INSECTS INJURIOUS TO THE STRAWBERRY 



447 



The Strawberry Crown-borer * 



Strawberry plants are often dwarfed or killed by a small white 

 larva which mines out the interior of the crown, hollowing it out 

 from the bases of the leaves to the larger roots. Usually but 

 one grub is found in a plant, and it looks very much like a small 

 white grub as it lies curled in its burrow. It is only about one- 

 quarter inch long, and legless, the body being white and the head 

 yellowish brown. The adult beetle is a small snout-beetle about 

 one-fifth inch long, of a dark color, with head and thorax nearly 

 black, and on each wing-cover are three black spots, the middle 

 one being the largest and separated from the others by pale lines. 

 According to Professor Garman the wings are too small to be used 



FIG. 320. The strawberry crown-borer (Tyloder ma fragrance Riley) : a, larva, 

 6, c, beetle enlarged. (After Riley.) 



for flight and this doubtless accounts for the slow spread of 

 the pest. Injury has been reported from Illinois, Kentucky, 

 Missouri, and Nebraska, but as the Iarva3 might be readily shipped 

 in plants, it is quite probable that it has become generally 

 distributed but has not done sufficient injury to attract attention. 

 Life History. The beetles appear during the latter part of 

 summer and fall and hibernate over winter in the soil, emerging 

 early the next spring. The eggs have not been observed, but are 

 undoubtedly laid on the crown between the bases of the leaves 

 in late spring. The larvae develop in the crowns and become full 

 grown by midsummer or August when they pupate in the cavities 



* Tyloderma fragrance Riley. Family Curculionidce. See S. A. Forbes, 

 12th Report 111. State Ent., p. 64; 13th Report, p. 142; H. Garman, Bulletin 

 80, Ky. Agr. Exp. Sta., p. 261. 



