PHLEBOTOMUS: EARLY STAGES 185 



and where large crevices are left into which the}' can pass. The females 

 are most active on still sultry nights, and then as they become replete 

 with blood they cannot readily pass through the meshes of the 

 ordinary mosquito netting. The males, if present, nearly always escape. 

 When trying to catch one of these flies it will be noted that they make 

 short leaps like the hop of a flea. 



Only the females suck blood, but Marett notes that both sexes may be 

 seen burying their mouth parts in organic matter. The same observer 

 states he has seen female sand flies, replete with fresh blood, coming 

 out of a hole in a wall, and suggests that they had probably fed on rats. 



The breeding grounds of any species of Phlebotomus are extremely 

 difficult to locate. The small size of the larvae, their colour, and the places 



in which they are likely to be found, all increase the 



Early stages 

 difficulties. It is interesting to read- even Newstead's 



account of his efforts in this direction in Malta, in which he only found 

 a few larvae after prolonged and repeated search. In spite of the 

 difficulties the worker should always endeavour to locate the 

 breeding grounds of any species of Phlebotomus, as all information 

 will prove of the utmost value to other workers in the same field. 



Grassi found the larvae of P. papatasi in all kinds of damp refuse in 

 cellars, and particularly on the sides of drains where water splashes or 

 trickles down. In Malta, Newstead found the larvae in caves, and in 

 crevices and fissures under loose rocks where there was some damp 

 earth ; they were at some distance from the surface. They were also 

 found low down near the foundations of stone walls, and on the under 

 surfaces of stones. In all these places there was organic matter of all 

 kinds, chiefly the excreta and remains of insects, wood lice, etc., as well 

 as sufficient moisture and absence of light. It should be noted that, as 

 Newstead points out, the larvae of Phlebotomus have the habit of 

 flicking themselves off the surface of the stone or other object when 

 exposed to light, and are easily lost. The pupae are the most difficult 

 to detect, as their colour harmonizes with their surroundings. 



Marett reports having found the larvae in wells, latrines, tanks, venti- 

 lation shafts and manholes, but the chief breeding places in Malta, 

 according to this observer, are stone walls which are dry above ground 

 level, but moist below the surface. 



Hewlett found larvae in the following situations at Pusa, Bengal : 



1. The nearly dried mud of a cement channel, leading from a well 

 reservoir. 



2. A small heap of kitchen refuse near the base of a wall. 



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