THE BLACKHEAD FIEEWOEM OF CEANBEEEY. 11 



Depending upon the prevailing temperature and the condition of 

 the weather at this time, the young larva in a somewhat dormant con- 

 dition spends two weeks, more or less, in its burrow, feeding only 

 when the weather is warm and favorable. If the weather is warm it 

 will be quite active and may stay in its burrow only two or three days. 

 On badly infested bogs it is a common thing to find the underside of 

 the lower leaves on the vines badly chewed and full of burrows. The 

 majority of instances of this type of injury are doubtless caused by 

 the larva hatching early in the spring before the bogs have become 

 sufficiently warm to permit active feeding, and also by those hatching 

 late in the fall, as is often the case on account of the bogs being ex- 

 posed to the weather the year round. 



At the approach of warm weather, or after the young larva has 

 grown larger and stronger, it leaves its burrow and proceeds toward 

 the tip of the upright. Here, if the weather should turn cool, it 

 starts to feed in the whorl of leaves about the terminal fruit bud and 

 incloses itself in a loosely constructed web of frass and silk, either 

 between two terminal leaves or between the bud and the adjoining 

 leaf, where it awaits more favorable conditions which may cause the 

 terminal bud to break and grow. As these conditions become intensi- 

 fied the larva proceeds to web up the unfolding leaves as it feeds 

 on and skeletonizes them from within. From about the latter part 

 of May or the beginning of June this injury is noticeable to the 

 casual observer, many of the short, new uprights assuming a withered 

 and bent-over appearance at the tip, similar to those shown in the 

 accompanying illustration (fig. 4). 



As the weather becomes warmer and the vine growth increases the 

 fireworms, the majority of which at this time (about early June) 

 may be nearly one-half to three-fourths of an inch long, feed rapidly 

 on the leaves in their web galleries, gradually extending them or 

 moving to an adjacent tip or upright as new food is needed. The 

 vines gradually assume the characteristic dried, light yellow-brown 

 appearance, and as feeding continues the bog begins to look as 

 though a fire had swept over it, scorching the tips of the vines, 

 which by midsummer are dry, reddish brown, and often nearly 

 leafless ; whence the name " fireworm." 



On a vigorously growing bog the late-hatched larvae of the first 

 generation often feed upon the unfolding blossoms and newly 

 formed berries, sometimes causing them to drop from the vines. In 

 their feeding the young larvse frequently burrow into the blossoms 

 at a point near the base of the petals and feed on the floral organs 

 within, or they may bore into the ovary directly from the outside. 

 This feeding is first noticed about the time when the blossoms are 

 in the "hook stage" or about the beginning of June on the early 

 bogs. At this time a few very small larvae usually may be seen eat- 



