COLEOPTERA. — SCOLYTIDiE. 353 



An account of a small species found in exotic seeds is given by- 

 Panzer in the Naturforscher, st. 25. ; and I have published the de- 

 scription of a very minute species found burrowing in the bind- 

 ing of a book {Hypothenemus eruditus, Trans. Ent. Soc. Lond. 

 vol. i.). Prof. Peck has also described two species of this genus, 

 Scolytus Pyri and Scolytus Strobi, which destroy the young branches 

 of the pear trees, and the leading branches of the Weymouth pine, in 

 North America {Massach. Agric. Joiirn. January, 1817); and Dr. 

 Heer has described a new species of Tomicus (Bostr. Cembrte H.), 

 together with its larva and pupa, and which attacks the Pinus Cem- 

 bra. {Obs. EntomoL 1836, pi. 5.) 



The larvae of Scolytus destructor {fig. iS. 4.) are thick, fleshy, 

 curved, apod grubs, of a whitish colour, the back much wrinkled; 

 armed with a scaly head and powerful horny jaws ; the upper lip 

 distinct {Jig. 42. 5.); the maxillae short, flat, and ciliated; the 

 maxillary palpi very short, conical, and apparently only 2-jointed 

 {Jig. ¥Z. Q.)\ the labial palpi smaller and conical {Jig. ^^2. 1.). I 

 have found the larvae (in company with the pupae and imago) in the 

 month of August, in the bark of elm trees, and the former alone in 

 November. I have also found Hylesinus Fraxini, in all its states, in 

 the bark of elm trees, in the month of August ; the larva resembling 

 that of Scolytus. 



The larvae of Tomicus {Jig. 42. 14.) and Hylurgus, according to 

 Ratzeburg's figures, are of a form precisely similar to those of Scolytus 

 and Hylesinus Fraxini. The pupte in the two first-mentioned genera 

 are, however, terminated by two spines, whereas the extremity of the 

 body of the pupa of Scolytus is unarmed. 



In the works of Latreille, this group of insects, with several other 

 Xylophagous, Boletophagous, or Fungivorous tribes, is employed to 

 effect the transition between the Curculionidre and Cerambycidae, 

 commencing with those which have the club of the antennae solid, 

 and proceeding, through those families in which the club is more 

 loosely constructed, to the Trogositidiie and Cucujidic, in some of the 

 last of which the antennae arc of considerable length ; the two genera 

 Parandra and Passandra completing the passage. In other and 

 more important points of view, however, this mode of transition 

 cannot be naturally maintained ; the structure of the imago in many 

 of Latreiile's Xylopiiaga, as well as that of their larva-, warranting 



A A 



