464 



FAMILY SCOLYTIDAE 



on occasions, to prepare the whole of the egg-j^allery and lay all her eggs. 

 The eggs hatch out within twenty-four to forty-eight hours, and the larvae 

 of the first-laid eggs have already commenced to eat out the larval galleries 

 before the mother has finished laying the eggs at the top of the galleries. 

 In the case of most of the Indian monogamous bark beetles known, the 

 mother beetle remains alive during most of the period the grubs are reaching 

 full growth, moving up and down her egg-gallery, which is kept quite free 

 of wood-dust, or remaining in the entrance-tunnel in the bark, which she 

 thus effectually blocks up as with a plug, preventing predaceous insect foes 

 from entering it to get at and devour the larvae, or to deposit their eggs in 

 the egg-gallery from which hatch out predaceous grubs. The whole of the 



Fk;. 307. — Kgg and larval galleries of Scolytiis major, Steb., in deodar. 



bark and wood-dust eaten out in making the entrance-tunnel and egg- 

 gallery are ejected through the orifice in the bark, and may often be found 

 in small patches on the outer bark beneath the entrance-hole. 



Coming now to the larvae. As soon as they hatch out from the eggs 

 thev devour the small mass of soft wood-powder with which the mother 

 surrounded the e\:^\:^, and then commence tunnelling more or less directly 

 away from the egg-gallery. These galleries eaten out by the larvae groove 

 the bast or both bast and sapwood, and increase in size with the growth of 

 the grubs. They keep their main direction, but serpentine about to some 

 extent. Those taking off from the centre of the egg-gallery are more or less 



