The evening times., 1900-07-18
Oil TO KILL MOSQUITOES
Spread on the Surface Of Water, a
Prevents Propagation.

Prevents Propagation.
BALTIMORE, July 1S.-In addition 10
the hot weather residents in many sec
tions of this city have another discomfort
to face in the presence Of swarms Of mos
quitoes- These insect pests Rshe life less
worth living than il might be il they were
removed.
Some spasmodic efforts are made 10 drive
the mosquitoes out OF homes they have
invaded or to keep them from entering by
means Of screens In some homes the only
relief is found under canopy which COW
ers the bed and which has to be caI fIlly
explored each night 70 see that no1 2 Of
the lively seekers for human blood have
secreted themselves in a rold OF the net
ting in readiness Tor their nightly foray
upon their sleeping victim.
EntOmOlogists Of the Agricultural De-
partment say that these methods are
wrOng-a sort OF locking the stable door
after the horse is stolen. and that the true
method OF extinction is to prevent the
propagation Of the pests In order to IN
derstand how this method acts it is Eeces-
sary TO recall some Of the characteristics
Of the insect.
The mosquito lays eggs in the early
morning hours in masses Of from 200 TO 4Ge
4 from each female These are deposited in
still water. Observations have shown that
the eggs hatch as s0on as sixteen hours
and probably sooner. The larvae are ex-
tremely active at birth. but they must
have air. and in that lies the secret OF ex-
termination To get air they must wrig-
gle their way 10 the surface OF the water
in order 10 breathe. After seven or eight
days the larva transforms 20 pupa, in
which stage the insect is lighter than the
water and remains on the surface without
effort.
The fact says DR.. L. o. Howard.
chief entomologist Of the Department OF
Agriculture, that the larvae, after they
are once below the surface OF the water,
sink rather than rise. accounts for the
death of many individuals II they be
come sick or weak or for any reason are
unable 70 exert sufficient muscular force 70
wriggle TO the surface al frequent inter-
walls they will actually drown This fact
also explains the efficacy Of the remedial
treatment which causes the surface Of the
water 10 become covered with hlm OF
oil Of any kind Aside from the actual
insecticide effect OF the oil. the larvae
drown from not being able 20 reach the
air.
Generally the adult insect issues from
the pupa that i two days old This gives
the miEimum generation as ten days The
layiTg OF eggs takes place in three or four
days after the emergeuce CT the adult
insect. This accounts for the fact that
swarms OF mosquitoes may develop upon
occasion IL surface pools CT rain water
which may dry up entirely IN the course Of
two weeks. OF in a chance bucket Of water
left undisturbed for that length Of time
That mosquitoes can stand cold IS shown
by the fact that they have been found hi
bernating in cold cellars in Northern cities
They have been observed in cold climates
IN the midst Of suOwstorns-
Aside from their fCE5Eess for warm
blood. mosquitoes have been noticed Is
having a f1uduess for molasses and one
was observed drinking beer
The three main preventive measures ad-
vocated for getting rid Of mosquitoes are
the draining OF breeding places. the intro
duction Of small fish into fshless breeding
places. and the treatment Of such pools
with kerosene oil Anyone OF these is prom
ised 10 be efhcacious by entomOlogists. The
draining OF the swamps and fats OF the
Potomac about Washington have been OBJ
served TO largely reduce the number OF
mosquitoes in that city Small fish ike
carp have been tried in various places. the
fish eating the larvae. IN small Texas
town It was found that other food was nee
essary for the fish, which is there called
perch. so the people adopted a fy trap
20 catch flies in their houses These flies
are fed 10 the fish. which thus serve the
double purpose Of Riding The place OF TWO
household pests.
But the plan OF coating saltwater sur
faces with kerosene oil is said 10 be most
applicable in Baltimore. where IL has been
tested. a report Of the chronological di-
vision states;
In many houses in Baltimore the sew
"a H-1f fuG int n~S Sfv4L- IN no hr ri
yard. and thence in some cases into sew
ers. and in other cases Is pumped out pc
riodically- The mosquitoes which breed IN
the stagnant contents OF these sinks have
free eEress into the open air back Of the
houses Kerosene has been tried and two
treatments seem 10 diminish the numbers
Of the pest in that particular house But
without concerted action Of all the house
holders in a given block no great amount
Of good could be accomplished With such
concerted action. howevC.. there seems 70
be no reason why the mosquito plague
could not be greatly diminished in many. II
not most. parts Of Baltimore al a very
small expense"
Il has been found that about one ounce
Il oil sufices for fifteen square feet Of wa
ter surface. and ordinarily the application
would not be renewed for month. The oil
has been used succcs ssfully IN the surface
Of tanks Of drinking water from watch TIE
water was removed by means Of pipes az
the bottom Here there is relief for mos
quito bothered residents.