138 



Disease of the Plum Tree. 



Vol. VIII. 



tured into a beetle as the spring advances. 

 These statements I have not yet been able 

 to confirm. It seems, however, to have been 

 fully ascertained by Professor Peck, Mr. Say, 

 and others, in whose accuracy full confidence 

 may be placed, that this same weevil attacks 

 all our common stone-fruits, such as plums, 

 peaches, nectarines, apricots, and cherries; 

 Dr. Burnett has recently assured me, that 

 he has seen this beetle puncturing apples; 

 and it is not at all improbable, that the trans- 

 formations of some of the grubs may be re- 

 tarded till the winter has passed, analogous 

 cases being of frequent occurrence. Those 

 that are sometimes found in apples, must not 

 be mistaken for the more common apple- 

 worms, which are not the larvse of a weevil. 

 The Rev. F. V. Melsheimer remarks in his 

 Catalogue, that this insect lives under the 

 bark of the peach tree. Professor Peck 

 raised the same beetle from a grub found in 

 the warty excrescence of a cherry tree, and 

 from this circumstance, named it RhynchfE- 

 nus Cerasi, the cherry-weevil. The plum, 

 still more than the cherry tree, is subject to 

 a disease of the small limbs, which shows 

 itself in the form of large irregular warts, 

 of a black colour, as if ciiarred. Grubs, ap- 

 parently the same as those that are found in 

 plums, have often been detected in these 

 warts, which are now generally supposed to 

 be produced by the punctures of the beetles, 

 and the residence of the grubs. Professor 

 Peck says, that ' the seat of the disease is 

 in the bark. The sap is diverted from its 

 regular course, and is absorbed entirely by 

 the bark, which is very much increased in 

 thickness; the cuticle bursts, the swelling 

 becomes irregular, and is formed into black 

 lumps, with a cracked, uneven, granulated 

 surface. The wood, besides being deprived 

 of its nutriment, is very much compressed, 

 and the branch above the tumor perishes.'* 

 The grubs found by Professor Peck in the 

 tumors of the cherry tree, went into the 

 ground on the 6th of July, and on the 30th 

 of the same month, or twenty-four days from 

 their leaving the bark, the perfect insects 

 began to rise, and were soon ready to de- 

 posit their eggs in healthy branches. 



"In order to account for the occurrence 

 of these insects, both in the fruit and in the 

 branches of the trees, I have ventured, on 

 another occasion, to give the follpwing ex- 

 planation, although it rests only upon con- 

 jecture. The final transformation of the 

 grubs, living in the fruit, appears to take 



* S3e Professor Peck's account of Insects which affect 

 Oaks and Cherry trees; with a plate; in the " Massa- 

 chusett's Agricultural Repository and Journal." Vol. 

 V. p. 312. 



place at various times during the latter part 

 of summer and the beginning of autumn, 

 when the weevil, finding no young fruit, is 

 probably obliged to lay its eggs in the small 

 branches. The larvse or grubs from these 

 eggs, live in the branches during the win- 

 ter, and are not perfected till near the last 

 of the following June. Should the fall of 

 the fruit occur late in the autumn, the de- 

 velopment of the beetles will be retarded 

 till the next spring; and this I suppose to 

 be the origin of the brood which stings the 

 fruit. These suggestions seem to receive 

 some confirmation from the known habits of 

 the copper-coloured plum-weevils of Europe, 

 which, 'in default of plums, make u.se of the 

 soft spring shoots of the plum and apricot 

 trees.' — (Roller's Treatise, p. 23-^.) In cases 

 like these, we see the care of the Creator 

 for some of the least of his creatures, which 

 He has wisely provided with variable in- 

 stincts, enabling them to accommodate them- 

 selves to the difficulties of the situation in 

 which they may happen to be placed, and 

 thus, even in unfruitful seasons, to provide 

 for a succession of their kind. 



"The following, among other remedies 

 that have been suggested, may be found 

 useful in checking the ravages of the plum- 

 weevil. Let the trees be briskly shaken or 

 suddenly jarred every morning and evening, 

 during the time that the insects appear in 

 the beetle form, and are engaged in laying 

 their eggs. When thus disturbed, they con- 

 tract their legs and fall , and, as they do not 

 immediately attempt to fly or crawl away, 

 they may be cauiiht in a sheet spread under 

 the tree, from which they should be gath- 

 ered into a large wide-mouthed bottle or 

 other tight vessel, and be thrown into the 

 fire. All the fallen wormy plums should be 

 immediately gathered, and, afler they are 

 boiled or steamed, to kill the enclosed grubs, 

 they may be given as food to swine. The 

 diseased excrescences should be cut and 

 burned every year before the last of June. 

 The moose plum-tree, Prunits Americana, 

 which grows wild in Maine, seems to escape 

 the attacks of insects, for no warts are 

 found upon it, even when growing in the 

 immediate vicinity of diseased foreign trees. 

 It would, therefore, be the best of stocks 

 for budding or engrafting upon. It can 

 easily be raised from the stone, and grows 

 rapidly, but does not attain a great size." 



Duvir.ARD has calculated that the intro- 

 duction of vaccination by Jenner, has in- 

 crersed the average length of life to the hu- 

 man po lulation, by three years. — Cambridge 

 Miicellany, Oct., 1843;—;?. 123. 



