Grand Forks herald. [volume] (Grand Forks, N.D.) 1916-1955, 1920-09-06

or more particularly for the prevention
CT their breeding. One Of the most
familiar IS the use Of petroleum, a thin
film Of which on the surface Of a still
pond will suffocatc and destroy the wig
glers. But the really effective measure.
and the only one applicable to the salt
marshes, is ditching and draining.
The marsh surface is nurmally about
one foot above the level of mean high
tide.y Ditching removes the, Sheet water
from the surface and cn,pties all the
shallow pools. Experience has proved
that the bitches should be ten inches
wide and thirty inches deep, with
smooth sides and even bottom. Where
evcr possible. they are led into creeks,
otherwise into larger outlet bitches.
Ordinarily they are dug $50 feet apart.
The work may be done with a garden
spade. but special tools for the purpose
have been developed, n of them being
n three man spade and best Of all
is the power ditcher, which cuts nearly
a mile of trench in a ten hour day.
1t is practicable so to open a salt
marsh by ditclling that all the water
will rise aud fall Will, the tide and
give the kil]iisls easy access to all parts
Of the marsh. The deeper pools, which
trenches may. not drain, harbor these
hungry minnows. In a few localities
it is found more expedient to fence the
tide out. but in such cases it is neces :
sary to provide means for introducing
and distributing the killitish through
out the bitches.
In order to- be Matched from the egg,
go through the pupa stage, and hnaNy
to assume the winged form. the salt
marsh mosquito requires a certain
amount of rcpose. 1t must have still
water, though it be only a puddle.
There is a total area of 100 900 acres.
representing the project for initial
drainage work, the completion Of which
will cost. it is estimated. about 5000, :
900. The average requirement is 500
feet of ditching per acre, and it's cost
for large areas averages two cents 9
linear foot. or Sc an acre.
When the ditching has been done,
there is the question Of maintenance
to be considered. The trench systems,
with their outlets; must bt kept in
proper, repair. The annual cost of this
is, reckoned at about forty five cents
an acre. Speaking in a general way
the business of maintenance is to b.
taken care of by the counties.
The state Of Pennsylvania, the city Of
PLiladelphia the Emergency Fleet Cor
poration and the Westinghouse Electric
Co. recently undertook to stop thu
breeding OF mosquitoes<in South Phfla-
dclphia and the northeast part of Della
ware county: In a year they jointly
spent $260.O00 on tho work, which will
be continued until, by systematic ditch
ing aud draining, the plague is sup.
pressed. W
Jersey City, Newark, Elizabeth ant
|, Paterson, not To mention other towns
!. aul the city Of New York suffered from
swarms Of mosquitoes Matched on TIL
salt marshes known as the Hackensacl
Meadows, Asfew years ag6 tlieysstarte'
, in to, get rid Of the nuisance by ditchin''
and draining. with most satisfactor,
\ results. Huge factories are already DC
. cupying part II the area freed from tn
. amiction, anda consequent rise In tn
value Of real estate amounts to man
times the costsof the t.clean up.
! Inrdustries cannot fiourislswhers wor
. people are t~orlnsnted BY nlcsqaitcesssa
b some peoplH do not mind inosaniit
Il bites much others are very distressing
i III peisoned ) shems Why this y |
nobody knows: iii. Just Z matter \
physical idiosyncrasy.