up to the first few days 

 of June. Larvae may be obtained in the field from the middle of June 

 until the middle of August. Worker pupae are obtainable from the middle 

 of June to the latter part of October. The large pupae of the reproducing 

 males and females are obtained in July and the winged males and fe- 

 males appear about the middle of that month when mating occurs. In 

 the laboratory, eggs appear in the nests as early as January. 



These data are based on observations made in the Chicago region. Al- 

 lowance must be made for differences in the life history periods with 

 different localities. 



SOME AIDS TO THE STUDY OF MOUND-BUILDING ANTS 



E. A. Andrews, Johns Hopkins University 



FOR breeding ants in captivity a compromise must be made between 

 the need of the observer to see the ants and the need of the ants to 

 be screened from some of the rays of light and to be supplied with food 

 and moisture at certain temperatures. When large ants such as the 

 mound-building ant, Formica exsectoides, are to be studied in regard to 

 feeding, direction-finding and the like, some special adaptations of the 

 usual formicaries are advisable. 



Transplanting of mounds may be done in winter or summer. In each 

 case much of the old mound may be transported for quicker rebuilding 



