670 PROCEEDINGS OF SECTION I. 



Mr. H. Nicholls of Hobart, who has made a special study of 

 fleas, tells me that even fleas, which have no visible eyes, are 

 extremely sensitive to light. The two fleas which in temperate 

 climates cause the most annoyance are the human flea, Pulex 

 irritans, and the dog flea, Ctenocephalus cants. Pulex cheopis, which 

 is the flea which has generally carried the Bacillus pestis, has well 

 developed eyes and shuns the light. Thus we see that sunlight is 

 not only Nature's most powerful germicide, but also pulicide. 

 Surely in sunny Australia more advantage might be taken of this 

 in as far as possible insisting that there be no narrow culs de sac 

 or dark flea-breeding haunts, more especially in the vicinity of the 

 wharves of our chief ports. 



With regard to bugs, which are of interest in so far as that 

 the bed-bug at least has come under the ban of the epidemiologist 

 as the carrier of the spirillium of relapsing fever ; at the Mt. Eden 

 Gaol, Auckland, N.Z., at one of the receiving cells we were able to 

 get rid of these pests by swabbing out with kerosene. An interesting 

 observation with regard to these insects was made in a house in 

 Auckland, where I had occasion to cut through seven layers of wall 

 paper, namely, that between the fourth and fifth layer there were 

 numbers of bugs. 



Tliis habit of living behind old wall papers may account for 

 the failure which recently attended an attempt to kill these insects 

 by fumigation with cyanide in a house in Hobart. Stripping and 

 spraying with izo-izal, however, was successful. 



Another interesting point which came under our notice was 

 that on the successful extermination of cockroaches by a preparation 

 made by Mr. Pruden of Tauranga, N.Z., on some old ships, bugs 

 came more into evidence. As a matter of fact, Inspector Franklin 

 of the New Zealand Health Department, after exterminating cock- 

 roaches at the Tararua Old Men's Home at the Thames had to 

 reintroduce cockroaches to keep down the bugs. In any effort to 

 exterminate a pest by introducing some other natural enemy of the 

 pest, one must consider not only the immediate effect, but also the 

 remote contingency of the natural enemy also changing its habits 

 as a result of change of environment. 



Thus although starlings were introduced into Tasmania to keep 

 down various pests, they are now one of the biggest fruit pests we 

 have. I have noticed, however, that possibly owinsr to the existence 

 of insectivorous birds, such as swallows and martins in Tasmania, 

 it is possible here to grow cabbage, cauliflower, and other vege- 

 tables without their becoming fly-infected or blown, an experience 

 which one could only avoid by special treatment in Auckland, N.Z. 



In tliis respect I recommended the experiment of introducing 

 swallows and sand martins into New Zealand at Tauranga Experi- 

 mental Farm. Certainly the multiplication and encouragement of 

 fly catchers is of special benefit, as experience showed at Motuihi. 



With regard to flies, after trying various means of destroying 

 Mus. domestica, the common house-fly, and other varieties, I have 



