62 PROTECTION OF PLANTS — 1922-23 



but one generation a year in Nova Scotia, these eggs hatching the following 

 season, as has been already indicated. 



Natural Enemies 



This study has now been carried over two entire seasons and all investi- 

 gations have shown quite clearly that the Green Apple Bug is almost entirely 

 free from the attack of predators and insect parasites. A few of the nymphs 

 are captured by ants and spiders but their great agility seems to safeguard 

 them pretty thoroughly from the attack of all predators. Egg parasites of 

 aU kinds are wholly lacking, as are insect parasite(S in the nymphal instars 

 and as a result the nymphs reach the last stage of their development practi- 

 cally unchecked. If all of these were able to develop into adults and deposit 

 eggs, an enormous increase would result; but a very important control in the 

 form of a fungous disease causes a large mortality in the last nymphal and 

 adult stages, thus bringing about a very material decraese in the number of 

 the adults before oviposition takes place. This fungus, which has proved 

 itself capable of d'^v eloping equally well in dry or wet seasons, has been of 

 inestimable value to the orchardists and is rapidly causing the Green Apple 

 Bug to disappear from the Annapolis Valley. 



Life History and Development of Empusa nov. sp. 



This organism, which proves to be a new and undescribed species of 

 Empusa, passes the winter in the resting spore stage. These spores are found 

 in the form of a dense envelope adhering to, and partially surrounding, the 

 abdomens of diseased adults, which lie hidden away under the loose bark 

 scales on the upper limbs of apple trees. 



In the spring about the time the Green Apple Bug nymphs emerge each 

 resting spore gives rise to a minute germ tube which develops into a small 

 c onidiophore, bearing on its tip a tiny conidium. In the vicinity of Wolfville 

 t he f criod of germination extends over at least forty days, which should be 

 representative of conditions throughout the Valley. 



When full}" formed, these tiny spores are shot out from under the bark 

 and float around in the air currents until they come in contract with a newly 

 emerged nymph. They then germinate and a germ tube grows into the body 

 of the insect, either through one of the spiracles or else directlj^ through the 

 integument at a point where it is thin, possibly between the body segments or 

 leg joints. Once inside the nymph, the fungus commences to grow, not in 



