6 
Second Report on Economic Zoology. 
over with board lids or with fine perforated zinc covers, the former in 
preference. 
Instructions being; given to the men to see they are always kept closed. 
(2) The overflow (No. 4, paragraph 2) should be either allowed to flow 
more freely away or drained off with pipes. 
(3) The small stagnant pieces of water on the borders of the Forest 
and just inside might easily be filled in with rubbish, and also the stagnant 
pieces on the Common, or the latter might be drained. 
(4) The ponds in the meadow below the Hall, and the two larger clean 
pieces of water on the Common should be treated with paraffin as soon as 
any signs of the Culex larvae are seen, and also any other pieces of 
stagnant water that cannot now be filled in. 
The method of treating with paraffin is appended. 
(5) Observations should either be made by some competent person or 
some intelligent man in the locality to find out when the larvae occur, 
and then the paraffin treatment adopted. 
Although there are several widely scattered places likely to prove 
suitable breeding-grounds for this mosquito, the cost of treatment would 
not be great, and if the presence of the larvae is noted and treatment 
carried out then in conjunction with the recommendations 1 give regard- 
ing the artificial collections of water, I see no reason why this pest should 
not be completely stamped out. 
Destruction of Culicid Larvae. 
1. The best culicicide to use is paraffin. 
2. It is best applied to pools by dipping a bundle of rags attached 
to the end of a stick into the paraffin and dabbing the surface every 
here and there so as to produce a thin film all over the water. 
3. The pools should be treated once a week during the time the 
larvae are found in the water. 
4. Do not be too sparing with the paraffin — an even thin film 
over the whole pool is necessary. This film needs to be applied to 
all the small puddles around the larger ones, as larvae may often be 
found in very small collections of water. 
I have examined the Mosquitoes taken around Higham Hall by 
Mr. Lowe and find tlie majority belong to two species, (1) the Common 
Gnat or Household Mosquito ( Culex pijnens , L.), and (2) the Mood 
Mosquito ( Culex nemorosus, L.). Both these bite, but especially the 
latter. The common gnat breeds in rain barrels, tanks, cisterns, etc., and 
can be easily destroyed ; the larvae of this species were found by Mr. Lowe 
in numbers in such places near your house. Culex nemorosus breeds in 
almost any water, even in lakes, so that probably fresh lots might come 
from the lake in the park ; the smaller pools in the forest are just the 
pools for them to breed in, and by treating them with paraffin I think 
the nuisance will be nbated. Should this not be so, the edges of the 
lake must be paraffined in still weather where the larvae occur. It would 
