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SOME OF THE MORE IMPORTANT INSECTS ATTACKING 

 NUT TREES IN ILLINOIS. 



« « 



TV. P. Flint, Entomologist — Illinois. 



Several years ago, the Natural History Survey conducted a forest 

 insect survey of Illinois. During the course of this survey, mtive 

 woodlands were examined for insect injury in all part of the state. 

 In the course of this work which covered some two years time, many 

 examinations were made of hickory, pecan, black walnut, some chestnut 

 trees, and other nut bearing trees. The insects that attack nut bearing 

 trees in the latitude of Illinoi.'j may be grouped in three classes, 1st 

 those that attack the trunk or branches of the tree, 2nd', those that 

 attack the foliage and blossoms, and 3rd, those that attack the 

 fruit or nuts. 



Hickory Tiger Beetle. Of the insects that attack the trunk, one 

 of the most common and destructive insects to hickory and pecan 

 throughout the state, is the Hickory Tiger Beetle, or Tiger Borer. 

 This insect is common in all parts of the state, causing injury mainly 

 to the young hickory trees when they are from two to six inches in 

 diameter. The adult beetles, which are over an inch long, are of a 

 })urplish-gray color, with somewhat mottled wing covers, make their 

 appearance during June and July. The females make small circular 

 pits in the smooth bark of the branches or main trunk of young trees, 

 and in the centers of these pits deposit their eggs. There are generally 

 several pits at inch or half inch intervals along one section of the 

 trunk. By fall, the young larvae hatching from the eggs have fed 

 under the bark to such an extent as to cause a cracking of the bark. 

 Strings of brown castings will be pushed out from the points where 

 tlie insects arc working under the bark. 



During the second year, the beetles burrow in the wood of the 

 tree, often seriously weakening the trunk or branches, and emerge in 

 June or Jiilv of the second season as the adult beetles above des- 



