INSECTS, ETC 165 



are hatched, producing small green larvit, which cause 

 large blisters upon the leaves. These larvae, or maggots, 

 cause complete or rapid decay of the foliage. The brown 

 pupae of this fly are found on the leaves of the host plant 

 and in the earth; as a rule, the maggots leave the host 

 plant and turn to pupae in the earth. There are several 

 broods during the year, but the pup^3e last produced hiber- 

 nate in the soil until the following spring, when they 

 appear as perfect insects and renew the attack. 



Eemedibs. — Owing to the maggots feeding within the 

 leaves, it is difficult to apply any insecticide that will 

 reach them without at the same time destroying the 

 foliage. Picking off the portion of leaf infested, and burn- 

 ing the collected portions, is the only remedy once the 

 maggots are in the leaves. The flies may, however, be 

 prevented depositing their eggs by spraying the foliage 

 occasionally with the following preparation: Mix half a 

 gallon of tar with a gallon of water, and place this on a 

 fire till it boils. When cool add fifty gallons of water, 

 and then spray the foliage thoroughly with it. Another 

 good plan is to pour as much paraffin oil on a piece of 

 l)rick as it will absorb, then steep this for a day or two in 

 three gallons of water. Kemove any scum that forms, 

 then spray the foliage. Spraying should be done dvu-ing 

 May, June, and July. Before preparing the trenches 

 dress the ground with one of the soil fumigants previously 

 described, to destroy the pupae and prevent them develop- 

 ing into flies. 



Celery-Stem Fly (Piophila apii). — The fly is some- 

 what similar in size and form to the Celery Fly, which 

 see. It has a black, shiny body, clothed with golden 

 hairs. The maggot is yellowish-white. The latter bores 

 into the root stock of the celery, and thence upwards in 

 the leaf-stalks, causing rusty-brown patches to form. 



Eemedy. — There is only one, and that is to burn all 

 infested plants, and dress the soil with one of the soil 

 fumigants to kill the pupae. 



