80 



"5. Cri/phnlus binocbihm, Ratzcb., Janson (Ent. Annual for \8f)7, p. 8;<, Plate, 

 fig. 9). Of thisll have succeeded in capluiing about a dozen specimens from the same 

 tree which yielded it ine last year, and which, I fear, are all I shall be able to secure, 

 as the tree is under condemnation, and will probably be consigned to the hearth ere 

 the close of the next winter. 



"t). Scoli/tus rtigulosus (Koch), Ratzeb. die Forst. Insecten, i. 187 (1837). Reared 

 in considerable numbers from the dead branches of a pear tree, gathered by Mr. 

 Groves in his garden at Lewisham, and not hitherto recorded as British. The ques- 

 tion has been more than once discussed in this room whether the Scolyti attack 

 healthy and vigorous trees, or whether they select as a nidus such trees only as are 

 already diseased, — whether, in fact, they are the primary or merely an accessory cause 

 of the devastation which has been attributed solely to them. Each view has found 

 warm and able advocates, but I believe the question still remains open, nor can I 

 aspire to close it, but I think, as far as the species now under consideration is con- 

 cerned, we may fairly conclude that, under ordinary circumstances, its pabulum con- 

 sists of dead wood, since Mr. Groves informs me that it is on the upper dead branches 

 alone that the insect is to be found, no trace of it being discernible on any other part 

 of the tree; and, in fact, the branches which he has placed in my hands, and from 

 which the specimens now exhibited were reared, present every appearance of having 

 been destitute of vitality for several years. The present species, however, departs con- 

 siderably in habit from that of its congeners which I have had an opportunity of 

 studying (destructor, Oliv., intricatus, Ratzeb., and multistriatus, Marsh., Ralzeb.), 

 whose larvie subsist chiefly on the inner bark, occasionally only attacking the sap-wood 

 in their progress, and, when full-fed, assuming the pupa state at the end of the bur- 

 row, or in a very shallow cell excavated in the sap-wood ; whilst, on the other hand, 

 the larvae of the insect now before us appear to derive their chief sustenance from the 

 solid wood, into which they penetrate deeply, the outer surface presenting only faint 

 traces of erosion. 



"The genus Scolytus, first instituted by Geofi'roy, but to which our continental 

 brethren persist in applying the more recent generic appellation of Eccoptogaster, pro- 

 posed by Herbst, at present contains upwards of a dozen described European repre- 

 sentatives, all of which subsist upon trees indigenous to or generally cultivated in this 

 country. Of these five only are at present known to me as natives, viz., — 1. S. Ralze- 

 burgii, mihi, Eul. Annual for 1856, p. 87 (destructor, Eric, Ratzcb., nee Oliv.), fre- 

 quenting the birch, and probably confined to the northern portions of our island ; 

 2. S. destructor, Oliv,, abundantly distril)uted throughout the southern and central 

 portions of England, and which attacks the elm, confining itself, however, to the trunk 

 and large limbs ; 3. S. multistriatus. Marsh., Ratzeb., also peculiar to the elm, where 

 it is occasionally found in company with the preceding, but more generally alone and 

 in the small branches; 4. S. intricatus, Ratzeb., a denizen of the oak, and, according 

 to nay experience, attacking the branches only ; 5. S. nigulosus, Ratzeb., the species 

 now before you, aud which, as we have seen, inhabits the smaller branches of the pear 

 tree; on the Continent, Ratzeburg informs us, it occurs in plum and a])ple trees. 

 Ratzeburg (/. c.) has thus divided the genus : — 



§ 1. Abdomen beneath, in at least one of the sexes, with tubercles or teeth. 

 § 2. Abdomen beneath without tubercles or teeth. 



Of the ascertained British species, Ratzeburgii, destructor and multistriatus pertain 



