18 THE BLOWFLIES OF NortH AMERICA 
and retail outlets causes an annual financial loss to the meat 
industries as well as to the purchaser. Sums spent upon screw- 
worm remedies such as benzol and pine tar oil have not been 
estimated. Expenditures upon traps, fly papers, and other 
similar devices for use in blowfly plague alleviation are unknown. 
The cost of the labor alone to install and supervise such devices 
must be high. 
No exact total of monetary loss occasioned by blowflies can be 
ascertained. It is apparent that the annual loss caused by such 
flies is much greater than has been recognized generally. 
CONTROL OF BLOWFLIES 
The methods to be followed for the control of blowflies are 
more or less dependent upon the species involved, and a know- 
ledge of their habits and biologies is needful for exact procedure. 
However, the following general recommendations may be made. 
BLOWFLY CONTROL BY SANITATION. The practice of 
thorough sanitation in urban or rural areas is necessary to com- 
bat plagues of blowflies. These practices will also serve to miti- 
gate plagues of other household flies as well. The odors of © 
cooking foods, such as cabbage or cauliflower, may attract flies 
from considerable distances, and these flies may then remain 
in the vicinity to feed upon improperly handled garbage or 
about filthy garbage containers. Garbage containing meat scraps 
or meat products may be a constant source of blowflies during 
summer months if placed on open dumps. The proper disposal 
of meat and meat scraps by slaughter houses, butcher shops, or 
markets is a matter which should receive the constant attention — 
of public-health authorities. © 
Protection of human foods. Foods intended for human con- 
sumption should be protected from blowflies. Meat of any sort, 
whether fresh, cooked, cured, or dried, is especially attractive to 
them. Dried fish hanging in market places, particularly in 
tropical areas, may become literally covered with swarms of 
feeding blowflies. The slaughtering of animals and the distri- 
bution of meat before daylight in tropical countries is a ecom- 
mendable practice, but the manner in which such meat is after- 
ward exposed 1 in open markets and bazaars is deplorable. This 
very-ecommon procedure renders such meat accessible to every 
blowfly m the entire street or market place. Cold meats or other 
foods left: unprotected in kitchens or dining rooms where blow- 
flies may have access to them become potential sources of various 
diseases transmitted by these flies. Even fruits and vegetables 
