246 AN ECONOMIC ENTOMOT.OCY. 



The hind wings are often furnished with one or two pairs of 

 slender, thread-hke tails, easily broken off if the insects are care- 

 lessly handled. None of the members of this family are injurious, 

 and the somewhat slug-like caterpillars are not often seen. 

 Fenesica tarquinius looks like one of the " coppers," and is pe- 

 culiar in that its larva feeds on the woolly plant-lice often found 

 on beech and other trees. It is the only butterfly lar\'a in our 

 country which is known to be predaceous. 



The family Papilionidce contains six-footed butterflies, the 

 anterior feet being perfectly developed in both sexes, and here 

 the antennae are set rather close together at the base. It includes 

 our largest and brightest species, the most prominent of them 

 being known as "swallow-tails." There are two groups, the 

 first containing smaller species, which are white or yellow in 

 color, the hind wings without tails, but furnished with a fold 

 along the inner margin, forming a groove, in which the abdomen 

 lies. These are arranged under the term Pierince, and contain 

 as typical forms the common cabbage butterflies. The most 

 abundant and injurious of these is Pieris rapcB, an insect imported 

 many years ago from Europe, and which has now spread over 

 the largest part of the United States and Canada. The wings 

 expand about an inch and a half, are white or with a creamy 

 tinge, with a single black spot in the fore-wings of the male, and 

 two similar spots in those of the female. There is also a little 

 black patch at the apex, and on the under side the wings are 

 usually darker and a little powdery. These butterflies appear 

 very early in spring, emerging from chrysalids that have hiber- 

 nated, and lay their eggs upon almost any of the cruciferous 

 weeds. They are not particularly choice, but perhaps the com- 

 mon Barbarea vulgaris is about as often selected as any in the 

 Middle States, because one of the first to make its appearance. 

 The first brood comes to maturity in less than a month, and then 

 eggs are laid on early cabbage-plants. Soon irregular holes 

 appear, first in the outer leaves, then in the head itself, and little 

 piles of dirty-yellow excrement may now be found everywhere 

 among the folds. The caterpillars themselves are velvety green 

 in color, almost like the cabbage-leaf, and, as they lie rather 

 closely to the plant tissue, are easily overlooked until a little 

 practice is gained in searching for them. They become more 



