1906 ENTOMOLOGICAL SOCIETY. 123 



FOREST ENTOMOLOGY. 



By E. J. Zavitz, Ontario Agricultural College, Guelph. 



Destruction of the forest by insects is a problem in which the forester 

 is very much interested. The depredations of these small foes are being 

 carried on to a greater extent than we realize, and every season sees large 

 quantities of timber being injured or destroyed by insects. 



Entomology is of vast importance to the forester, and he should at least 

 become acquainted with the appearance and life history of the important 

 forest insects. In universities and forest academies in Germany where 

 forestry is taught, special courses are given in Forest Entomology. The 

 German forester carries in his pocket a small calendar in which he takes 

 notes and in which is recorded what to look for during each month of the 

 year. It is interesting to note that one of the subjects, taking greatest space, 

 is that regarding the insects for which to be on the lookout during each 

 month. 



Insects damage forests in many ways and at various stages. The fruit, 

 the tender seedling, and the roots, foliage and wood of the mature tree all 

 have their enemies. In fact, during its whole life history the tree is subject 

 to attacks. 



;Fig. 59. Balaninus~beetle, grub, pupa tQ 

 and infested nuts. 



In collecting the acorns of Red Oak for seed I have found that a large 

 percentage of the acorns are destroyed by one of the Curculionidse. Two 

 bags of acorns, which had been allowed to stand over night, were surrounded 

 by footless grubs one centimetre in length. These are probably the larvae 

 of Balaninus quercus. It was estimated that about forty per cent, of these 

 acorns were destroyed by this insect. The female insect bores a hole into 

 the acorn and then drops in the egg which develops into the grub-like larva. 

 This larva feeds upon and in most cases destroys the acorn. After the 

 acorn falls to the ground in autumn the larvae go into the soil and transform, 

 coming forth the following spring. (Eig. 59 represents a closely allied 

 species which attacks Filberts). 



This shows that this insect alone is a strong factor against the repro- 

 duction of red oak under natural conditions. Curculios also infest the seed 

 of such trees as basswood, hickory and chestnut. 



During the seedling stages of the tree the insects carry on their work. 

 The cutworm has given some trouble in cutting the white pine seedlings 

 in the nursery beds. A number of small white ash were found to be dying, 

 and upon examination it was found that the roots were attacked by the wire- 

 worm or larvae of the click-beetle. The larvae were hardly discernible at first 



