FAMILY SCOLYTIDAE 577 



Scolytus (Eccoptogaster) minor, Stebbinfi^. 



Referrncks. — Stebbiiig, Ind. For. Mem. Zool. Ser. vol. i, pt. ii, p. 22 ; JJjparL Notes, vol. i, p. 207. 



Habitat. — Deodar Forests of the North-West Himalaya. 



Tree Attacked.— Deodar {Cedrus deodara), North-West Himahiya. 



Beetle.- This insect greatly resembles the larger Scolytus, the eggs, larvae, and pupae 

 presenting no diti'erences of importance. The beetle has the following differences in external 



characters : — 

 Description. Smaller than major, which it greatly resembles, the elytra usually 



darker in colour to nearly black. The front of head presents dif- 

 ferences. In the female there is no median longitudinal line or striate area or median 

 depression near basal margin on vertex ; the front is uniformly and rather coarsely rugose 

 (at times almost tuberculate), except on \ertex, which is punctate ; a few yellowish hairs over 

 mouth. Prothorax constricted and rounded anteriorly, the thickly rugose and punctate area 

 on the anterior margin broader than in tnajor and not interrupted by a longitudinal median 

 smooth area, the disk less shining than in tnajor and the punctures finer and more numerous. 

 Elytra differ from major in having the punctations not confluent and very much smaller ; they 

 are more regularly spaced, but wider apart in the rows, becoming finer apically ; the serrate 

 margins of apical fourth more marked. The first segment of abdomen less rugose-punctate 

 than in tnajor, the posterior margins of third and fourth segments thickened throughout their 

 entire length without a median or posterior tubercle. Length, 2.5 mm. to 3 mm. In pi. Ivii, 

 figs, a-d, ai, bi, di, show the larva, pupa, and beetle, enlarged and natural size. 



Save in size and the appearance of the front of the head and the disposition of the 

 punctures on the thorax, this species is scarcely distinguishable from major. The difference 

 in size and the other points of divergence appear, however, to be constant. 



The method of oviposition and the plan of the egg and larval galleries 



resemble those of 5. major, the differences being that 



Life History. the egg-gallery is shorter in length, being rarely over 



an inch long and usually even less, and the number of 



eggs laid averaging about thirty-five to forty, i.e. from seventeen to twenty 



are deposited on each side of the egg-gallery. 



The time taken to pass through one life-cycle and the number of gene- 

 rations pissed through in the year resemble those of 5. major. 



Bracon sp. — Some nearly mature species of a Bi-acon fly were found 

 in a deodar sapling at the end of the first week in June in the pupating- 

 chambers at the end of the larval galleries of the bark- 

 Parasitic Insect. borer Scolytus minor. The tree was growing at a low 

 elevation, and the eggs were probably laid at the 

 beginning of May. The insects were too immature to identify further with 

 any certainty. These flies are evidently parasitic upon the larvae of the 

 small Scolytus beetle. The eggs are laid by the female insect, who probably 

 pierces through the bark and deposits them in the larval tunnel, or she meiy 

 place them in the entrance-tunnel. The young maggot feeds upon the 

 larva, and does not kill it until it has reached its full growth and gnawed 

 out its pupal chamber. 



The other insects mentioned under Scolytus major are predaceous upon 

 this scolytid. 



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