260 



STATE BOARD OF AGRICULTURE. 



STRAWBERRY ROOT-BORER. 

 (Typophorus canellus, Fab.) 



Fig. 12. Strawberry Rout-borer, Ti//jo/>lionis r««e//«.s', adult beetle. (Original.) 



A^ insect, by no means new to Michigan, but which nevertheless is little known, 

 is the strawberry root-borer. Prof. Cook mentions it as occurring at Lansing, in 1880, 

 at which time it was quite a serious pest. During the past summer it has made its 

 presence known in quite an emphatic manner in the southwestern part of the State. 



The full-grown beetle is yellowish-brown in color with ordinarily four black spots 

 upon the wing-covers. These spots vary a good deal in size and form. The prothorax 

 and head are colored reddish-lirown. The entire insect is highly polished and the 

 wing covers are ornamented with longitudinal rows of minute pits, the beetle being 

 about one-eighth of an inch in length. Fig. 12. The larva or grub is about the same 

 size when fully grown ; it resembles a white grub such as is found under .sod, except 

 in size. Fig. 13. It is sometimes foimd in numbers an inch or so beneath the surface 

 of the ground, feeding on the strawberry roots. When the time comes for it to change 

 to the pupal form, it makes a little smooth-walled cell in the soil, where it undergoes its 

 transformations. 



The life history is about as follows: The insects pass the winter as adults. They 

 have been collected hibernating under rubbish near the edge of wooded land.* The 

 adults appear in March, according to Prof. A. J. Cook; they appear in numbers during 

 the first part of May. Eggs are laid and the larvae work on the roots while the adults 

 continue to eat holes in the leaves of the plants until after the fruit is picked, about 

 which time they usually disappear. They again become numerous in August and 

 September, according to Dr. Lintner. 



* Schwarz, Insect Life, Vol. V, p. .3:ir.. 



