CARROT AND PARSNIP FLY. 
31 
other points, as nature of succeeding crop, and time that can be 
allowed for the gas-lime or “ waste” to be exposed. Those who wish 
to go into the nature and uses of gas-lime as an application to the soil 
will find excellent observations in Dr. Voelcker’s four-page leaflet, of 
which the title is given below.* 
I must also add on my own account that, although a fungoid 
disease and its cure do not lie in my own department, yet, as they 
have been constantly brought under my notice and study for years, I 
hope I shall not be considered trespassing out of due limits in giving 
the above notes much based on the observations of two such widely- 
known and eminent authorities as Mr. Worthington Gr. Smith and the 
late Dr. Aug. Yoelcker. 
CARROT. 
Carrot and Parsnip Fly; “ Rust.” Psila rosce, Fab. 
1, 2, and 3, maggots, nat. size and magnified; 4, infested Carrot; 5 and 6, 
chrysalids; and 7 and 8, Carrot Fly, nat. size and magnified. 
“ Rust ” in Carrots is so called from the peculiar yellowish or rusty 
colour of the parts injured by the Carrot Fly maggot. Whilst the 
Carrots are still young, the maggot-galleries are often, or most com¬ 
monly, to be observed towards the outside of the lower part of the 
root; later on they may be found in any part of it, and sometimes 
penetrating to the middle. 
The presence of the mischief may often be known by the yellow 
colour and the withering of the leaves, and, if a root is carefully 
withdrawn from the soil, the little maggots may be seen sticking (by 
* “ On the Composition and Use of Gas-lime in Agriculture,” by Dr. Augustus 
Voelcker; four pages. Reprinted from the ‘Journal of Gas-lighting,’ &c. Printed 
by W. King and Sell, 12, Gough Square, Fleet Street, London. (Probably procurable 
on application, or through a bookseller.) 
