394 ENTOMOLOGY 
to escape observation. Regarded as a direct tax of ten cents 
upon the dollar, however, this loss becomes impressive. \Web- 
ster says: “It costs the American farmer more to feed his 
insect foes than it does to educate his children.”’ The average 
annual damage done by insects to crops in the United States 
was conservatively estimated by Walsh and Riley to be $300,- 
000,000—or about $50 for each farm. “ A recent estimate by 
experts put the yearly loss from forest insect depredations at 
not less than $100,000,000. The common schools of the coun- 
try cost in 1902 the sum of $235,000,000, and all higher insti- 
tutions of learning cost less than $50,000,000, making the total 
cost of education in the United States considerably less than 
the farmers lost from insect ravages. “Thus it would be within 
the statistical truth to make a still more startling statement 
than Webster’s, and say, that it costs American farmers more 
to feed their insect foes than it does to maintain the whole 
system of education for everybody’s children. 
“ Furthermore, the yearly losses from insect ravages aggre- 
gate nearly twice as much as it costs to maintain our army and 
navy; more than twice the loss by fire; twice the capital in- 
vested in manufacturing agricultural implements; and nearly 
three times the estimated value of the products of all the fruit 
orchards, vineyards, and small fruit farms in the country.” 
(Slingerland. ) 
Though most of the parasites of domestic animals are 
merely annoyances, some inflict serious or even fatal injury, 
as has been said. The gad flies persecute horses and cattle; 
the maggots of a bot fly grow in the frontal sinuses of sheep, 
causing vertigo and often death; another bot fly develops in 
the stomach of the horse, enfeebling the animal. The worst 
of the bot flies, however, is Hypoderma lineata, the ox-warble, 
which not only impairs the beef but damages the hide by its 
perforations; the loss from this insect for one period of six 
months (Chicago, 1889) was conservatively estimated as 
$3,336,565, of which $667,513 represented the injury to hides. 
All sorts of food stuffs are attacked by insects, particularly 
