44 PLATE DLV. 



dinary manner it is feldom that they extend through a whole coun- 

 try. " On the Kingfton road I traced them (fays this author) as far 

 as Putney Common, on the farther part of which, on the trees about 

 Coorabe Wood and Richmond Park, a web was not to be feen. 

 I remarked, that they were extremely numerous at the diftance of 

 about eight miles on the Uxbridge road. On the great weftern 

 road they terminated about the Star and Garter leading to Kew ; 

 from whence to Alton in Hampshire not one was vifible ; and I have 

 received undoubted information from other quarters, that the de- 

 ftiuclion they occafioned is by no means general." 



Our remarks on the partiality fhewn by thefe infects for fome ve- 

 getables m preference to others will be eaiily perceived from the 

 following ftatement : during the (ea(on mentioned (and in this they 

 are invariably conftant) they occurred on the hawthorn moft plen- 

 tifully, oak the fame, elm very plentifully, moft fruit-trees the fame, 

 blackthorn plentifully, rose-trees the fame,, and bramble the fame: 

 on the willow and poplar fcarce, and none were noticed on the 

 elder, the walnut, aili, fir, or herbaceous plants. Thus it appears, 

 that the principal injuries fuftained are in the orchard, the cater- 

 pillars deftroying the bloffoms as well as the leaves, and thereby 

 the fruit in embryo ; the lofs of the leaves merely in many other 

 trees, mould it happen in the fpring, being of fmall importance, as 

 thefe are reftored before the end of fummer. 



Thefe caterpillars have happily many enemies ; they are delec- 

 table food for moft birds, who eagerly devour them ; they are alfo 

 victims to the Ichneumon fly, which deftroys them by myriad?, and 

 it is fuppoftd the abfence of the latter, from fome unknown caufe, 

 might have contributed, for one or two feafons, to their immenfe 

 increafe. The young caterpillars are hatched early in autumn. As 

 foon as they quit the egg they begin fpinning the web, and having 

 formed a fmall one, they proceed to feed on the foliage by eating, 

 like moft other larva?, the upper furface and flefhy part of the leaf. 

 In thefe webs, which are progrefiively increafed in iize as necef- 



y fib? 



