REPORT OF THE SOCIETY 63 



the usual manner by means of hyphal threads, but by a peculiar budding process 

 in which socalled hyphaj bodies are produced. These hj^phal bodies are com- 

 paratively large, irregular fragments of mycelium, which at first float around 

 in the blood of the insect where they rapidly increase in size. 



Strangely enough, the fungus does not penetrate the thorax, for even when 

 fully mature it still confines itself wholly to the abdomen. Just how long 

 it takes the fungus to develop has not been learned but gradually the abdominal 

 tissues begin to disappear, due to the action of the disease, and the number 

 of hyphal bodies become proportionately greater. This increase goes on until 

 the abdomen commences to swell and when development has progressed some- 

 what further, the whole dorsum bursts open. 



Before this takes place, however, a change occurs within the insect. The 

 hyphal bodies, instead of growing in their customary manner by budding, 

 each send out a very stout tube which grows rapidh^ upward toward the back, 

 of the insect and develops into a large club-shaped conidiophore. Hundreds 

 of these are produced in a single insect, so that when the dorsum ruptures 

 a flat, continuous layer is exposed which is formed by the tips of these uprightly 

 gr.Qwing conidiophores. This layer is in turn covered by a layer of hyalin 

 mucilaginous material, closely resembling protoplasm. 



At this point in the development of the fungus the majority of the Green 

 Apple Bugs have reached the adult stage, although a few are still in the last 

 nymphal instar, and as a result, most of the dorsally ruptured insects are winged 

 forms. Due to the fact that the fungus has confined itself to the abdomen, 

 the thoracic muscles of the diseased insects are still quite capable of functioning. 

 As a result, the dorsally ruptured insects are able to move about the foliage 

 quite easily and it is not an uncommon sight to see a nymph or adult walking 

 over the infested trees trailing behind it a ruptured and frightfully mutilated 

 abdomen. This retained power of locomotion helps greatly in scattering the 

 spores and spreading the disease more widely. 



When mature, the conidia are shot off into the air, each being surrounded 

 by a mass of mucilaginous material which no doubt serves the dual purpose 

 of protecting the spores from drying as well as aiding them in sticking to any 

 surface with which they come in contact. If they a hght on an unfavorable 

 situation, secondary conidia are produced which are smaller and more oval 

 than the primary ones and are in turn shot off into the air. 



If the conidia alight on an adult Green x\pple Bug, germination takes 

 place and a germ tube grows into the })ody of the insect in the manner described. 

 Up to a certain point the development of the fungus in this stage is quite similar 

 to that found in the nymphs in the early part of the season. Hyphal bodies 

 appear and grow freely in the abdomen of the host though in no other part,- 

 increasing in size and number very rapidly. 



