1913] Stomoxys calcitrans Linn. 201 



versely across the fourth segment. This section falls away 

 and the fly escapes. Prior to this the nymph undergoes its 

 final ecdysis, pushing its effete skin off backwards into the 

 posterior end of the puparium. On its emergence it appears 

 as a small dark fly, gray in color, with thick rudimentary 

 wings of a dull leaden color. Its head is, at this stage, much 

 wider than the thorax, and the abdomen is attenuated. At 

 first it is very active, the period of activity evidently serving to 

 allow the fly to force its way to the surface before the wings 

 are fully grown and stiffened. The frontal sac is constantly 

 inflated during this time, and no doubt serves in moving frag- 

 ments of earth, etc. out of the way. When liberated the 

 insect spends considerable amount of time in combing out the 

 hairs on the arista of the antennae. 



During this time the fly constantly changes its position, 

 and the frontal sac is -contracted. There are marked changes, 

 too, in the abdomen and wings. The abdomen first becomes 

 longer, and is constantly expanded and contracted, and grad- 

 ually assumes its normal coloring, with the clove spots. The 

 wings then begin to expand, a process which is completed in 

 less than five minutes. 



The fiy is about its normal size, shape, and color at this time, 

 but some time is taken in the final hardening of the integument, 

 and in the final combing operations, which seem to be indispen- 

 sible before flight. It is during this last process that the 

 proboscis is at last raised into its horizontal position. 



REFERENCES. 

 See Bibliography given in Part I, and also: 

 Newstead, R. 1907. Stomoxys calcitrans Linn. Ann. Trop. Med. and Parasit. 

 Vol. I. 1907. Liverpool. 



DESCRIPTION OF PLATE XXII. 



Fig. 1. Egg, greatly enlarged, showing groove, and point of emergence of the 

 larva, e. 



Fig. 2. Lateral view of anterior segments of larva, showing ant, antenna; m, man- 

 dible; h. s., hypostomal sclerite. 



Fig. 3. Dorsal view of anterior segments of larva of Stomoxys calcitrans. m, 

 mandible; t. s., thoracic spiracle. 



Fig. 4. Openings of thoracic spiracle. 



Figs. 1, 2, 3 and 4. After Newstead. 



Fig. 5. Semi-diagramatic view of adult fly. See Part I. 



Fig. 6. Salivary glands and left Malpighian tube of adult, see Part I. 



Fig. 7. Male reproductive organs: t, testis; v. s., vesicula seminalis; e. d., ejac- 

 ulatory duct; r, rectum. 



Fig. 8. Female reproductive organs: o, ovary; ov, oviduct; u. g., uterine gland; 

 11, uterus; r. s., receptacula seminis. 



