A Study in Insect Parasitism

For a number of years the writer has been interested in insect parasitism and its relation to the control of injurious insects. Occasional notes have been made on different species of parasites and considerable interesting data has been obtained concerning the parasites of one of our common Iowa insects, the tomato-worm, Phlegethontius sexta (Johanssen), sometimes called the tobacco worm or the southern tobacco worm. It is with certain parasites of this particular insect with which this paper has to deal