Cases are on record where over fifty grubs of this species have 

 been spaded out from under a single stool of cane. It is no uncom- 

 mon occurrence to dig out twenty or more grulis from one cane stool. 

 So prolific is the species that it requires constant vigilance on the 

 part of the sugar centrals of the infested district to keep the insect 

 in check. Boys are paid at a regular rate per quart for beetles 

 collected on the cane foliage by lantern at night, and women are 

 paid by the quart for grubs collected in the plowed fields in the day- 

 time. By these means hundreds of bushels of l)eetles (see PI. II, 

 fig. 4) and grul)s are collected every season and destroyed, or fed 

 to hogs. 



Some idea of the cost of this propaganda may be derived from 

 the following figures, available through the courtesy of the general 

 manager of Guanica Centrale, where accurate records of the daily 

 collections of grubs and beetles are kept : 



In seven months of 1914 during which collections of beetles were 

 made (February 27 to September 23), the total collections in five 

 haciendas belonging to Guanica Centrale amounted to 2,255,000 bee- 

 tles, gathered at a total cost of $833.87. 



The collections of grubs for six months of the same year (from 

 November 27, 1913, to May 14, 1914) amounted to a total of 1,662.000 

 grabs, gathered at a cost of $1,876.73. 



In six months of the following year (March 6 to September 9, 

 1915), on the same haciendas of Guanica Centrale, tiie collections 

 of beetles amounted to a total of 2,468,000, gathered at a cost of 

 $1,425.20. 



The numl)er of grubs collected in seven months of 1914 and 1915 

 (from October 29 to May 27) amounted to a total of 2,425,000, gath- 

 ered at a cost to the central of $2,018.57. 



Figuring 400 l)eetles to the quart, and 300 grubs to the quart, 

 this makes the rather startling figure of 369 ))ushels of beetles and 

 426 l)ushels of grul)s collected in two years from a small district by 

 one sugar central, at a total cost of $6,154.37. 



And still this l)eetle is not held in check, but appears to continue 

 to increase in abundance. It is small wonder that tlie sugar-cane 

 growers of Porto Rico have become exercised over the depredations 

 of the "gusano bianco," as the white-grub is known locally. 



THE BEETLE. 



The adult of PJiyUoplhaga vandinci is a ^lay-beetle of normal 

 appearance, smooth and faintly shining in both sexes, but not pol- 



69 



