(3) 
success, large or small, has been attained in a number of cases is 
without doubt. The classic case is of course the effect produced 
by Novius (Vedalia) cardinalis Muls. against the cottony cushion 
scale (Lcerya purchasi Mask.) in California. I have followed in a 
very general way the records of the successes attained in foreign 
eountries, including under that term, for convenience, Hawai. There 
is no doubt that not only a measure of success has been obtained in 
many istances, but that the measure has been in a few cases a very 
satisfactory one, amounting in, the California instance just cited to 
the almost complete extermination of the pestiferous insect. 
At first blush there seems to be no reason why what has been done 
in one section of the country can not be equally well done in another ; 
and why, if it has been shown that on the Pacific coast a species of 
eoccinellid is found keeping a scale insect in check, that same species 
should not do precisely the same work in the State of New Jersey. 
Vith this idea, I made my first visit to California and the Pacific 
coast in 1896; in the first place to determine whether, as against the 
San Jose scale, the coccinellids were really effective, and, second, 
whether it would be possible to acclimate these insects in New Jersey. 
A few years ago I would have said that what can be done in Cali- 
fornia can also be done in New Jersey, and that the results of experi- 
ments obtained in New Jersey were equally valid in California. The 
experience of the past few years has modified my opinion on this 
subject very materially. I am extremely reluctant nowadays to even 
advise a New York or a Pennsylvania fruit grower to make applica- 
tions based upon what I have found to be effective in New Jersey. 
In fact, I have discovered that I can not always duplicate results two 
years in succession ; that when I find an application almost completely 
effective one summer, I am as hkely to find it, under apparently 
similar conditions, absolutely ineffective the year following. Perhaps 
it does not often occur that such extreme contradictions are noted; 
but I think every working economic entomologist has seen cases at 
least similar to the one just suggested. 
I do not encourage too great hopes from importations made from 
California into New Jersey. You are probably familiar with the 
report made by me in 1597 as to the results of my investigation ; how 
I found that in the more’ southern parts of the State the pernicious 
scale was really kept in check by a coccinellid not the species which 
had been credited with the work, but by a common native form, 
Chilocorus bivulnerus Muls. I found, too, that the species that was 
most generally credited with being the check to the scale could 
searcely be found at any time, and that instead of Rhizobius lophante 
Blaisd., which is an introduced species, Scymnus marginicollis Mann. 
is really the effective form. Nevertheless I succeeded in making ar- 
rangements by which I introduced into the State of New Jersey dur- 
