STRAWBERRY INSECTS 391 



look sickly or die they should be removed and destroyed. If 

 the work is done carefully, many of the grubs will adhere to the 

 roots. 



Experiments in California have shown that a large percentage 

 of the grubs can be killed without injury to the plants by in- 

 jecting one third ounce of carbon bisulfide into the soil every 

 18 inches in the rows. This should be done early in the season 

 before any of the grubs have transformed. This treatment is 

 too laborious and expensive for use on a large scale. 



References 



Riley, Rept. U. S. Ent. for 1879, pp. 255-257. 1880. 

 Chittenden, Bur. Ent. Bull. 27, pp. 88-96. 1901. 

 MaskeV, Bur. Ent. Bull. 44, pp. 46-50. 1904. 

 Van Dine, Haw. Agr. Exp. Sta. Press Bull. 14. 1905. 



The Strawberry Root-worms 



The larvae or grubs of three species of small leaf-beetles at- 

 tack the roots of the strawberry and frequently cause con- 

 siderable loss, especially in old beds. While the beetles are 

 easily separated the grubs are so nauch alike that it is very diffi- 

 cult to distinguish the different kinds and they are therefore 

 known collectively as the strawberry root- worms. When, ma- 

 ture they are from | to ^ inch in length, white with a pale j^ellow- 

 ish-brown head and first segment and are strongly curved like 

 the common white-grub. Although the injury inflicted by the 

 various species is practically the same, they differ considerably 

 in habits and life history. 



Typophorus canellus Fabricius 



This is the most abundant and destructive of the root-worms 

 and is often referred to as the strawberry root-borer. The 

 beetles are about | inch in length and vary greatly in 

 coloration from nearly black to reddish-yellow with blackish 



