THE CODLIN MOTH IN IDAHO IN 1900. 



Upon leaving the apple the worm immediately seeks a place to spin 

 the cocoon. The place usually selected is under rough, loose bark, in 

 cracks or holes of the tree-trunk and larger branches, under bands oi- 

 cloths on the trees — in fact, in almost any dark and tight crack or crevice. 

 M^ny cocoons are placed in cracks in the ground about the trees. This 

 is especially true when the tree-trunk is smooth and offers no suitable 

 place. Mr. McPherson says he has found many cocoons among the clod!> 

 of earth in his orchard. Where apples are stored the worms spin the 

 cocoons in the boxes. I have found as many, as thirty cocoons in and on 

 one box. Having found a satisfactory place, the larva spins a tough 

 silken case. In the earlier broods the larv^ae spin their cocoons 

 quite thin and do not usually use other substances than silk in its 

 construction. The last brood, however, build their cocoons thicker, and 

 in nearly all cases hollow out a space for it and mix little pieces of wood, 

 bark, or cloth with the silk. The larva is bent in a U shape in the 

 cocoon. If the cocoon be destroyed, the larva will set to work immediately 

 to build another or to repair the old one, if it be not completely destroyed. 



The Pupa. 



In from three to five days in the summer the larva sheds its skin and 

 becomes a pupa. In the last brood the larval stage lasts until the spring. 

 The pupa is at first of a yellowish colour, later becoming brown and then 

 bronze in colour. When the moth is ready to emerge, the pupa, aided by 

 the spines on the abdominal segments, wriggles itself out of the cocoon. 

 I have seen empty cases that had been thrust through heavy muslin 

 which was used as a band. 



These empty pupal skins are familiar objects upon infested trees. I 

 once counted fifty of them protruding from under pieces of bark in a 

 space of about a square foot. During the w^armer season the time spent 

 in the cocoon is from seven to eleven days. Many stay in a longer, but 

 very few a shorter time. The last brood stay in the cocoon about eight 

 months. 



The Moth. 



The moth is a beautiful insect whose front wings have the colour of 

 brown watered silk, and are crossed by lines of brown and grey scales. 

 Near the tip of the wing is a large bronze-coloured spot. The hind wings, 

 which are concealed during repose, are of a greyish colour. The moth 

 varies in size, but never expands over an inch. The sexes may be dis- 

 tinguished readily by the fact that the male has a streak of black hairs 

 upon the upper surface of each hind wing, and upon the under surface of 

 each front wing there is a long blackish spot. The relative number of 

 moths of each sex is about equal. 



The adult insect is rarely seen. In my summer's experience I saw 

 but five. These were either resting upon the upper surface of the leaves 

 or were upon the trunk or larger branches. In warm evenings by aid of 

 a light I saw a few flying about the trees. 



It has long been known that the moth is not attracted to lights. I 

 examined the contents of an electric (arc) light globe that was near an 

 orchard without finding a single codling moth. 



