ENTOMOLOGY

479lSANITARY ENTOMOLOGYSUMMARYThroughout this course of lectures my main object has been to showthe diverse manner in which insects may cause patliological conditions ormay transmit pathogenic organisms. Unquestionably the majority ofspecies which carry disease organisms have not yet been recorded in thisrBle. In the past we have attempted to minimize the possible rBle of theinsect as a carrier of 'disease. In the future it would be wise to take thestand that insect transmission of a disease should be one of the firstmethods of transmission investigated and that the investigation shoqldbe carried out on logical lines suggested by the habits of the insectsconcerned. It is to be regretted that a large part of the study of insecttransmission of disease has been aimed at proving or denying transmissionby means of the bite of the insect. We have seen from the evidencepresented that a large proportion of the cases of insect transmission arenot by the bite but rather through the feces of the insect. We maytherefore consider that many of the conclusions that insects are not involvedin the transmission of certain diseases are unwarranted and thatthe cases should be reopened and studied more scientifically.Any insect which visits excreta or which visits food or the person ofman or animals is to be considered a suspicious object in a diseasetransmission inquiry. Naturany we will look to the blood-suckers asthe first means of transmitting disease of which the organism is found inthe blood, but when the diseases are of the intestinal or genital organs,we are more apt to find that the disease is carried by insects which becomecontaminated by contact with infected excretions. Another unexploredfield of study is the determination of toxins in foods, produced by contaminationof insects feeding therein.If through this series of lectures we have succeeded in interesting afew investigators to look into the subject of transmission of certaindiseases more.thoroughly, we shall feel that we have been'successful in ourefforts.