10 BULLETIN 554, U. S. DEPARTMENT OF AGRICULTURE. 



Investigations conducted in this region demonstrated beyond doubt 

 that there is only one generation annually. Field records kept on a 

 number of badly infested bogs throughout the entire season showed 

 only a single flight of moths from about June 10 to mid-July, after 

 which there was no further evidence of moths until the following 

 year. This was also demonstrated in a mosquito-bar cage covering 

 2.4 square rods, from which moths issued from June 10 to July 8, 

 and although oviposition occurred in the cage, none of the larvae 

 pupated during that season. 



Larvae are rarely found in wet situations or in places where a lack 

 of drainage is materially affecting the productiveness and health of 

 the vines. 



The drier locations, such as knolls, the high margins of the bogs, 

 and well-drained areas having a considerable quantity of fallen 

 leaves and trash under the vines are the places injuriously infested. 

 The character of the soil is not so important a limiting factor as the 

 drainage. Severe injury occurs on mud and peat bottoms as well as 

 on savannas, provided a good layer of trash is present and the land 

 is well drained. 



Larvae are never found feeding in exposed positions, but always 

 buried beneath more or less trash. When exposed to the light, as 

 when trash is turned over, they usually are found in a curved 

 position and motionless. After a period of about 10 seconds the 

 larvae will start crawling rapidly for cover, and it is at this time 

 that they are most easily detected. The trashy nature of the infested 

 situations also renders their location difficult. Many growers have 

 failed utterly to locate the larvae, although the vines may have shown 

 injury of an extreme type. 



The amount of damage done by the cranberry girdler seems out 

 of all proportion to the number of larvae to be found in a given 

 location. In one instance, however, the writer found 30 cocoons 

 containing larvae and 1 naked larva in an area of about 4 square feet. 



What appears to be the most important point in the seasonal 

 history of this pest from the standpoint of its control is the period 

 when cocoon making begins. The few publications available on the 

 seasonal history of the cranberry girdler present various statements 

 regarding the time of cocooning. Some writers have placed the 

 period as late as November, and others have indicated this period as 

 beginning at varying dates in September and October. Eealizing 

 the importance of knowing more definitely when cocooning com- 

 menced, the writer has made collections of larvae and cocoons in the 

 fall, and from these data it may be stated for New Jersey condi- 

 tions that some larvae form cocoons in late September and the ma- 

 jority in early October. Records obtained from bogs in different 

 localities are shown in Table IV. 



