PARASITES IN INSECT CONTROL—-HOWARD 415 
In a thoughtful and important paper just published in Nos. 6 
and 7 of the Revue de Zoologie Agricole for 1925, B. Trouvelot has 
listed the principal attempts made in sending beneficial insects from 
one country to another from 1873, when Riley and Planchon intro- 
duced 7'yroglyphus phylloxerae into France from the United States, 
down to the present year. Thirty-four such efforts are listed, of 
which 17 were made at a cost so slight as to be inappreciable, while 
I estimate that the others cost in the neighborhood of $150,000. 
Of the 34 attempts listed, more than half (18) have not as yet 
shown beneficial results, and the majority of these will never show 
such results. 
In this list there is no mention of many efforts, costing large 
sums of money, which have been absolutely fruitless, notably the 
world travel for many years of one of the California agents; the 
journey of two South African experts to Brazil to investigate one 
of the announced finds of the Californian; circumnavigation of the 
globe by an Australian expert, and, I fear, some of the more recent 
work of traveling agents of California, Hawaii, Italy, and the 
Bureau of Entomology at Washington. 
Wherever there is actual waste of money in parasite work, it must 
usually be laid to ignorance or incompetence. Only the best-trained 
experts must be allowed to take part. It becomes a matter of danger 
to the country in other hands. It is for this fact that the United 
States Bureau of Entomology, with its large corps of men who have 
made such work their especial study, wishes to control in a way all 
such importation work for the United States; and it is, in fact, so 
empowered by law. It is for this reason that we have charged our- 
selves with the establishment of the parasites of the European earwig 
in the Northwest, although the city of Portland is apparently willing 
and able to undertake the work. 
There are many things which will be brought out in this sym- 
posium, and many more which might be discussed to great advan- 
tage, but I can touch on only a few, although I could talk on the 
general subject all day long for several days. 
Passing over the well-known subject of hyperparasitism, we may 
well devote a few words to superparasitism or coparasitism. The 
possible introduction of too many parasites—that is, too many kinds 
of parasites—has been seriously considered by workers for a number 
of years. Beginning with the strenuous controversy between Ber- 
lese and Silvestri concerning the parasites and predators of Aula- 
caspis pentagona, and strengthened by the studies of Pemberton and 
Willard of the parasites of the Mediterranean fruit fly in Hawaii, 
the different aspects of the subject have been more or less theo- 
retically considered by several writers, notably by Thompson, by 
Wardle and Buckle, and Trouvelot in his recent papers. 
