FAMILY SCOLYTIDAE 



being apparently the number laid per female beetle. 

 The larvae on hatching out bore away from the 

 mother gallery, their galleries curving in an irregular 

 manner and being from 10 mm. to 20 mm. in length. 

 They feed chiefly in the bast layer, so that their 

 galleries do not groove the sapwood. When full- 

 fed the larvae eat out a depression at the end of 

 their gallery in the sapwood and pupate in this. 

 Fig. 358 shows pairing-chambers, egg-galleries, and 

 pupating-chambers in the sapwood of a deodar 

 branch. 



The beetles when mature tunnel through the 

 bark above them and escape from the tree. 



The insect passes through four generations in 

 the year and a partial fifth. The eggs of the 

 first generation are laid, as I have said, in April, the 

 'beetles from these eggs appearing early in June. 

 From the eggs laid by them a second generation of 

 beetles appears at the end of July, a third in Sep- 

 tember, and the fourth towards the end of October 

 or beginning of November. These beetles lay eggs 

 which produce the larvae which pass through the 

 winter in this stage in the trees. 



The presence of this beetle in a forest can easily 

 be recognized in the smaller 

 Damage Committed dead branches and twigs litter- 

 in the Forest. ing the ground. If these latter 

 are examined they will be found 



to be covered with sharply cut definite patterns (I 

 am alluding to branches from which the bark has 

 fallen off). If these markings are examined they 

 will be seen to consist of from four to six arms or 

 galleries radiating from a common central depres- 

 sion ; each gallery curves away from the central 

 chamber, and is marked on one side with little 

 recesses arranged in a regular, systematic manner. 

 The central depression is the pairing-chamber, each 

 of the radiating arms an egg-gallery made by a 

 female, and the little recesses, which are from six to 

 nine in number and made on one side of the gallery 

 only, formerly each contained an egg. If the bark of 

 this twig could be examined on the inner side it would 

 show the larval galleries giving off more or less at 

 right angles to the egg-gallery, one starting from 

 each of the nicks and winding round the twig. At 



FIG. 358. Part of a 

 deodar branch showing the 

 central pairing - chamber 

 made by the male beetle of 

 Pityogenes coniferae, and 

 the star-shaped egg-galleries 

 with notches on their sides 

 made by the female beetles. 

 N.W. Himalaya. 



