THE CELERY CATERPILLAR. 
(Papilio polyxenes Fab.) 
By F. H. Chittenden, Sc. 1). 
In Charge of Truck Crop and Stored Product Insect Investigations. 
INTRODUCTION. 
Everywhere in beds of celery, carrots, parsley, and related plants 
there will be found, during summer and autumn, numbers of a large 
green or yellowish caterpillar, ringed with black. This is the celery 
caterpillar, known also as the parsley worm and by other common 
names. It is, everything considered, one of the insects best known 
to the grower of the crop plants mentioned, this being due to its 
large size and conspicuous, gay coloring. It feeds upon the leaves 
of plants and, when abundant, attacks the blossoms and undeveloped 
seeds. If left entirely unmolested it might, save for the intervention 
of natural enemies, become a serious pest, since it is a voracious 
feeder. It is readily controlled, however, by handpicking, and this 
helps to reduce the numbers of the pest. In addition, its habit of 
feeding on wild parsnip, wild carrot, and other umbelliferous weeds, 
which are altogether too abundant, serves to distribute attack as 
well as to divert it from useful plants. 
DESCRIPTIVE. 
Nearly every year inquiries are made in regard to this insect, but 
it is seldom so plentiful as to call for advice in regard to treatment. 
Complaints of injury and requests for remedies, however, have 
been received in recent years from portions of Long Island, Maryland, 
District of Columbia, Virginia, Iowa, and some other regions. In 
our correspondence it has attracted most attention because of its 
occurrence on celery, parsley, and sweet fennel. 
The egg. — The egg of this butterfly is of globular form and rather 
large, measuring about 1 mm. in width and the same in height. It 
is flattened on the surface by which it is attached, as shown in figure 
5, d. When first laid the egg is pale honey-yellow, but afterwards 
turns in parts to reddish brown. The surface is slightly glistening 
and covered with microscopic granulations. 
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