126 MASS. EXPERIMENT STATION BULLETIN 192. 



Insects. 

 The Span Worm (Epelis truncataria var. faxonii Minot) . 



In 1917 a bog under the writer's observation near East Wareham was 

 reflowed June 20 while the moths of both sexes of this insect were numerous 

 on a large share of it. The water was let off June 23. It either destroyed 

 or drove ashore all the moths, very few being seen afterwards, but it 

 apparently did little or no harm to the eggs which had been laid before 

 the flooding, for the worms appeared on the bog in great numbers in 

 July. When the worms were small, this infestation was treated once 

 with 6 pounds of arsenate of lead paste to 50 gallons of water with great 

 success, no noticeable injury from what started as a severe infestation 

 appearing afterward. But few of the worms could be found by sweeping 

 the bog with an insect net a few days after the spraying. 



This insect did much harm on a bog in Carver in early August, 1918. 

 It worked late because the winter flowage had been held until near the 

 1st of June, the pupae enduring this prolonged submergence. 



The Cranberry Root Grub {Amphicoma vulpina Hentz.). 



The writer gives the above common name to a grub found occasionally 

 in great numbers in the sand covering of cranberry bogs, where it works 

 much like the root worm {Rhabdopterus picipes), feeding mainly on the 

 small roots. The infestation usually is confined to lunited areas, seldom 

 extending in severity in one patch over more than 15 or 20 square rods at 

 most. The areas affected are often very irregular, but sometimes quite 

 circular. Occasionally the injury is so severe that the vines are entirely 

 killed in patches, the roots being so eaten that they can be rolled back 

 easily like a rug. More often the infested area looks yellowish and sickly, 

 the vines failing both to grow well and to produce much fruit, this condi- 

 tion usually lasting several years. Vines thus affected often die suddenly 

 in patches, or their growing tops and green berries wither, this happening 

 only in periods of hot, dry weather. It probably takes vines that are not 

 killed two or three years to recover after the insects finish their work and 

 disappear, as they finally do. 



The grubs look somewhat like those common in gardens, but are smaller 

 and with a thin coat of fox-red hair which is well distributed over the 

 body. They are from 28 to 30 millimetres long when mature, but all 

 sizes from 8 millimetres long up are commonly found working together, 

 the various sizes perhaps being of different broods. 



The writer has never reared the adults of this species, but he found 

 associated in the soil with the grubs of one infestation great numbers of 

 both sexes of the beetles of Amphicoma vulpina Hentz. ^ Many pupse and 

 pupa skins of this species were also present. These beetles were first 

 found July 5, 1917. They were in a dormant condition, most of them 

 being about 3 inches below the surface of the sand. They were present 

 in about the same numbers and condition on July 11. On July 17 these 



1 Identified by Mr. A. I. Bourne of the Massachusetts Agricultural Experiment Station. 



