18 



This matter of distinguishing between the two is of decided impor- 

 tance, because, while the feeding habits are similar, there are vitally- 

 important differences that affect remedial measures. The yellowheads 

 are, on the whole, stouter than the blackheads, and, as a rule, lighter 

 in color. They are also less active and, especially when nearly full 

 grown, do not so readily wriggle out of their nests. 



The yellowheads grow fast, and are ready to pupate late in May or 

 very early in June, a little before the blackheads. The second moths 

 appear early in June, but are now bright orange red in color, whereas 

 the first moths were slate gray. The second lot of eggs hatch toward 

 the end of June, and the yellowhead worms are nearly half grown 

 when the cranberries are in full bloom, early in July, when the second 

 brood of blackheads has just started. They make even larger webs 

 than the blackheads, and are even 

 fonder of boring into the fruit. 

 It is not uncommon to see half a 

 dozen uprights and runners all 

 tied together in one large web, in 

 which leaves, even if not eaten, 

 turn brown and die. By the mid- 

 dle of July or a little later the 3'^el- 

 lowheads are again full grown and 

 change to pupa3. The worms spin 

 a silken cell, in which the change 

 takes place, and the pupa (fig. 6) is 

 dark brown or blackish, with a 

 little knob-like protuberance on 

 the head case. This peculiarity 

 makes the species easily distin- 

 guishable from the same stage of 

 the blackheads. 



The third crop of moths appears late in July or early in August and 

 are of the same orange-red color as the second. Eggs laid by these 

 moths do not hatch until in August or even early in September, and 

 the worms that come out of them grow slowly as compared with the 

 earlier broods. Few of them spin up more than a single shoot and 

 few of them eat into any Ijut the smallest berries. They also tend to 

 become reddish in color and even striped, so that at one time they 

 were believed to form a distinct species, described as the " red-striped 

 cranberry worm." Not until after the picking, if anything be left to 

 pick, do these worms become full grown. Very irregularly in late 

 September and early October they come to maturity, and now the 

 moths that come from them are, after a dust of orange wears off, of 

 the slate-gray color seen in spring. 



178 



Fig. 6. — Yellowhead cranberry worru; a, larva; 

 b and c, pupa — much enlarged (author's illus- 

 tration). 



