110 PROTECTION OF PLAN'TS. 1916-17 



A FUNGUS CLUB ATTACKING THE OAK SCALE 



P. L Bryce, Macdonald College 



The soft scales or Lecaniums attack shade, fruit and forest trees, as 

 well as various greenhouse palms, crotons, ferns and begonias . The Euro- 

 pean fruit scale or New York plum scale and the terrapin scale have proved 

 serious, though usually local, pests in favorable seasons. 



The Lecaniums have a soft shield or oval-shaped body protected by a 

 scaly covering of various shapes. At first active, the insect soon after hatch- 

 ing settles down to feed and usually loses legs, eyes and feelers. On the 

 under side of the body the head carries a long piercing beak, or sucking mouth 

 like a six-lash whip. 



The tip of the beak is sharp and saw-like, and when a favorable place 

 for feeding is found the scale thrusts the beak into the juicy tissues of the 

 host plant. The sap is sucked out and the plant weakened, or is poisoned 

 by the attack. Leaves, twigs, and small stems are attacked. 



Young scales produce a sweet sticky honeydew, which falls to the ground 

 below. The sooty black fungus that grows on the honeydew gives infested 

 plants a dirty unhealthy appearance. 



When mature, the male insect develops a pair of wings, crawls out from 

 under the scale, and is active. In spring, the sedentary female lays from a 

 few to 2,000 eggs under the scale, where they may be found filling her 

 shrivelled body. 



In the fall of 1916, a swamp white oak was noticed near Ste. Anne de 

 Bellevue infested by a soft scale, closely resembling in gross and microscopic 

 appearance the Oak scale (Lecanium qiiercifex Fitch). Many of the scales 

 showed signs of a fungus which had thrived upon the body of the scale, 

 fruited, and produced spore-bearing branches. The scales were covered, 

 some of them, with these tiny club-like stromata or projections, each 1.75- 

 2.0 mm. high, with a head to the club 0.3 mm. thick, rather obovate, brown- 

 ish-gray, rising on a very short handle or stripe, ashen gray in color. The 

 stromata or clubs grow, some from the sides, but mainly from the dull 

 black dorsal surface of the scale. The fungus in hand sections showed no 

 perithecia or spore cups. The description agrees with that of the Gray 

 Coccus Club (Cordyceps clavulata Schw.) 



It is uncertain whether this Cordyceps is a fungus parasitic on living, 

 or saprophytic on dead scales. Only dead scales show the fungus, and it 



