50 B. NEWSTEAD — THE PAPATACI FLIES (PHLEBOTOMUS) 



failure was the result. As to the detection of the ova in a state of nature I 

 believe this to be a practical impossibility, as when laid upon dark substances 

 thej become absolutely invisible and can be detected only by the aid of a 

 microscope. Even when laid in captivity in confined areas they are most difficult 

 to detect, and under the most favourable conditions can be seen only when laid 

 upon colourless or transparent surfaces such as white paper or the surface of a 

 glass tube. 



Habits and occukrenoe op the Adul'J' Flies. 



Though so evasive in their early stages, the adult flies may be found almost 

 everywhere throughout the Island in favourable situations or localities. They 

 outnumber the mosqxiitos, and the females may be included among the most 

 vicious of all the blood-sucldng Arthropods. They are distinctly "domestic " 

 in their habits and may be considered among the most detestable of all 

 man's "iminvited guests." It is a curious fact, however, that they have their 

 likes and dislikes both in regard to hosts and habitats. I can fortunately place 

 myself among the small numbers of those who have proved immune to the bites 

 of these blood-sucking pests ; or at least I have never consciously experienced 

 the effect of their bites, any more than I have in the case of PuJe.r irritans. 

 And this is all the more extraordinary because fresh comers to the Island, 

 especially children, generally suffer torture from the bites of these insects, and 

 many cases are admitted to the hospitals through the infection which the Papataci 

 flies are known to convey. To say the least, they are an intolerable nuisance in 

 every part of the world in which they are known to occur. Man is evidently, 

 not the only vertebrate which these insects attack, as examples were frequently 

 found which had filled themselves to repletion with the blood of the domesticated 

 rabbit ; so that it is evident that they are not entirely dependent upon man for 

 food and the probabilities are that they subsist and flourish on any of the warm- 

 blooded animals when man is not available. 



My experience with regard to the favoured haunts of these flies is almost 

 precisely the same as that of other investigators. In certain parts of the island 

 they were found to be abundant, while in others, for some imaccoimtable reason, 

 they occurred very sparingly, though the conditions necessary for breeding- 

 purposes, especially stone walls, abounded everywhere. In badly infested 

 regions, too, they favoured certain dwellings much more than others ; of two 

 hotises occupying the same aspect and surroundings, or a section of the same block 

 or street, one was often found to be infested while the other was rarely visited. 

 It was noted also that there was a marked domiciliary distribution in many 

 houses. Bedrooms on the first floor, especially those occupying a position on 

 the lee or sheltered side of the house, were particularly favoured, while those on 

 the opposite side of the building were rarely visited ; and rooms at a greater 

 elevation (second floor), which I had under close observation for a considerable 

 time, were only once found to contain a single example. 



The naval and military camps at Ghain-Tuffeiha afforded also a remarkable 

 instance of the local distribution of these flies, the naval camp on one 

 side of the plain being badly infested, while the other and more extensive 

 camp was said to be practically free from the invasion of Phlehotomus. This 



