234 FOREST ENTOMOLOGY. 



found at all. So far I have not been able to ascertain the approxi- 

 mate date at which the larv^ emerge from the eggs and betake them- 

 selves to the opening buds, but they do not assert themselves on the 

 foliage until well on the middle of May. By this time the leaves are 

 well developed, and thus afford plenty of food for the larvae, which 

 live gregariously, and spin a veil-like web over the colony. They are 

 full fed by the middle of June, and the pupal stage completes their 

 life-history. 



As this species is in many cases very injurious, and as its host-plant, 

 the bird-cherry or hackberry, has some claims as an ornamental tree, 

 on account of its beautiful white flowers, it would be well in very bad 

 cases to adopt some remedial measures. It is obvious that we could 

 only apply remedial measures in its larval and pupal stages. 



As regards checking the larvte, they may be (1) shaken down from 

 the trees during the day on to a sheet, or (2) hand-picked by cutting 

 off the web containing the larvse, or (3) they may be sprayed with a 

 paraffin emulsion. With regard to the last method, the following 

 note is taken from the Board of Agriculture leaflet, No. 65 : — 



" The Board know of one case in Perthshire where, in an extremely 

 severe infestation, the proprietor, dissatisfied with the result of a 

 paraffin spray, made up a strong solution of an arsenical sheep-dip, and 

 by this means killed thousands of caterpillars. The caterpillars that 

 had not been killed, or which on disturbance had let themselves down 

 from the web by their threads, collected at the foot of the trees, and 

 were easily destroyed. Great care, however, had to be exercised, as 

 any leaves touched by the material turned black and dropped off." 



With regard to checking the pest in the pupal stage, this can best 

 be done by simply cutting off the webs when they are in the cocoon 

 stage ; but as this stage is a comparatively short one (about ten days 

 or a fortnight), no time would have to be lost in order to make it 

 effectual. 



Prays curtisellus, Don. (Ash-bud Moth). 



This species seems to entirely confine itself to one food-plant — viz., 

 the common ash (Fraxinus excelsior), and is certainly very injurious 

 indeed to plants in the nursery-lines from three to six years of age. 

 It attacks the terminal bud, and thus causes the young ash to fork, — 

 a feature we do not by any means wish to see in young ash plants. 



