INSECTS AND VE11MES. 347 



whole forests and districts. At this season they leave their 

 aurelia, 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 Phalcena. The aurelia of this moth is 

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

 the tree, which is rolled round it, and secured at the end a 

 by a web, to prevent the maggot from falling out. 1 



EPHEMERA CAUDA TKIESTA MAY FLY. 



JUNE 10, 1771. Myriads of May flies appear for the first 

 time on the Alresford stream. The air was crowded with 

 them, and the surface of the water covered. Large trouts 

 sucked them in as they lay struggling on the surface of the 

 stream, unable to rise till their wings were dried. 



This appearance reconciled me in some measure to the 

 wonderful account that Scopoli gives of the quantities em erg* 

 ing from the rivers of Carniola. Their motions are very 

 peculiar, up and down for many yards almost in a perpendi- 

 cular line. 2 



SPHINX OCELLATA. 



A VAST insect appears after it is dusk, flying with a humming 

 noise, and inserting its tongue into the bloom of the honey- 



1 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 

 exuviae or remains of the chrysalis, from whence I suppose the moths 

 had issued, and whose caterpillar had eaten the leaves. MARKWICK. 



2 I once saw a swarm of these insects playing up and down over the 

 surface of a pond in Denn Park, exactly in the manner described by 

 this accurate naturalist. It was late in the evening of a warm summer's 

 day when I observed them. MARKWICK. 



