64 PROTECTION OF PLANTS — 1922-23 



Apparently hyphal bodies from adults infected later in the season are 

 quite similar in size and shape to those found in the nymphs in the spring, 

 for careful comparisons were made and no differences could be found. 



Growth of the hyphal bodies goes on until the abdomen of the host becomes 

 completely filled. But now, instead of conidiophores being formed, resting 

 spores are produced. This is done in a rather remarkable way. Up to this 

 time the hyphal bodies had been very irregular in shape, varying from rounded 

 or oval forms through all gradations to the most bizarre structures, many of 

 which had long protuberances, giving them more or less of an amoeboid 

 form. At this stage, however, a change takes place; the hyphal bodies become 

 less irregular and more rounded in form and the contained protoplasm grows 

 denser and to a large extent loses its vacuoles. Each hyphal body gives rise 

 to a stout germ tube which gradually increases in length and finally grows 

 through the integuments of the insect. During this growth the contents of the 

 old hyphal body migrates into the tube and follows the growing point so that 

 when the fungus bursts through the integument, all the protoplasm is collected 

 at the tip. This apical portion now begins to swell and soon a rounded, globose 

 body forms into which all the contents of the tube flows. The walls of this 

 structure gradually thicken and in this way the renting spores are formed 

 outside the body of the insect, though really adhering quite closely to it. As 

 far as can be learned, these spores are asexually formed and hence are azygos- 

 pores. 



About the time the hyphal bodies are commencing to lose their irregular 

 form, the adults become very restless and wander over the tress in search of 

 a place in which to hide. They soon crawl away out of sight under some loose 

 piece of bark and there die very quickly. After the death of the host the fungus 

 goes on developing until the resting spores are formed, by which means the 

 disease is carried over the winter. 



Artificial Spread. 



As has already been started, the main object of this study on the natural 

 control of the Green Apple Bug was first to find out what parasites were attack- 

 • ng this insect and then to make every effort to increase their effectiveness. 



With this end in view, a detailed study of this new Empusa was made 

 both in the laboratory and the field, to see if it was not possible to make the 

 disease more generally useful in checking outbreaks and to find out whether 

 it was possible or not to spread it artificially into localities where it was not 

 already present. 



In the laboratory every effort was made to grow the fungus on artificia 

 media but without results. Resting spores, primary and secondary conidia, 



