208 MALCOLM E. MACGREGOR. 



It was observed in the laboratory that the " bite " of F inlay a geniculata is 

 distinct^ painful. The proboscis is large and the initial prick of the " bite " is 

 sharp, but unlike the usual conditions when other mosquitos bite (a painless period 

 following the initial prick when once the insect has got the proboscis well embedded 

 in the tissues and has begun to feed), the initial prick from Finlaya geniculata is 

 followed by a burning sensation, which continues and increases while the insect 

 feeds ; so much so that a good deal of will-power has to be exercised against the 

 impulse to jerk the mosquito off. The subsequent effects of the " bite " are not, 

 however, more serious than the usual effects of a mosquito bite. 



Ochleroiatus caspius. 



Normal conditions. — As larvae and pupae ; found in numbers in a woodland 

 pool near Ockham. As adults ; not observed under natural conditions, but several 

 bred out from larvae in the laboratory. 



Conditions during drought. — As larvae and pupae ; unobtainable ; pool com- 

 pletely dried up since last May. As adults ; unobtainable. 



Ochlerotatus nemorosus. 



Normal conditions. — As larvae and pupae ; abundant in woodland pools and 

 streams. As adults ; very large numbers obtainable in the woods, where, particularly 

 in the afternoons, they attack so persistently that there is no peace to be had. 



Conditions during drought.— Xs larvae and pupae ; unobtainable since the wood- 

 land pools dried up in May. As adults ; unobtataable since about the middle of 

 June, when it was found that even in the afternoons one might frequent the woods 

 in peace, unmolested by a single mosquito — a state of affairs very different from 

 what obtained during the whole of the summer months last year. 



Ochlerotatus waterhousei. 



Normal conditions. — As larvae and pupae ; numerous in certain woodland 

 pools. As adults ; numerous in the woods where, associated with Ochlerotatus 

 nemorosus, they persistently attack human beings, particularly in the afternoons. 



Conditions during drought. — As larvae and pupae ; unobtainable since end of 

 May. As adults ; unobtainable since May. 



Theobaldia annulaia. 



Normal conditions. — As larvae and pupae ; numerous in certain wayside ditches 

 and in rain-water barrels. As adults ; common in stables and outhouses, though 

 never numerous. 



Conditions during drought. — As larvae and pupae ; unobtainable. As adults ; 

 a few still obtainable in pigsties in association with Anopheles maculipennis . 



From the foregoing records it will be seen that drought tends to affect the 

 mosquito population of an area adversely, decreasing the normal breeding-places, 

 and in some instances, in the case of particular species, causing the normal breeding- 

 places to disappear entirely. This is true for such species as Anopheles plumheus, 

 Finlaya geniculata, Ochlerotatus caspius, Ochlerotatus nemorosus and Ochlerotatus 

 waterhousei . It will be interesting, therefore, to see whether these species will be 



