236 THE STUDY OF INSECTS 



The case made by certain of the leaf-eating species is 

 very characteristic in form (Fig. 282), being strongly taper- 

 ing and much curved ; in this instance the 

 case is composed largely of the excrement of 

 the larva. 



The Indian-meal Moth, Plodia interpunc- 

 tella (Plo'di-a in-ter-punc-tel'la) is the best 

 known of the species that infest stored 

 provisions. The larva is the small whitish 

 worm, with a brownish -yellow head, that 

 spins thin silken tubes through meal or among 

 yeast-cakes, or in bags or boxes of dried fruits. The moth 

 expands about five eighths of an inch. The basal two fifths 

 of the fore wing is dull white or cream-colored ; the outer 

 part reddish brown, with irregular bands of blackish scales. 



The Mediterranean Flour -moth, EpJiestia kilhniella 

 (E-phes'ti-a kuhn-i-el'la), is an even more serious pest than 

 the preceding species, which it resembles in habits. It has 

 become very troublesome in recent years in flou ring-mills, 

 The moth expands about one inch, and is grayish in color. 

 Although it is called the Mediterranean Flour-moth, its 

 source is not definitely known. Nor do we know of any 

 easy way of ridding an infested mill of it. Carbon bisul- 

 phide is perhaps the most available insecticide in this 

 case. 



Zimmermann's Pine-pest, Pinipcstis zimmermanni (Pin-i- 

 pes'tis zim-mer-man'ni), is a common species, the larva of 

 which is a borer. It infests the trunks of pine, causing large 

 masses of gum to exude. The moths appear in mid- 

 summer. 



The Coccid-eating Pyralid, Lcetilia coccidivora (Lae-til'i-a 

 coc-ci-div'o-ra), differs from the other members of this 

 family in being predaceous. It feeds on the eggs and 

 young of various scale-insects {Pufoinaria, Dactylopius, and 

 Lecaniuni). Figure 283 represents the different stages of 

 this insect enlarged, and the moths natural size resting on 



