ENTOMOLOGY 99 



cause no damage at all and the late broods very little. On old bogs, 

 with long vines, the earlier broods do little harm, but the later 

 broods materially injure the crop prospects for the year following 

 by preventing the set of buds on the injured uprights. 



Strictly speaking, no direct remedial measures are known. It 

 is not known positively how the insect passes the winter; hence 

 control can not be attempted at that season. The worm never 

 comes within reach of our ordinary insecticides, and therefore di- 

 rect attack is not possible. Since the loss of the tips attacked in 

 spring does not injure the crop of that year, the effort must be to 

 keep the vines in such vigor that they will set fruit buds on laterals 

 and at leaf axils when the direct tip has been lost. How this vigor- 

 ous growth is to be obtained the grower will be best able to deter- 

 mine. 



This insect is not confined to the cranberry, and in fact breeds 

 much more abundantly on loose strife and on some of the heaths. 

 Therefore, where the species is troublesome, those plants should be 

 kept down on the dams and other bog surroundings. Tip worms 

 occur on both flowed and dry bogs, and reflowing does not reach 

 them ; but as they first occur on flowed bogs around the edges, the 

 inference is that the winter is passed on the upland, on or in some 

 one or more of the alternate food plants. This would make the 

 destruction of such plants an effective measure. 



The Cranberry Spanworm.* In some sections of Cape Cod 

 certain span, inch or measuring worms occasionally become in- 

 juriously abundant, and the most destructive of these is the species 

 above named. The parent moth is much larger than any of the 

 other forms found on the bogs, the broad fore wings expanding 

 li/2 .inches or thereabouts. In general color it is pale ash gray, 

 sprinkled with black, and both wings are crossed diagonally by 

 black lines and shades. The lines have a tendency to become 

 toothed or scalloped, and the wing margins themselves are also a 

 little notched. The worms first appear on the bogs in June and be- 

 come full grown by the end of that month or early in July. They 

 are then rather more than an inch long; slender, smooth, livid 

 gray caterpillars with a deeply indented head and a long, pointed 

 anal plate. They have three pairs of short legs close behind the 

 head and two pairs near the anal end. When they walk, they first 

 stretch out at full length, take hold with the anterior legs, then 

 bring the posterior pairs close to the others, the middle of the body 

 forming a loop. This mode of progression gives them the common 

 name "loopers" in addition to jthose already mentioned. At rest 

 or when not feeding, the caterpillars hold fast by the anal legs 

 only, and stretch out the remainder of the body at an angle, and 

 so rigidly that they resemble leafless bite of vines. On a section of 

 bog on which they have been feeding the observer may stand in 

 the midst of thousands of them and see none until something 

 starts them into motion; then it appears almost as though the 

 entire bog was alive. 



* See page 645, for illustration. 



