FAMILY SCOLYTIDAi: 



491 



sides, is grooved out, and in this two beetles, 

 a male and female, are always to be found ; 

 and this is probably the pairing-chamber. 

 After pairing the male leaves the chamber 

 by the hole of entrance, and the female 

 commences boring her egg-gallery. This 

 is merely a straight continuation of the 

 pairing-chamber, and is always parallel 

 to the longitudinal axis of the tree. Small 

 recesses are eaten out on either side close 

 together all up this gallery, and an e^g laid 

 in each. The first eggs hatch out before the 

 female has completed her gallery and egg- 

 laying, so the egg-stage is evidently a short 

 one— lasting but a few days at most. The 

 female blocks up each recess with wood-dust 

 after laying an egg in it, probably to provide 

 a first meal for the newly hatched larva. 

 The egg-gallery is kept quite free of wood- 

 dust. An examination of old galleries will 

 show that the larvae bore away from the egg- 

 gallery in a radiating manner, the pattern 

 formed by their collective galleries approach- 

 ing an ellipse. When full-fed the larvae 

 enlarge the end of their galleries and pupate 

 in these chambers. When mature the beetle 

 bores its way straight out of the tree by a 

 hole through the bark. The length of the 

 egg-gallery is five-eighths of an inch to two 

 inches, with a breadth of a quarter of an inch 

 or less. Length of larval galleries one-third 

 to one and a quarter inch. Breadth one- 

 eighth inch at top and one-sixteenth inch 

 at base, where they take off from egg-gallery. 

 The number of eggs laid by the beetle averages 

 twenty- four. The plan of the gallery is very 

 like that of S'. siicalikensis, shown in fig. 19. 



I consider it probable that there are at 

 least three generations of this beetle in the 

 year — and perhaps four. Some green Ano- 

 geissus poles felled in April and left lying in 

 the forest w^ere examined on 6 August. They 

 were found to have been attacked from top 

 to bottom by this beetle since they had been 

 felled. The insects had laid their eg£?s in 



M 



Fig. 323. — Aitoi^eissits latifolia pole 

 infested by Sphaerolrypes coimba- 

 toreiisis, Steb., showing the exit-holes 

 of a matured generation of beetles. 

 Coimbatore, Madras. August 1902. 



