89 



ON TWO VARIETIES OF GLOSSINA MORSITANS 



FROM NYASALAND. 



By Dr. J. O. Shircore. 



Medical Officer, Sleeping Sickness Investigations, Nyasaland Protectorate. 



G-lossina morsitans, Westw., var. pallida, nov. 



Thorax slate-grey, pattern indistinguishable ; scutellum with two dark tri- 

 angular areas which are contiguous at their upper inner angles. Abdomen with 

 the darker blotches on each side o£ the second segment very faint ; on the other 

 segments the banding is not a prominent feature, as it is in the typical form ; the 

 bands olive-grey, their margins being distinct and defined from the ground-colour, 

 which is a few shades lighter. In the middle line the banding is cut off square, 

 leaving a very narrow straight line down the centre of the segments ; the outer 

 margins of the bands sloping away from below upwards and leaving light areas 

 on each side. Legs with all the joints of the front and middle tarsi pale, except 

 the distal end of the latter which has a faint darkish ring ; the last two joints of 

 the hind tarsi faintly dark, but nothing like so dark as in G. morsitans. Wings 

 tinged with light yellowish-brown. 



Nyasaland : 1 rf , Dowa district, 6. v. 1912. 



Type in the British Museum. 



This fly was picked out at a glance from more than a hundred G. morsitans, 

 and is distinctly and remarkably paler throughout, 



Glossina morsitans, Westw., var. paradoxa, nov. 



Superficially resembles G. morsitans in appearance and size, but the hind tarsi 

 are entirely dark, as in the palpalis group. The superior claspers of the male 

 genitalia resemble those of G. suhmorsitans, as figured by Prof. Newstead, 

 but are more deeply pigmented throughout, and especially along the lateral and 

 posterior borders. 



Nyasaland :1c?, Nyamsato, near Chunzi, Dowa district, 4. vi. 12. 



Type in the British Museum. 



If casually observed, this tsetse would probably be taken for an ordinary 

 G. morsitans ; but if the abdomen had become discoloured it might well be 

 mistaken for G. palpalis. The superior claspers have only been looked at with 

 a hand-lens ( x 12) ; they were prized open and examined in situ. 



[There is in the British Museum a single male which agrees entirely with the 

 specimen described above as var. pallida. Mr. E. E. Austen has made a 

 preparation of the genitalia, and they are certainly indistinguishable from those 

 of typical G. morsitans. This specimen was taken by Dr. M. Sanderson on the 

 Chitala stream, Dowa district, 12. xi. 1910. — Ed.] 



Bull. Ent. Res. iv, pt. 1, May 1913. 



