" One of tlie most destructive 

 among these insects to the roots of 

 grass and grain is the Tlpula oleracea. 

 The larva is said, by some authors, 

 merely to loosen the roots by bur- 

 rowing among them ; but others as- 

 sert that it likewise feeds upon the 

 fibres. No effectual remedy has yet 

 been discovered for this evil ; and 

 Steckney observes, that the insect is 

 not killed by lime, even when applied 

 in much larger doses than usual. 



" There are several other species 

 of a large size, as the Tipula crocata 

 {Fig. 5, a), and Tipula nro5a(c) which, 

 in a less degree, are also injurious to 

 such lands as are moist and humid. 



" Another minute species is partic- 

 ularly destructive, and is generally 

 known as the wheat ^y {Tipula or Ce- 

 cidomyia tritici, d, magnified) ; its his- 

 tory and economy have been ably in- 

 vestigated by Mr. Marsham and Mr. 

 Kirby. The injury first appears in 

 the ear, several of which, on being 

 opened, will be found to contain an 

 orange-coloured powder ; in this are 

 concealed very minute larva;, which, 

 on being magnified, are seen to be 

 thick at one end, extending and con- 

 tracting themselves at pleasure, and 

 frequently jumping half an inch at 

 one spring : they take their station in 

 the longitudinal furrow of the grain, 

 and, by sucking its milky juice, cause 

 it to shrink up, and become what the 

 farmers call pungkd : the last sown 

 wheat always appears the most in- 

 fected. In the beginning of June the 



perfect insect {d) may be seen in in- 

 numerable multitudes, flying in the 

 evening in all directions over the 

 corn-fields ; but during the day not 

 one is to be perceived. The female 

 lays her eggs by means of a retractile 

 tube, which encloses a very long and 

 acute sting resembling a hair ; but 

 this can only be distinctly seen when 

 the insect is magnified. The wheat 

 fly would soon become a formidable 

 enemy to mankind, were not its race 

 exposed to an inveterate foe, scarce- 

 ly larger than themselves ; this is 

 the Ichneumon Tipula, the female of 

 which carefully searches out the 

 grubs of the wheat fly, and deposites 

 in each one of her eggs ; these are 

 hatched, and ultimately the larva de- 

 vours the body which gave it life. 

 One ichneumon will thus cause the 

 death of many dozens, and prevent 

 the future multiplication of thou- 

 sands. The only palliative that has 

 been recommended for stopping the 

 progress of this insect originated 

 in Mr. Kirby : this naturalist thinks 

 much benefit would be derived by fu- 

 migating the corn with tobacco and 

 sulphur, when the wind is in a fa- 

 vourable quarter : this must be done 

 as soon as the ear begins to shoot 

 from the leafy stalk.^ — See Wheat In- 

 sects. 



" Insf.cts injurious to Food, Clothing; 

 <!j-c. — The cockroach is called by some 

 the black beetle {Blatta oricntalis). 

 Like most of its tribe, it shuns the 

 light, both natural and artificial. It 



429 



