OAK LEAF-EOLLEE MOTH. 239 



abont half an inch long. They have the power of rolling the 

 tip of the leaf and spinning it together into a cylinder (as figured, 

 p. 238), within which, when full-fed, they turn to chrysalids ; 

 but meanwhile, on alarm or as matter of choice, they let 

 themselves down by scores or hundreds by means of silken 

 threads, for about seven or eight feet, and sway about as the 

 wind may waft them beneath the infested boughs, catching on 

 any passing object, being also a prey to many kinds of birds ; 

 but, if nothing else happens, they crawl presently back again, 

 each up its own line to the bough. When full-fed — that is, 

 towards the end of May — they turn to chrysalids either in 

 tubes, which they have formed by rolling up the tip of the 

 leaf and spinning it with threads into a kind of cylinder, or, 

 if leafage fails them, to roll up or spin together, they wander 

 away and turn to brown chrysalids in crannies of the bark of 

 the trunks or boughs. 



The moth, which appears towards the end of June, is about 

 an inch in the expanse of the fore wings, with the head, body 

 between the wings, and fore wings, of a light green ; the hind 

 wings are brownish or silver grey, and the fringes of the 

 wings, as well as a line on the front edge of the foremost pair, 

 are whitish. 



Pkevention and Eemedies. — From the circumstance of the 

 eggs of this moth being so small as not to be observable on 

 the tree, and also from the caterpillar attack (which some- 

 times extends over miles of woodland) occurring at irregular 

 intervals without any previous signs to give warning of its 

 approach, it appears impossible, as far as is known at present, 

 to apply any preventive measure of general service, excepting 

 such as may be found in the encouragement of the wild 

 birds. 



In a very severe attack on the Oaks in 1827 it was observed 

 that the Willow Wrens and Whitethroats were useful in 

 clearing the caterpillars ; the Chaffinch also ; and the House 

 Sparrows ''were indefatigable in search of them"; and 

 poultry searched under the trees for such as fell to the 

 ground (' Mem. Lit. and Phil. Soc.,' Manchester, 2nd Series, 

 vol. v.). Piooks, Jackdaws, Thrushes, Starlings, Titmice, Nut- 

 hatches, and Woodpeckers, are said to be of use in the matter ; 

 also Piooks and Jackdaws have been especially observed as 

 Hocking to the infested trees, and a second crop of leafage to 

 be soon afterwards established. In a very bad attack of this 

 Leaf-roller Caterpillar to the Oak woods at Tullamore, King's 

 County, Ireland, in 1881, Mr. A.Henderson, writing from the 

 spot, mentioned that they swarmed in thousands in every 

 direction and exposure, and had it not been for the timely 



