Potato Culture. 



about a fortnight before it emerges in 

 the perfect beetle state, and the se- 

 cond brood stays under ground all 

 winter, and only emerges at the be- 

 ginning of the following June. 



The perfect beetle (Fig. u)is of 

 a pale yellow color, with three black 

 stripes on its back, and bears a strong 

 resemblance to the cucumber-bug, 

 (Diabrotica vittata, Fabr. Fig. 12.) 



From this last species, however, it 

 may be distinguished by its somewhat 

 larger size, and by the remarkable 

 pinching-in of the thorax, so as to 

 make quite a lady-like waist there, or 

 what naturalists call a " constriction." 

 The female, after coupling, lays her 

 yellow eggs (Fig. ioX) on the under 

 surface of the leaves of the potato 

 plant. The larvae hatching, when 

 full grown descend into the ground, 

 where they transform to pupae (Fig. 

 10, c) within a small oval chamber, 

 from which in time, the perfect beetle 

 emerges. 



This insect in certain seasons is a 

 great pest in the Eastern and Middle 

 States, but has never yet occurred in 

 the Mississippi Valley in such num- 

 bers as to be materially injurious. 



The Cucumber Flea Beetle, 



(Haltica cue umer is, Harris.) This 

 nimble minute beetle (Fig. 13) belongs 

 to the flea-beetles, (Haltica family,) 

 the same sub-group of the leaf-beetles 

 (Phytophaga] to which also appertains 

 the notorious steel-blue flea-beetle 

 (Haltica chalybea, Illiger) that is such 

 a pest to the vineyardist. Like all 

 the rest of the flea-beetles, it has its 

 hind thighs greatly enlarged, which 

 enables it to jump with much agility. 

 It is not peculiar to the potato, but 

 infests a great variety of plants, includ- 

 ing the cucumber, 'from which it de- 

 rives its name. It eats minute round 

 holes in the leaf of the plant it infests, 

 but does not always penetrate entire* 

 ly through it. 



The larva feeds internally upon the 

 substance of the leaf, and goes under 

 ground to assume the pupa state. It 

 passes through all its stages in about 

 a month, and there are two or three 

 broods of them in the course of the 

 same season. This is emphatically 

 the greatest insect pest that the po- 

 tato-grower has to contend with in 

 Pennsylvania. It abounds through- 

 out most of the Northern, Middle, 

 and Western States. Large fields of 

 potatoes can any summer be seen in 

 the Middle States much injured by 

 this minute insect, every leaf appa- 

 rently completely riddled with minute 

 round holes, and the stalks and leaves 

 appearing yellow and seared. Plas- 

 ter frequently and bountifully applied 

 is sure to prevent the attacks of this 

 insect, or to disperse it after it has 

 commenced operations. 



The Colorado Potato-Bug, 



(Doryphora 10 lineata, Say.) This 

 insect, which, according to Dr. Walsh, 

 has in the North- West alone damaged 

 the potato crop to the amount of one 

 million seven hundred and fifty thou- 

 sand dollars, came originally from 

 the Rocky Mountains, where it was 

 found forty-five years ago, feeding 

 on a wild species of potato peculiar 

 to that region, (Solatium rostratum, 

 Dunal.) When civilization marched 

 up the Rocky Mountains, and pota- 

 toes began to be grown in that region, 

 this highly improved pest acquired 

 the habit of feeding upon the culti- 

 vated potato. It went from potato- 

 patch to potato-patch, moving east- 

 ward at the rate of about sixty miles 

 a year, and is now firmly established 

 over all the country extending from 

 Indiana to its old feeding-grounds 

 in the Rocky Mountains. In about 

 twelve years it will have reached the 

 Atlantic coast. 



There is another very closely allied 

 species, known as the Bogus Colorado 



