THE PEAK SLUG- WORM. 



finish this business and disappear within the space of three weeks. Their eggs 

 are placed, singly, within little semicircular incisions through the skin of the leaf, 

 and generally on the lower side of it. The flies have not the timidity of many 

 other insects, and are not easily disturbed while laying their eggs. On the four- 

 teenth day afterwards, the eggs begin to hatch, and the young slug-worms con- 

 tinue to come forth from the fifth of June to the twentieth of July, according as 

 the flies have appeared early or late in the spring. At first the slugs are white ; 

 but a slimy matter soon oozes out of their skin and covers their backs with an 

 olive-colored sticky coat. 



They have twenty very short legs, or a pair under each segment of the body, 

 except the fourth and the last. The largest of the slugs are about nine-twentieths 

 of an inch in length when fully grown. 



The head of a dark chestnut color, is small, and entirely concealed under the 

 forepart of the body. 



They ai'e largest before, and taper behind, and in form somewhat resemble 

 minute tadpoles. 



They have the faculty of swelling out the forepart of the body, and resting 

 with the tail up. 



These slugs live mostly on the upper side of the leaves, and eat away the sub- 

 stance, leaving only the veins and skins untouched. The trees attacked by them 

 are forced to throw out new leaves during the heat of the summer; this unseason- 

 able foliage, which should not have appeared until the following spring, exhausts 

 the vigor of the trees and cuts off the prospect of fruit. 



The slug-worms come to their growth in twenty-six days, during which period 

 they cast their skins five times. After the last skin is thrown ofi", they no longer 

 retain their slimy appearance and olive color, but have a clear yellow skin, entirely 

 free from viscidity. They change also in form and become proportionably longer, 

 and their head and the marks between the rings are plainly to be seen. In a few 

 hours after this change, they leave the trees, and having crept or fallen to the 

 ground, they burrow to the depth of from one inch to three or four inches in the 

 ground, according to the nature of the soil. By moving their bodies, the earth 

 around them becomes pressed equally on both sides, and an oblong oval cavity is 

 thus formed, and is afterwards lined with a sticky and glossy substance, to which 

 the grains of earth closely adhere. Within these little earthen cells or cocoons 

 the change to chrysalids takes place ; and in sixteen days after the descent of 

 the slug-worms, they finish their transformations, break open their cells and crawl 

 to the surface of the ground, where they appear in the fly form. These flies 

 usually come forth between the middle of July and the first of August, and lay 

 their eggs for a second brood of slug-worms. The latter come to their growth, 

 and go into the ground in September and October, and remain there till the fol- 

 lowing spring, when tliey change to flies. 



It seems that all do not finish their transformations at this time ; some are 

 found to remain unchanged in the ground till the following year ; so that if all 

 the slugs of any one hatch should happen to be destroyed, enough from a former 

 brood would remain in the earth to coiuinue the species. 



Ashes and quicklime, sifted on the trees l)y means of a sieve fastened to a pole, 

 was recommended by the late Hon. John Luwell, of Roxbury, for the destruction 

 of the pear and cherry slug-worm, and it is found to answer the purpose. 



