Potato Culture. 



21 



the last of August, the potato-worm 

 burrows under the ground, and short- 

 ly afterward transforms into the pupa 

 state, (Fig. 5.) The pupa is often 

 dug up in the spring from the ground 

 where tomatoes or potatoes were 

 grown in the preceding season, and 

 most persons that meet with it sup- 

 pose that the singular jug-handled 

 appendage at one end of it is its tail. 

 In reality, however, it is the tongue- 

 case, and contains the long, pliable 

 tongue which the future moth will 

 employ in lapping the nectar of flow- 

 ers. The moth itself (Fig. 4) was 

 formerly confounded with the tobac- 

 co-worm moth, (Sphinx Carolina, Lin- 

 naeus,) which it very closely resembles, 

 having the same series of orange- 

 colored spots on each side of the ab- 

 domen. 



The gray and black markings, 

 however, of the wings differ percep- 

 tibly in the two species ; and in the 

 tobacco-worm moth there is always 

 a more or less faint white spot, or a 

 dot, near the centre of the front wing, 

 which is never met with in the other 

 species. The potato-worm often feeds 

 on the leaves of the tobacco plant in 

 the Northern States. In the Southern 

 States, in Mexico and the West-In- 

 dies, the true potato-worm is unknown, 

 and it is the tobacco-worm that the 

 tobacco-grower has to fight. The 

 potato- worm, however, is never known 

 to injure the potato crop to any seri- 

 ous extent. 



The Striped Blister-Beetle, 



(Lytta vittata, Fabr.) This insect 

 (Fig. 6) is almost exclusively a south- 

 ern species, occurring in some years 

 very abundantly on the potato-vines 

 in Southern Illinois, and also in Mis- 

 souri, and according to Dr. Harris, it 

 is occasionally found even in New- 

 England. In some specimens the 

 broad outer black stripe on the wing- 

 cases is divided lengthwise by a slen- 



der yellow line, so that, instead of two, 

 there are three black stripes on each 

 wing-case ; and often in the same 

 field may be noticed all the interme- 

 diate grades ; thus proving that the 

 four-striped individuals do not form a 

 distinct species, as was supposed by 

 the European entomologist Fabricius, 

 but are mere varieties of the same 

 species to which the sixth-striped in- 

 dividual appertains. 



The striped blister-beetle lives un- 

 der ground and feeds upon various 

 roots during the larva state, and 

 emerges to attack the foliage of the 

 potato only when it has passed into 

 the perfect or beetle state. 



This insect, in common with our 

 other blister-beetles, has the same pro- 

 perties as the imported Spanish fly, 

 and any of them will raise just as 

 good a blister as that does, and are 

 equally poisonous when taken inter- 

 nally in large doses. Where the strip- 

 ed blister-beetle is numerous, it is a 

 great pest and very destructive to the 

 potato crop. It eats the leaves so 

 full of holes that the plant finally 

 dies from loss of sap and the want of 

 sufficient leaves to elaborate its juices. 

 In some places they are driven off 

 the plants (with bushes) on a pile of 

 hay or straw, and burned. Some have 

 been successful in ridding their fields 

 of them by placing straw or hay be- 

 tween the rows of potatoes, and then 

 setting it on fire. The insects, it is 

 said, by this means are nearly all de- 

 stroyed, and the straw burning very 

 quickly, does not injure the vines. 



The Ash-Gray Blister-Bee- 

 tle, (Lytta cinera, Fabr.) This spe- 

 cies (Fig. 7, male) is the one com- 

 monly found in the more northerly 

 parts of the Northern States, where it 

 usually takes the place of the striped 

 blister-beetle before mentioned. It 

 is of a uniform ash-gray color. It 

 attacks not only the potato- vines but 



