affecting the Clover-cro-ps and Pasture-lands. 65 



thus the nurseries for the deposition of the eggs and the nourish- 

 ment of the larvae, it is naturally to be expected that a crop im- 

 mediately succeeding fresh broken-up pasture-land would fall a 

 sacrifice to the inroads of insects, unless special care be taken to 

 eradicate the enemy by paring and burning before the corn or 

 other crops be sown. 



It also becomes more difficult to obtain good yielding crops in 

 a mixed tenure of corn and grass-land, or in the neighbourhood of 

 marshes, pastures, and grass-lands, as the insects bred there 

 migrate to the adjoining arable lands, and often find food more 

 agreeable to them than that which they have deserted, so that 

 the click-beetles, moths, and crane-flies depositing their eggs, 

 the farmer soon finds his land infested by wireworms, surface- 

 grubs, and leather-jackets, to which his turnips, beet, and corn 

 fall a sacrifice. 



To make the farmer acquainted with the hosts of insects which 

 find a home in pasture-land would occupy volumes ; it will, 

 however, answer every purpose connected with the object of these 

 reports, if we lay before him the most important species which 

 feed on the seeds, flowers, and foliage, those which live upon or 

 in the stems, and others which consume the roots. 



The tribe of insects which we shall first notice is the family 

 of Ajj/iides, or plant-lice. It is a confirmation of my views on 

 this subject to find that the plant-lice which infest the wheat are 

 generated on the panicles of grasses, as I learn from Mr. F. 

 Walker, who has kindly communicated the following observa- 

 tions, and descriptions of two species. 



25. Aphis Avex^, Fair. A, Granaria, Kirhij. A. Hordei, 

 Kyher. A. Cerealis, Kaltenhach. 



Feeds on Secale cereale, Triticum astivum, Avena sativa, Dan- 

 thonia strigosa, Hordeum vulgare, II. murinum, Bromus mollis, 

 B. secalinus, Dactylis (jlomerata, Holcns lanafus, Glyceriajluitans, 

 Poa annua, and other grasses, and Pohjgonuni j)ersicaria. 



Wingless female. — Colour red, green, brown, or yellow. Front 

 convex in the middle, and with a distinct lobe on each side. 

 Antenna? black, nearly as long or longer than the body. Ab- 

 dominal tubes black, nearly one-fourth of the length of the body. 

 Knees, tarsi, and tips of the tibia^, black. 



Winged female. — Brown, rarely green. Abdomen with a rov/ 

 of black dots on each side ; tip yellow ; stigma brown ; wings 

 vitreous ; veins pale yellow. 



2G. Aphis dirhoda, Walk. Annals Nat. Hist. 



Feeds on Rosa centifolia, R. canina, and R. eglantina, and 

 migrates in the summer to different species of corn and grasses, 

 VOL. XV III. F 



