THE STATE ENTOMOLOGIST. 91 



particular species these borers belong, so they have the habit in com- 

 mon, of infesting the roots of his vines. But a more important 

 question presents itself to the thinking mind. Is any danger to be 

 apprehended from these borers, from growing grape-vines and fruit 

 trees among decaying oak stumps ? In my former article, from the 

 testimony of practical vineyardists, I have hinted that there is, and 

 have advised not to plant on land covered with such stumps, or even 

 to use oak stakes, where those made of cedar can be had; and I am 

 glad to be able to say that this advice is well founded. 



As a general rule, the larvae of the Long-horned Boring Beetles 

 either inhabit green and living wood or else decaying and dead wood, 

 the same species never attacking both kinds of wood indiscriminate- 

 ly ; and as I knew that the larva of the Cylindrical Orthosoma fed on 

 rotten pine wood, I thought it very probable that it also fed on rotten 

 oak stumps, and had been confounded by practical men with those of 

 the Broad-necked and Tile-horned species, which it so much resem- 

 bles. This opinion was supported by the fact that it occurred abun- 

 dantly in Union county, South Illinois, in 1861, where there are no 

 pine trees growing, and where, at that period, the so called "poplar" 

 or white-wood was universally used in buildings, in place of pine im- 

 ported from the North ; and I last summer ascertained that it really 

 does breed in rotten oak stumps, as well as in decaying pine, for I 

 found it in the former wood, both in the larva, pupa, and fresh beetle 

 state. But what is still more important I also find that the Broad- 

 necked Prionus, is an exception to the rule above mentioned, and 

 that it breeds as freely in decaying oak stumps as in living roots. For 

 this fact I am indebted to Mrs. Mary Treat of Vineland, N. J., who 

 has sent me specimens of the beetle bred from larvas that are found 

 abundant in the oak stumps in that vicinity. 



Summary.— To sum up the whole matter in a few words, it is ob- 

 vious that we have in Missouri three large boring grubs, which so 

 closely resemble each other, that they cannot be distinguished by any 

 marks which we are yet acquainted with— that the Broad-necked 

 Prionus feeds indiscriminately on the living roots of Apple, Grape- 

 vine, Poplar (and perhaps of several other trees), and on decaying 

 oak stumps, and will travel through the ground from one place to 

 another— that the Tile-horned Prionus not only attacks the Grape- 

 vine, but can subsist on the roots of herbaceous plants, and in all 

 probability will also feed on decaying oak, like the former species ; 

 and finally, that the Cylindrical Orthosoma feeds on decaying pine 

 and oak, but has not yet been found in living roots. From these facts 

 we may deduce the important corollary, that it will not do to leave 

 oak stumps to rot on ground which is intended for a vineyard or 

 orchard — which was the thing to be proved. 



