456 OBSERVATIONS ON 



foetus in quiet; hence the sexes are found separate, except 

 where generation is going on. From the multitude of minute 

 young of all gradations of sizes, these insects seem without 

 doubt to be viviparous. WHITE. 



PHAL^NA QUERCUS. 



Most of our oaks are naked of leaves, and even the Holt in 

 general, having been ravaged by the caterpillars of a small 

 phalcena which is of a pale yellow colour. These insects, 

 though a feeble race, yet, from their infinite numbers, are of 

 wonderful effect, being able to destroy the foliage of whole 

 forests and districts. At this season they leave their aurelice, 

 and issue forth in their fly-state, swarming and covering the 

 trees and hedges. 



In a. field at Greatham, I saw a flight of swifts busied in 

 catching their prey near the ground ; and found they were 

 hawking after these phalcence. The aurelia of this moth is 

 shining and as black as jet ; and lies wrapped up in a leaf of 

 the tree, which is rolled round it, and secured at the ends by 

 a web, to prevent the maggot from falling out. WHITE. 



I suspect that the insect here meant is not the phalcena 

 quercus, but the phalcena viridata, concerning which, I find 

 the following note in my Naturalist's Calendar for the year 

 1785. 



About this time, and for a few days last past, I observed 

 the leaves of almost all the oak-trees in Denn copse to be 

 eaten and destroyed, and, on examining more narrowly, saw 

 an infinite number of small beautiful pale green moths flying 

 about the trees ; the leaves of which that were not quite 

 destroyed were curled up, and withinside were the exuvice or 

 remains of the chrysalis, from whence I suppose the moths 

 had issued, and whose caterpillar had eaten the leaves. 

 MARKWICK. 



