CRANBERRY INSECT PROBLEMS. 



21 



the entnince hole with a thin, silken web. 

 The seeds are eaten and usually some of the 

 pul]) in the hrst berry, after which the berry 

 is vacated and the larva attacks another. 



The berry turns red prematurely soon 

 after it is attacked, and gradually shrivels, 

 but may hang on the vine until another 

 spring. The entrance to the first two or 

 three berries is closed by a silken web, unless 

 the worm can fasten adjacent berries to- 

 gether and thus pass from one to another without exposing itself 

 to the attack of parasites. The number of berries destroyed varies 

 with their size, but most of the pulp is eaten in all except the first. 



Frequently larvae that are late in maturing are carried in the 

 berries into the warehouses, and in some cases the number has been 

 so great that a large part of the crop has been ruined in storage. 



Fig. 19. — Cranberry fruit- 

 worm : At right, cocoon ; at 

 left, moth. About twice en- 

 larged. 



Description .\nu Seasonal Histokv. 



HIBERNATION. 



Upon completing its feeding the larva descends to the sand under 

 the vines on or near the surface of which it spins an oval cocoon about 

 five-sixteenths of an inch long (fig. 19, at right). The cocoon usually 

 is composed of grains of sand held together with strands of silk, but 

 lacking sand the worm will not refuse peat or trash for this purpose. 

 Each year a few larvae spin up within the last berry which they 

 attack. Although the cocoons are not impervious to water, the larvae 

 hibernate successfully under the customary winter floAvage. Hiber- 

 nation begins in August and continues until the following June or 

 July. 



The newly hatched larva usually enters the berry near the stem 

 end, but most berries, after the first two, are entered at the side, and 

 in only the first two or three is the entrance closed. 



The larvae are active from about July 1 to August 30, but also may 

 be found in September within the berries. At this time the worm 

 measures slightly more than half an inch in length and is green, 

 tinged with red on the back. The head is yellowish, Avith brown 

 mouth parts. A few sparse, long hairs clothe the body. (Fig- 20.) 



I THE PUPA. 



In the pupa stage the insect "is at first whitish but soon changes to 

 yelloAV and a few days before emergence to dark brown. Pupation 



