INSECTS. 223 



on the leaves before they began to gather into heads. He said 

 it not only killed the worms, but helped the leaves to fold one 

 upon the other, and make good heads. I suggested to him 

 that a solution of salt would do better. He seemed to know 

 nothing about that, but he knew that sprinkling salt over the 

 heads two or three times in the season would protect them 

 from worms, and so he applied it in that way. I have never 

 used it, but I intend to do so. 



Mr. Day. I should like to have Prof. Smith give the rea- 

 son why dust kills these worms, as Prof. Johnson has sug- 

 gested. 



Mr. Gold, And at the same time take some little notice 

 of that foul-looking worm or bug. 



Mr. Smith. This foul-looking worm which several gentlemen 

 have described in somewhat different ways, is the young of 

 the striped potato-beetle. Perhaps I should have described its 

 habits more particularly. The beetle was well described (by 

 Mr. White) as a little bigger than the cucumber-beetle, and 

 with the stripes a little darker. The foul-looking worm which 

 the same gentleman mentioned was the young of the same 

 insect. The different stages of this beetle are by far the 

 commonest insects on the potato in New England. The bee- 

 tles come out of the ground the last of May or early in June 

 and at once attack the leaves of the potato, usually collecting 

 among the young leaves at the top of the vines. When taken 

 between the fingers they make a creaking sound. The fe- 

 males soon lay their eggs, which are oval, bright yellow, and 

 glued to the leaves in little clusters of half a dozen or so. 

 The little grubs, which are soon hatched from these eggs, 

 grow rapidly and devour the leaves. They are rather short and 

 thick and have a pair of legs on each of the first three rings of 

 the body. After eating the leaves they cover themselves with 

 their own excrement. The anus is on the upper side of the 

 last ring of the body, and as the excrement is expelled and 

 falls upon the back of the grub, it is pushed forward by the 

 motion of the body till the whole back is covered with a filthy 

 mass, which undoubtedly protects their soft bodies from their 

 enemies. They always move backward while eating, devour- 



