44 



As to the way in which the Psila makes its attack, I find a slight dif- 

 ference of opinion between a contribution to "Le Journal d 'Agriculture 

 pratique de France," whose name I don't know, and Miss Ormerod, quoted 

 by the regretted late Dr. Fletcher. The French contributor says: "The 

 female has a pretty long and retractile ovipositor through which it deposits 

 its eggs at the collar or neck of the plants." On her side, Miss Ormerod 

 says : " To present the attack in general, the necessary thing is to have the 

 soil well prepared which allows the plant to grow rapidly and which is not 

 subject to crack ; then, at thinning time, we must see that no opening is 

 left through which the fly could penetrate to the root and deposit there its 

 eggs. If the fly cannot reach the roots to deposit there its eggs, it is under- 

 stood that they will contain no larvae, and the reason why some carrots 

 which thrived till thinning time run to waste afterwards comes often from 

 the fact that, at thinning time, the soil was opened." 



As I have just read, one says that the fly deposits its eggs at the collar 

 or neck of the plants, the other says that it deposits them on the roots. I 

 confess that my own observations on this subject did not go far enough to 

 enable me to decide who is right. In doubt, by what is written farther 

 below, it is better to suppose that Miss Ormerod is on the right side. 



Here is what she says on this subject: "The carrot-fly, when she is 

 ready to lay her eggs, looks for a crevice or crack near the carrots, in the 

 soil, and there it deposits its eggs either on the carrots or near by. The 

 small yellowish or whitish larvae which hatch from the eggs penetrate into 

 the root itself or, if this root is very small, they destroy its interior part. 

 The grubs may be found in winter as well as summer, and attack all parts 

 of the carrot root by gnawing galleries on the surface, or in the substance 

 of the root; but whilst the roots are young, the grubs seem generally to 

 attack the lowest part. If infested carrots are carefully drawn from the 

 earth, the grubs will be seen on the root, sticking out of their burrows by 

 about half their length. The attacked carrots may be known by the outer 

 leaves turning yellow and withering, while the roots gradually sicken and 

 die from the injury to the fleshy part, the growth of the root fibre being 

 also often completely destroyed." 



On account of the fact that all the parts of the infested carrot take a 

 uniform color of rust very marked and that, by many of those who look at 

 these discoloured carrots, the insects are not found has suggested the belief 

 that this disease is really a kind of "rust," which explains why we hear 

 more of the "carrot-rust" than of the "carrot-fly." 



Remedies. — 1. When the young carrots are sufficiently grown to be 

 thinned, it is well, if possible, to do the thinning towards the end of the 



