6 Oklahoma Agricultural Experiment Station 



They were brought into the insectary the 1st of March and less 

 than half of them revived and lived. An interesting fact was 

 here discovered; within fifteen to thirty minutes after being 

 brought in from the cold to a temperature of 60 F., or above, 

 the hibernating forms would be thoroughly active, and when 

 placed on the leaves of the host tree would go to the under side at 

 once and begin feeding. Owing to the milder winters in Okla- 

 homa, a greater percentage are enabled to live till spring in well 

 protected places and, together with the longer season of warm 

 weather, they can accomplish very much more destruction than 

 farther north and east, where the growing season is short. 



The hibernating forms, with the approach of warm weather, 

 will come out especially on bright, sunshiny days and swarm 

 about over the trees, but on a cold day they again seek cover. By 

 the time the trees are well in leaf they have ascended to the fo- 

 liage and are feeding. About ten days are spent in feeding and 

 mating before the females begin ovipositing. 



Egg Laying 



The eggs are laid along the larger ribs, the female seeming to 

 prefer the forks of the ribs where she thrusts the egg, gluing it to 

 the leaf surface and leaving it partially covered by the leaf fuzz. 

 The eggs may be laid singly or hi groups of as many as ten. Less 

 frequently the eggs are deposited in larger, irregular patches on 

 the leaf away from the ribs. Each egg is placed on end, usually 

 erect, but frequently inclined to one side. The act of depositing 

 an egg requires about two minutes, during which time the female 

 has the ovipositor thrust forward against the leaf tissue, the 

 wings are slightly spread and braced against the leaf as she leans 

 back on them, they forming as it were, with the body and legs, a 

 tripod for support while she places the egg and covers it with the 

 sticky secretion. This gluey substance is spread over the chorion 

 and" in some instances is so profuse as to partially bury the egg. 

 The females frequently seem to have an overabundance secreted 

 which they exude in small drops when not depositing eggs. 



The number of eggs a female will lay has not been determined 

 definitely. The experiments I began in the insectary in early 

 March this year have not had sufficient time to determine this 

 point, as there are still several females ovipositing. One female 

 began depositing eggs on March 18 and had laid a total of 157 

 eggs when lost in transfer to fresh leaves. Another began de- 

 positing eggs March 18 and had laid 284 eggs up to June 9, when 

 she died after being transferred a distance of several hundred 

 miles. An interesting fact was noted in connection with the num- 

 ber of eggs an individual female will lay. The total number for 

 one female for one day rarely exceeds fifteen, usually from seven 

 to ten, and every other day this number is reduced by about half. 



