24 THE BLOWFLIES OF NortH AMERICA 
included, whole islands where possible, for fly control in limited 
areas cannot possibly last for long periods of time. In no single 
instance did this type of control program fail to reduce blowfly : 
populations to a near vanishing point for from six months to a 
year or more. I reported upon the first of these great control 
operations in 1945 under the title ‘‘Aerial DDT, Emergency 
Measure for Control of Mosquito-borne Epidemies.’’ | 
The residual treatment of inside walls of food-handling 
establishments with DDT is not, however, desirable. Flies 
affected by DDT residual treatments do not die until they have 
staggered, stumbled, and bumbled about, often into food. | 
MYIASIS CONTROL (Human). Infestation of human beings 
by larvae of blowflies may be prevented by personal hygiene, by 
sleeping during the day behind screens or under nets, by full 
screening of hospitals, and by the complete protection of indi- 
viduals with wounds or nasal ecatarrh. 
Early diagnosis and treatment of maggot infestations is of 
the utmost importance. Deep-seated infestations such as those 
in natural body openings may not be noticed for some time. 
Early indications are pain, local swelling, or sensations of bur- 
rowing or crawling. The presence of bloody discharges is often 
a diagnostic feature. 
Maggots should be removed by a competent physician promptly 
upon their discovery, for they may do much damage to human 
tissues within a very short time. In infestations of natural ori- 
fices, ether, chloroform, or benzol may be introduced on a pledget 
of cotton so that the larvae will be forced to breathe the fumes. 
Such an application will kill or stupefy the maggots, after which - 
they may be removed easily with blunt-tipped forceps. A second 
or third application of the anesthetic for 2 or 3 minutes may 
prove necessary for the removal of all larvae. Upon the removal 
of all maggots, antiseptics should be applied to the wounds to. 
prevent infection. 
MYIASIS CONTROL (Animal). Infestation of animals by 
serewworms or other myiasis-producing flies can be prevented. | 
Sores, cuts, or bruises on stock in pasture should be carefully - 
watched for maggot infestation. To prevent unnecessary in- 
juries in yards or stalls, nails, projecting boards, and snags- 
should be removed. Overcrowding, trampling, and rough> 
handling of animals shipped in ears or trucks should be avoided. 
The shearing of sheep and goats should be carefully done, and 
cuts should be treated every day or two until they are healed.» 
Operations such as branding, castrating, or dehorning, and the- 
birth of animals should be planned, if possible, for the cold: 
