INSECTS. 



worm, the plant lice, and the differ- 

 ent species of cranc-Uy. 



" Wheat, in every state, is subject 

 to many insect depredators. Mr. 

 Marsham describes a small grub 

 which eats into the young plant about 

 an inch below its surface, devours the 

 central part, and thus causes its im- 

 mediate death. At a later period this 

 graia is attacked by a fly nearly re- 

 lated to the Mosilliis arcuatus of La- 

 treille. It makes a lodgement in the 

 heart of the principal stem just above 

 the root, which stem it invariably 

 destroys, giving the crop at Jirst a 

 most unpromising appearance. M'hen 

 the wheat blossoms, it becomes ex- 

 posed to the attack of a small or- 

 ange-coloured gnat, which deposites 

 its eggs in the centre of the flower. 

 The weevil is destructive to wheat 

 when in the granary, where it feeds 

 both in the larva and perfect state. 



" Rye is subject to the attacks of a 

 small fly {Musca pumilionis), which 

 introduces its eggs into the heart of 

 the shoots, and occasions a loss of 

 from eight to fourteen plants in a 

 square of two feet. No remedy has 

 yet been proposed for this pest, which, 

 if not extensive, may be checked by 

 plucking the injured cars and burn- 

 ing them. 



" Barley, besides other insect foes, 

 has one peculiar to itself, in the shape 

 of a small moth {Tinea hordci, K.). 

 This fly deposites from 20 to 30 eggs 

 on a single grain ; when hatched, 

 each of the larva; disperses, and, se- 

 lecting a grain for itself, enters from 

 without, and lies totally concealed. 

 Should these moths be observed in a 

 granary, the injury may be stopped 

 by carefully covering the grain, leav- 

 ing a few handfuls exposed; upon 

 these the moths will deposite their 

 eggs, and by roasting or destroying 

 this small quantity, the rest may be 

 saved from infection. 



" Oats are subject to few diseases ; 

 but, like all other grain, the plants 

 are liable to be destroyed by that uni- 

 versal devastator, the wire-worm, of 

 which a more particular account will 

 be found in treating of insects uni- 

 versally injurious to vegetables. The 

 N N 2 



chinch bug is often very injurious in 

 the South. 



"The diseases of peas are mil- 

 dew and blight, but these are only oc- 

 casional ; its insect enemies, howev- 

 er, are formidable ; the principal of 

 these is the plant louse (Aphis), one 

 species of which is peculiar to this 

 plant. Beans are exposed to the 

 same injury from another species of 

 aphis of a black colour, which begins 

 at the top of the plant, and multiplies 

 downward. In both cases the most 

 effectual remedy is to top the plants 

 at an early period of the infection, 

 and burn the parts so gathered ; this 

 plan is likewise advantageous, as it 

 improves both the quality and quan- 

 tity of the crop. The earlier pease 

 are sown, the belter chance they 

 stand of escaping this pest ; or if a 

 small quantity of quicklime is sprin- 

 kled upon them when they are a few 

 inches high, experience has shown 

 that the plants remain uninjured, 

 while the aphis is totally destroyed. 



" Turnips are subject to several 

 peculiar diseases, and are the food of 

 many noxious insects. On the first 

 appearance of the leaves, a whole 

 host of little jumping beetles {Haliica 

 ncmonim), called by farmers the fly 

 and blackjack, attack and devour 

 them, so that the land is often obli- 

 ged to be resown. Nearly as much 

 damage is sometimes caused by a lit- 

 tle \\ee\\\{Curculio contractus, Marsh- 

 am), which in the same manner pier- 

 ces a hole in the cuticle : watering 

 with limewater, &c., may serve to 

 check both these evils. 



" The hop is liable to many disea- 

 ses caused by insects. When the 

 plants first emerge above the ground, 

 they are infested by a small beetle 

 {Haltica concinna), vulgarly called the 

 flea. In a more advanced state the 

 tops and branches are devoured by 

 the hop aphis, known to some by the 

 name of the green fly, while at the 

 same period the roots are subject to 

 the attack of the caterpillar of a sin- 

 gular species of moth, named by col- 

 lectors the ghost moth. 



" Clover is very subject to be in- 

 jured by a very small weevil {Apion 



425 



