THE CRANBERRY ROOTWORM. 7 
New Lisbon, N. J. ; was the first to introduce this method of preparing 
arsenite of soda for use in the spraying of New Jersey cranberry bogs. 
In the first two applications arsenic was used at the rate of 1J 
pounds per acre, the later applications being increased to 2 pounds 
per acre. Arsenite of lime, prepared and used as just described, is 
exceedingly cheap compared to arsenate of lead, but the dangers 
attendant upon its use by inexperienced help, both to human life 
and from possible injury to the foliage and fruit, are such that it is pre- 
ferred to recommend arsenate of lead for general use. The latter 
insecticide is frequently used on cranberry bogs at the strength of 
3 pounds of paste arsenate of lead to 50 gallons of water or Bordeaux 
mixture. If arsenite of lime is used as the insecticide, it is very essen- 
tial that thorough agitation of the spray material be maintained. 
Some foliage injury, noted on three different bogs, should probably 
be attributed mainly to a neglect to keep the mixture agitated at all 
times when spraying. At the conclusion of the second season's obser- 
vations no new areas on the sprayed bog were found infested and the 
number of larva? throughout the bog had decreased to a marked degree. 
Having observed on a number of bogs that the injury by the root- 
worm almost invariably occurs on sandy land and, further, that the 
root system of the cranberry on such land is exceedingly shallow as 
compared with that on peat or muck lands, it is fair to conclude 
that treatment of the bog by fertilizers to stimulate growth will 
be of great advantage to the cranberry plant in outgrowing the 
injury of the larvae. 
The New Jersey Experiment Station has amply demonstrated at 
Whitesbog, N. J., that weak vines on sandy soil can be made to pro- 
duce an abundance of vines in one season by the application of the 
proper mixture of chemical fertilizers. It so happens that this land 
is infested with rootworms, but the extent of the infestation could 
not be definitely determined without tearing up the fertilizer plats 
more than is advisable. Some of the plats are known to be infested, 
but in spite of the presence of the rootworms the vines have made so 
much growth in two years that pruning would not be inadvisable. 
Sanding infested areas also gives promise of being a satisfactory 
method of promoting vine growth. Mr. T. B. Gaskill, of New Egypt, 
N. J., has clearly demonstrated on a small, badly infested area of 
savanna land that a 1-inch coat of sand will cause the vines to grow 
vigorously, sending out runners which cover the bare spaces, and to 
present a marked contrast to unsanded adjacent vines. 
SUMMARY. 
The cranberry rootworm (Rhabdopterus piciipes Oliv.) is the larva 
of a small brown beetle which has recently been found on a number 
of cranberry bogs in New Jersey. 
