February, '16] :\ICCOLLOCH and HAYES: solenopsis molesta 29 



it transformed to the semi-pupal stage. The semi-pupal stage was 

 found in midsummer to range from 2 to 11 days. 



Large larvse have often been encountered, in nests of this species, 

 which were, undoubtedly, either larvae of males or queens. None 

 were ever reared successfully in artificial nests. Except for their 

 much greater size, they seem to resemble the worker larvae, and upon 

 reaching their final stages of growth undergo similar changes. 



Pupa. — ^The comparative sizes of the worker, queen, and male 

 pupae are shown in Plate 2, figure 7. The worker is the smallest, 

 the male intermediate, and the queen the largest. The three forms 

 are white during the earty stages of pupal development, but as 

 development proceeds they gradually assume the color of the 

 adult form. The queen and worker pupae become a pale yellow, 

 almost as dark as the adult. The male changes to a dark brown be- 

 fore transformation. 



The length of the worker pupal stage was found to be from 13 to 27 

 days. The same period for males and queens has not been determined. 

 Worker pupae, when ready to transform, are assisted in shedding their 

 pupal skin by attendant workers. This skin is torn off in the form of 

 a thread over the long axis of the body as one would unwind a skein 

 of yarn. Pupae are not enclosed in cocoons. 



Adult. — This species has but three kinds of adults, workers, males^ 

 and queens. There are no major and minor workers or soldiers. 

 Workers, after emerging from the pupal stage, are very pale yellow in 

 color and helpless. They are cared for by attendant ants which carry 

 them about. In from two to three days these callows become thor- 

 oughly pigmented and are able to care for themselves. The worker 

 (PI. 2, fig. 4) is one of our smallest ants, being from 1.5 to 1.8 mm. 

 long and is pale yellow in color. Vestigal eyes are present. The 

 antennae are ten-jointed. Spines are absent on the metathorax. The 

 pedicle is two-jointed and the abdomen is armed with a sting. Say 

 (1) in his original description says, "Their sting is like the puncture 

 of a very fine needle." In two years' handling, the writers have never 

 been stung by this ant. Workers constitute the greater part of the 

 colonies. 



The queen (PI. 2, fig. 5) is of the same general yellow color as the 

 workers with a darker (almost brownish) color on the head, prothorax, 

 and between the dorsal abdominal segments. The prothorax is 

 unarmed. Before fertilization, the queen has two pairs of hyaline 

 wings which are lost after mating occurs. Antennae are eleven- 

 jointed. 



Males are intermediate in size between the queens and workers. 

 Their length varies from 3.5 to 3.6 mm. The legs and antennaB are 



