1900] PLUM SAP-WOOD BEKTLE. 71 



ments succeeding, which are transversely wrinkled above, and less 

 markedly so below, the upper and under portions being separated by a 

 projecting row of enlargements, or corrugations, at the lower part of 

 each side. The length of the largest specimen when extended was 

 somewhat more than the eighth of an inch from the top of the thorax 

 above the deflexed head to the extremity of the tail ; others were about 

 half to two-thirds of this length. 



The development to pupal condition in the small amount of infested 

 bark sent me was first noticeable on April 25th. On this date, on 

 examining the larvas which had been lying in "frass," or powdery 

 decayed matter, just beneath the bark, I found that one had completed 

 the change to pupal state. It was now rather less than one-eighth of 

 an inch in length, and of a palish yellow tint which might be almost 

 described as white. The various limbs folded beneath the body, the 

 wing-cases only reaching to rather more than half the length of the 

 abdomen, and very nearly approximating, but not quite touching, at 

 the bluntly formed tips, and the transverse divisions of the segments 

 of the abdomen showed plainly on the upper surface, excepting near 

 the thorax. 



On May 3rd and 4th I found a developed beetle, and also a well- 

 developed pupa, and a beetle with shining black thorax and wing-cases, 

 with punctures arranged in single rows between the striae, lying in 

 their pupal cells a little within the outside of the bark. 



But with regard to the species of Scolytus, of which I observed the 

 larva, much as I wished to ascertain it beyond doubt, I cannot take 

 on myself to say with certainty that they were of jniini. The larvae 

 of Scolyti greatly resemble each other, and from the chief presence of 

 pruni, and the measurement of the pupa above mentioned, it seems 

 probable that they were of this species. Still pnmi and rugulosiis may 

 be found together, and I had the annoyance, after my careful obser- 

 vation, of one M?aiiistakable riujulosus making its appearance ; therefore 

 I give the above descriptions, certainly beimj of maggots of one or other 

 of these "Plum-bark Beetles," and possibly of practical use in con- 

 nection with further observations. 



So far as I am aware, this species is rare in this country ; at least 

 I have never before the past season received any report of injury 

 caused by it, nor do I find descriptions of it as being definitely injuri- 

 ous. In continental orchard growmg, however, it is recognized as 

 doing much harm. By collating such amount of information as is 

 given regarding this Scolytus ( = Eccoptogaxter) pruni by the writers 

 referred to below,-''- it appears that it attacks the large stems as well 



* See ' Die Europaischen Borkenkiifer,' von W. Eichhoff, pp. 154, 155 ; ' In- 

 sektenkunde,' von Dr. E. L. Taschenberg, pt. ii. p. 245 ; ' PHanzenfeinde,' von J. 

 H. Kaltenbach, p. 154. 



