OF THK MALTESE ISLANDS. 53 



])racticiilly all observers of their habits informed nie that they occur most freely 

 aud are most troublesome during the hot, dry mouths of the year. It is 

 highly probable that successive broods are produced during the summer months, 

 but as the larval stage occupies apparently a long period, the successive 

 generations can be produced only at extended intervals. 



As to whether the larvte occur most frequently during the summer remains to 

 be seen. It is my impression, however, that they may be found more abundantly 

 in autumn and winter than at any other season, and careful search should be 

 made for them a week or so after the adults have disappeared. 



Prophylactic Measures. 



In consideration of the facts which have so far been brought to light regarding 

 the economy of Phlehotonnis, it is clearly evident that the task of suppressing 

 these insects is an almost insurmountable one. Had we to deal with insects as 

 large and as accessible as mosquitos, the adoption of prophylactic measures 

 would be comparatively easy, but owing to the extremely minute size aud almost 

 tlea-like habits of the adult insects, and the enormous area over which the 

 breeding-places may occur, we are faced with a problem which is most difficult 

 of solution. 



As I was unable to devote any time to experimental work bearing upon the 

 control of these pests, the only course open to me now is to suggest a few 

 measures which may ameliorate the existing conditions and lead to a reduction 

 of the malady of which these insects are transmitting agents. It seems to me, 

 however, that the only practical way of grappling with this question is to 

 proceed tentatively at first, and although I have discussed an extensive field of 

 operations which may be directed against these insects, I would pin my faith 

 rather to some of those measures which are considered under the following 

 headings. But in the first instance it must be borne in mind that precautions 

 against the bites of blood-sucking insects, though feasible to intelligent and 

 well-to-do persons, are not as a rule employed by the mass of the people. Yet 

 any prophylactic measures which are calculated to diminish the infection, even 

 in a small degree, should be seriously and persistently employed. 



Repellents. — I had no opportunity of demonstrating the value of these by 

 experiment owing to my immunity from the bites of these insects, but I was 

 assured that several good formulas were in general use, though proprietary 

 preparations were rarely employed. Judging by the testimony of those who 

 had used such deterrents, one of the best was that which was prescribed by 

 Major Crawford, K.A.M.C, and I am extremely indebted to him for giving me 

 permission to embody it in this report. It is composed of the following 

 ingredients : — 



Ol. Anisi, 3 grs. 



01. Eucalypti, 3 grs. 



01. Terebenth, 3 grs. 



Unq. Acid Borac. 

 Spruyin;/ with repellents. — The least objectionable of these, and at the same 

 time one of the most eft'ective, is formol or formaldehyde. The dark portions 



