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beetle," which is much more appropriate than the "Colorado potato- 

 beetle," which is now so generally applied, although no more applica- 

 ble than Nebraska or Iowa Potato-beetle. 



I will give here only descriptions of it in. the various stages of its 

 life and a short summary of the remedies proposed, referring the reader 

 to "General Remarks" at the end of the report for a more extended 

 history of its career in the United States, and of the remedies pro- 

 posed. 



It is broadly oval in form and very convex, giving it an almost hem 

 ispherical shape ; the length varies from three-fifths to three-fourths of 

 an inch, the width across the widest part from one-fifth to a little over 

 one-fourth of an inch ; the thorax is somewhat broader than it is long ; 

 antennae slightly enlarged toward the tip. The general color varies 

 from a pale lemon to an orange yellow ; the head has a round, black 

 spot in the middle ; the thorax is marked with several black dots and 

 short stripes, the two middle ones being the largest ; each wing-case is 

 marked with five very distinct longitudinal black stripesor lines, mak- 

 ing ten on the two, hence the name 10-lineata or 10-lined. 



The only species with which this is likely to be confounded is 

 Doryphor a juncta, which, in the beetle state, is so very similar in ap- 

 pearance that they were for a long time supposed by entomologists to 

 be one and the same species. In juncta the two inner stripes on each 

 wing-case are united at the tip, while in the 10-lineata these are sepa- 

 rate, and the second and third counting from the middle are united at 

 the tip. The leg of juncta has a black spot on the thigh, which is want- 

 ing in 10-lineata. 



The larvae of the two species are'also much alike in form, but show 

 more distinct differences than the beetles. That of the Colorado 

 potato-beetle at first is almost black, but shortly becomes lighter, 

 changing toward a yellow ; in about two weeks it reaches maturity. . 

 At this period it is of a yellowish color, varying in intensity in differ- 

 ent individuals from pale yellow to a deep orange color ; the head and 

 legs are black, and the hind part of the first segment behind the head 

 is also black, while the other part of this segment is yellow ; there are 

 two rows of black spots along each side of the body. It is thick, fleshy, 

 much enlarged, and strongly arched behind the middle ; has six true 

 legs situated on the first three segments, and uses the tip of the last 

 segment as a kind of pro-leg in progression. Length about half an 

 inch. 



The full grown larva of juncta is similar in form, size and general 

 appearance, but differs as follows : the head is pale, the first segment 

 is reddish-brown, edged all around with black ; and there is but one 

 row of black dots along in each side. When young the color is some- 

 what different, the head being brown, and two rows of dots along the 

 sides. 



These differences, combined with the habits of the two species, will 

 enable any one to distinguish the genuine from the bogus potato 

 beetle. 



The true potato-beetle {10-lineata) is otherwise readily distin- 

 guished by its love for the potato plant, which so far the other has 

 not manifested, preferring its rough homely diet— the horse nettle. 



e— 11 



