February, ’24] 
RUGGLES: PIONEERING IN ENTOMOLOGY 
39 
mologist whether systematist or morphologist as long as he was identi¬ 
fied with entomology was called more and more into consultation on 
problems relating to insects of economic importance. This was be¬ 
cause he was the only entomologist of any kind to be consulted. More 
and more this type of man was called upon until the gradual evolution 
of the economic entomologist was attained. 
In this country Harris was undoubtedly the first real economic ento¬ 
mologist. His interests primarily were with economic forms. His 
writings abound with excellent observations on the insect under con¬ 
sideration and with sound practical common sense methods of control. 
His style has been followed by many workers who came after him, all 
being imbued with the idea of producing as Fernald called it “the 
rational methods of insect control,” that is, methods based on the 
knowledge of the life history of the species under consideration. The 
man with the most ingenuity in devising schemes of destruction ob¬ 
tained the public applause and gratitude. A further step in the study 
came when still more attention was paid to the details of the life history 
of the insect. The more complete the knowledge of the life history, 
the more facts were obtained upon which to base an appropriate method 
of control. Thus with insecticides coming more and more into use the 
insect could be struck at a vulnerable point culminating in its sub¬ 
jection. The “biological age” as Dr. Howard calls it is very applicable 
to this period. A great many papers could be cited to illustrate this 
method but perhaps the best are those by the late Professor Slingerland. 
These were marvels of accuracy and acumen in giving details hitherto 
not known. 
The use of insecticides has led to a side issue that has assumed enor¬ 
mous proportions. Many of the later entomologists even before 
thoroughly studying the life of the insect began experimenting with in¬ 
secticides for the control of the insect in question. An enormous field 
has opened up here for the entomologist but it must of necessity be 
primarily a chemistry field. It is not well for the entomologist to lose 
sight of the insect. The insect is primary not secondary. Not all 
insects can be controlled by insecticides and the sooner we learn that 
fact the better. In experimenting with insecticides often one experi¬ 
menter will get a result diametrically opposed to another worker in 
another state. The reason evidently is that the factors which enter into 
the problem have not all been taken into consideration. Temperature, 
moisture, wind velocity and probably a number of other factors have not 
