plant. I find no insects but these on the plants, which, after be- 

 ing girdled by them, turn yellow and die. The insects are not 

 near as numerous now as a few weeks ago." — C. V. R. 



Wood-boring Coleoptera. — There are many Coleoptera of 

 various families which live in the galleries made by other species 

 in the hard wood of trees. Thus the galleries of Mallodon and 

 other large Cerambycidae, form the home of many other species 

 after the original owner has left them. If these inquilines are 

 much smaller than the maker of the gallery, there is, of course, 

 no difficulty in recognizing them as inquilines that did not make 

 the gallery themselves. If, however, they are nearly of the same 

 size as the original burrower, it is difficult to decide whether or 

 not the galleries they inhabit have been made by them. Thus Mr. 

 Eichhoff, in his excellent work on European Scolytidae, suspects 

 'that the genus Platypus uses the galleries made by other beetles. 

 My own experience in the South, with the common Platypus com- 

 positus is as follows: When found in the thick bark of pine 

 stumps, the larvae doubtless bore themselves, as there is no other 

 beetle found in their company which makes such smooth and 

 straight galleries. If, however, they occur in hard wood, such as 

 oak, hickory, hackberry, etc., the case appears to be different, and 

 seems to confirm Mr. Eichhoff' s statement, as I found them always 

 associated with true boring insects, viz., Colydium lineola and So- 

 syius costatus. The galleries of these three species are undistinguish- 

 able, and it appears to me very probable that Platypus simply uses 

 the old galleries made by the two Colydiid beetles just mentioned. 

 The Histerid genus Teretrius is another instance of this sort 

 where the inquiline can be readily mistaken for the maker of the 

 gallery, but in this case the Teretrius is simply parasitic on Ptil- 

 mus and other boring insects. I also would call attention to the 

 fact that Professor Riley discovered the larva of Hemirhipus fas- 

 cicularis to be parasitic on Cyllene picta, 1 in whose galleries it was 

 living. As the two species are of about the same size, the Hem- 

 irhipis might be readily taken for a true wood-borer. 



Another observation bearing upon this subject I had recently 

 occasion to make in a street in Washington, D. C. There was 

 an old maple tree perforated on one side with numerous holes, 

 made, I presume, by an Elaphidion or some other average-sized 

 J-erambycid. The burrows had evidently long since been deserted 

 t>y the original makers, but I saw protruding from four or five of 

 them the heads of Strong vlittm tenuicolle. Upon investigation I 

 tound that the beetles had died in the vain effort to escape from 

 tlie gallery, the entrance being much too small to let the body 

 pass through. Now I know by experience that Strongylium is not 

 a true boring insect, and lives only in the very soft wood of decay- 

 ,n g trees, especially of oak. It appears to me probable, there- 



,de Ist Report U. S. Entomological Commission, p. 304. 



