No. 4.] INJURIOUS INSECTS. 149 



The Cranberry Span-worm. 



The cranberry span-worm {Ematurga faxonii) is oc- 

 casionally so abundant as to do much damage on bogs 

 where it occurs. I visited several bogs where it absolutely 

 ruined the crop for that season. Those which I bred laid 

 their eggs on May 28, 1896, and hatched in twelve days. 

 The caterpillars fed on cranberry leaves, reaching their full 

 growth July 13, when they went just below the surface of 

 the ground and changed into dark-brown pupae, in which 

 state they spent the winter, and the moths emerged during 

 the latter part of the following May. This insect has been 

 known to feed on arbor vitse or cedar ( Thuja occidentalism 

 as well as on the cranberry. 



If the cranberry growers would learn to recognize these 

 insects in their different stages, it would aid them very 

 much in destroying them. If this particular moth which 

 gives rise to the cranberry span-worm should be seen flying 

 in large numbers over a bog late in May or early in June, 

 we may expect trouble from the span-worms, and should 

 make preparation to spray the bog with arsenate of lead at 

 the time the eggs are hatching, or about the 10th of June. 

 It is extremely unwise to wait till they have grown and de- 

 voured the leaves to such an extent as to ruin the crop for 

 that season, for it costs no more to spray early than it does 

 later ; and, further, the younger the caterpillars are, the 

 more readily do they succumb to the poison. 



Other Cranberry Insects. 



In addition to this, there is a second species of span-worm 

 {Eupithecia iriiplicata) which we have found feeding on cran- 

 berry vines. It is much smaller than the common species, 

 being only a])out as long as the vine worm. So far as I can 

 learn, they are nowhere very common on the bogs ; but I 

 know of no reason why they may not at any time become 

 abundant, and cause as much damage as the larger species. 

 This insect is known to feed not only on the leaves of the 

 cranberry but also on cedar {Thuja occidentalis) , juniper 

 {Junijperus coinmunis) and different species of oak. 



The tip worm {Cecidoiayia vacciuii) is comparatively 



