72 DR. HARRIS'S REPORT. April, 



bursts its membranous shroud, and crawls to the surface, where it 

 becomes, from a grovelling worm of the earth, an animated tenant of 

 the air. Thus the various changes, from the egg to the full develop- 

 ment of the perfect insect, are consummated in the space of one year. 



Our insectivorous birds undoubtedly consume many of the rose-bugs 

 in the perfect and larva state, and deserve to be cherished and pro- 

 tected for their useful habits. The perfect insects are eaten greedily 

 by domesticated fowls, and, when exhausted and fallen on the ground, 

 become food for other animals and insects, particularly ants. Dr. 

 Green informs us that a species of dragon-fly, or devil'sneedle, 

 (LiBELLULA,) also destroys them. In France, a large insect, call- 

 ed vma?^mr, (Carabus aurataSi L.) devours the female Mclolontha 

 vulgaris at the moment when she is about to deposit her eggs. I 

 have taken one specimen of this fine Carabus in Massachusetts, and 

 we have several other species which are equally predaceous, and which 

 probably contribute to check the increase of our native species of 

 Melolontha. According to Dr. Green, the insect, which he calls 

 the enemy of the cut-worm, prays also upon the grubs of the Melo- 

 lontha. Tiiis predaceous insect is the larva of a species of Carabus. 



Various remedies for protecting vegetation from the ravages of the 

 melolontha have been suggested. The most useful are to strew air- 

 slacked lime on the plants exposed to their attacks, or to cover them 

 with millinet. Great numbers may be collected and destroyed by 

 hand, and, were this made a general pursuit, it would be productive 

 of considerable benefit. " Eighty-six of these spoilers," says Dr. 

 Green, "were known to infest a single rose-bud, and were crushed 

 with one grasp of the hand . " Suppose, as was probably the case, one 

 half of them were females ; by this destruction about 800 eggs were 

 prevented from becoming matured. The rose-bugs may be shaken or 

 brushed from plants into tin vessels containing a little water, and after- 

 wards committed to the flames, or killed by scalding water. The 

 causes that contribute to the natural increase and diminution of these 

 and other insects, are not sufficiently understood. Of the fact we 

 are assured, that various destructive insects occasionally diminish in 

 numbers, and nearly disappear. This has been the case with rose- 

 bugs, which have sensibly decreased during several years past ; — 

 now, then, is the time when our efforts for their extermination would 



