225 



Kia' To 'IMIM J)IS(UiSSI()N OK INSPX'T IN.JUH1I<:S TO CORN. 



'Jlic following analy.sis of insect iiijui-ics (o the corn plant in intended 

 t-o aid the observer of such injuries lo Hnd the essential matter relating 

 to anyone of them coutainecJ either in the })resent report or in the Eigh- 

 teenth Report of this office — devoted to insect injuries to the under- 

 ground parts of the plant. The use of this synopsis or key will be easy 

 to those accustomed to the determination of species, either of plants or 

 of animals, by means of ordinary analytical tables; ])ut to others, some 

 explanation may be necessary. 



With an example of an injury under examination, the observer will 

 (irst refer to the "CJeneral Grouping of Injuries to Corn," on this page, and 

 will ascertain under which of the six groups there giv(Mi his example be- 

 longs. Against the description of each of these groups is a reference to 

 a page where the group is further analyzed, and to this analysis he 

 will of course turn next. 



8u})pose, for example, that he has a corn plant tiie leaves of which 

 have rows of similar holes running across the blade. Heferring to the 

 general groups below, he finds that injuries to the leaves are analyzed 

 on ])age 226. (Joing to this analysis and reading the first two items of 

 the table, he assigns his specimen to the first, — that of "Injuries to the 

 green leaf," — and is thence referred to the series of items numbered "2," 

 under the second of which — "Regular parallel rows of similar holes run- 

 ning across the leaf of the young plant" — he gets a reference to colored 

 Plate III. of this report, and to page 229, where snout-beetles injurious 

 to corn an^ j)artially analyzed by a supplementary key, which re(|uires 

 that the insect itself should be in hand. Even if the beetle responsible for 

 the injury has not been detected at work, the facts concerning this class 

 of injuries may be found by following up the page references under the 

 various items of this table, since this will give an exhaustive account of 

 all i\\v ins(H'ts producing this injur3^ 



It will be seen that in the preparation of this key no technical terms 

 have been used except where necessary to an intelligible exj)ression of 

 th(> meaning. It will also be noticed that the character of the injury 

 to the plant has been depended upon, so far as plain and available, the 

 insecls themselves being used to help out where the injuries arc not clearly 

 distinguishable and recognizable. 



(iKNEUAL Grouping of In.tui?tes to Corn. 



A. Ill juries [o the leaves p. 226 



1^. Injuries to the .stalk above ground p. 226 



('. Injuries to the silks or to the kernels at the tip of the ear or beneath the 



husks p. 226 



I ). Injuries to the tassel p. 227 



10. Injuries atrectinfi; the whole platit p. 227 



l'\ Injuries to the undergrountl })arts of the plants — the roots, the planted 



seed, or the stalk near the roots p. 227 



