GLOSSINA INVESTIGATIONS IN NYASALAND. 255 



delicacy that unless one's attention had been attracted by corresponding movements 

 of the labial palpi the operations in progress would have been undetected. From 

 time to time a sharp turn of the head through a quarter of a circle on each side also 

 went on. 



After half an hour's work the Mutilla retired a short way from the pupa and, resting 

 on its side, cleaned its antennae and rubbed its legs together, but then manifested 

 some uneasiness at the light, for at this point I had to watch it by lamp hght, and 

 concealed itself. But when the light was very much shaded, it returned to the 

 pupa, put its head to the site of its previous operations, where with a lens I could see 

 a small breach of surface, and then gradually raising the hinder part of its body so 

 as to rest again on its head, recommenced work, its antennae being this time in 

 front of its head, but resting on the pupa. Occasional movements of anteflexion 

 of the abdomen then took place, as if the insect were preparing for oviposition, and 

 finally, after at least an hour's work, the insect resumed the horizontal attitude 

 on the pupa, and having examined its work advanced so that its hinder end came 

 somewhere over the breach. It then moved to and fro, feeling for the exact spot, 

 and then remained still, doubtless in the act of oviposition, running away a few 

 seconds later. 



Though the female worked so indefatigably, so tiny a puncture was produced as 

 to be barely visible except in a certain light to the unaided eye, and it appeared 

 moreover as if definitely sealed by the insect with some secretion after oviposition. 

 This may possibly be a very important part of its final operations, as on several 

 occasions I have found an exuberant fungus growth, brown in colour, sprouting at 

 little fissures accidentally produced in tsetse pupae. By and by I hope to be able 

 to study this further. 



I should perhaps add that the night when the Mutilla was w^orking was bitterly 

 cold, a rather surprising fact, seeing that as a rule these insects are so lethargic 

 except on bright sunny days. 



I have now examined carefully all the pupae to which this female has access, and 

 seven out of the twenty show this evidence of attack. There is therefore every 

 reason to believe that the Mutilla can be raised experimentally in some numbers 

 and without any great difficulty in the laboratory. Their hardiness, their activity 

 in finding food for themselves and their longevity make them singularly easy to 

 deal with, so that I expect shortly to be able to submit a further report on the 

 subject. "^ 



In regard to their general habits, they do not as a rule become active till the 

 middle of the afternoon, remaining until then hidden beneath objects on the top 

 of the ground, or buried beneath the superficial layers of the soil. The female is 

 an adept at burrowing, and the male in pursuit of her does not hesitate to force his 

 way into the soft earth. Both sexes run with extreme activity, the male being 

 unusually loth to take to flight for a winged insect. The females in captivity soon 

 lose the quality of shyness, which is so marked during the first day or two after 

 emergence, and wiU then run about unconcernedly, even though one is moving 

 objects in the jar, almost as if they had learnt that they were unlikely to be molested. 

 (C205) d2 



