FAMILY SCOLYTIDAE 



point ; from the latter a median narrow longitudinal smooth shining space runs to base ; the 

 rugosities and punctures finer on either side of this smooth space than in the anterior half. 

 Elytra shining orange-brown ; base, basal half of suture, and lateral edges black ; rather flat, 

 the punctures fine and not very close together ; the apical depression set with three longitudi- 

 nally placed blunt teeth, the upper ones nearer suture than the outer margin ; upper one 

 small and inconspicuous, the next but slightly larger, the apical one more prominent, pointed, 

 and placed medianly. Under-surface with scattered yellowish pubescence ; antennae and legs 

 rufous brown. Length, 2.75 mm. $. The front of head is smooth, flat, without depressions, 

 with a transverse raised ridge, thickest medianly, on posterior margin ; punctures slightly 

 rugose. Thorax slightly shorter and broader than in the female, the rugosities slightly stronger 

 anteriorly and the punctures finer in the basal half. Elytra dark red-brown or black, more shining 

 and more convex than in $ , the punctures finer and rather scattered, the apical depression longer 

 and less vertical and deeper than in $ ; the three longitudinally placed teeth much longer and 

 sharper, the uppermost smallest, turned inwards ; the median one longest, set upwards and 

 inwards ; the apical one sharp, curved inwards, smaller than the median one. Length, 2 mm. 

 Th- size of both males and females varies to a slight extent (pi. xlviii, figs. 3, 3 c). 



Larva. A minute, curved, rather corrugated, white, legless grub with a canary- 

 yellow head. 



Pupa White, having the shape of the beetle. X 8 



This Pitoygenes commences to lay the first generation of & 



eggs of the year in April. The beetles are 

 Life History. not particular as to the part of the bark of 

 the tree they bore in through, and appear to 

 bore through an exposed flake of outer bark as often as they 

 seek a crevice to shelter themselves whilst at work. Doubtless 

 numbers are seized and consumed by such enemies as the 

 Thanasiinus beetle and others whilst they are at work in the 

 rirst stages of tunnelling into the tree. The male bores the first 

 tunnel down to the sapwood and eats out in this a pairing- FIG. 357. 

 chamber. He is aided in the latter part of the work of con- coniferae, 

 structing this chamber by one or more of the females which Steb. 

 enter to him, the pairing-chamber being finally as much as ' 



3 mm. across (cf. fig. 358). The first female to enter to the N.w. 

 male does so by enlarging the tunnel of the male, since the female 

 is of larger size. The females subsequently entering either do so by the 

 original tunnel of the male or eat out separate tunnels of their own 

 which hit off the lower part of the male's entrance-tunnel or the pairing- 

 chamber direct. 



As many as five females (and occasionally six) enter and pair with 

 one male. Each female in turn as soon as fertilized bores away from the 

 pairing-chamber, eating out a gallery which curves in one direction only, 

 from right to left. Each of the five female galleries, which may be as 

 much as 13 mm. long, is started in a different direction, so that when all the 

 galleries are finished the whole thing has a stellate appearance (cf. fig. 358). 

 Whilst making her egg-gallery the female eats out small notches or de- 

 pressions in the margin, mostly on the outside of the curve, and places 

 an egg in each. About ten to twelve eggs are laid in each gallery, this 



N N 2 



