44 



THE AMERICAN ENTOMOLOGIST. 



the specimens, that the supposed true Colorado 

 Potato-hugs simply helonged to the bogus 

 species. Hence it is but reasonable to infer that 

 in other cases, where it was not practicable to 

 examine the specimens, the same yery natural 

 error had been inadvertently committed. 



Habits of tlic Colorado Potato-bng. 



The Colorado Potato-bug, though it has ac- 

 quired a prescriptive title to the appellation of 

 "bug," is uot, entomologically spealdng, a Bug 

 (order IIete7vptera), but a Beetle (order Cole- 

 optera) . It might perhaps be desirable, if it 

 were possible, to get people to call it a " Potato- 

 beetle;" but as loug as we all of us continue to 

 talk every day of "shipping" goods by a rail- 

 road car, as well as by a ship, and as long 

 as everybody, including the Almanac-makers, 

 writes about "sunrise" and "sunset," while 

 in reality it is the earth, and uot the sun, that 

 rises and sets every day, we must be content to 

 smother our partiality for entomological purism, 

 and talk with the vulgar though we think with 

 the wise. 



The wings of this insect, like those of sev- 

 eral allied species, are of a bright rose-color, 

 and with its cream-colored body, and the five 

 black stripes' upon each wing-case, it presents a 

 beautiful appearance as it flies abroad in the 

 clear light of the sun. The junior editor of this 

 l^aper was the first person in the United States 

 to breed tliis species from the egg to the beetle 

 state, and to ascertain that it required less than 

 a month to pass through all its changes. In the 

 Prairie Farmer for August 8, 1S63, will be 

 found the full account, by this wi-iter, of the 

 whole process, illustrated by a figure of the 

 larva. Subsequently, in 1866, Dr. Shimer added 

 some very interesting particulars bearing upon 

 this subject, in a paper wliich he published in 

 the Practical Entomologist (Vol. I, pp. 84-5). 

 There are about three broods of larvas every 

 year in North Illinois and Central Missouri, each 

 of which goes underground to pass into the pupa 

 state, the two first broods coming out of the 

 ground in the beetle state about ten or twelve 

 days afterwards, while the last one stays under- 

 ground all winter, and only emerges in the beetle 

 state in the following spring, just in time to lay 

 its eggs upon the young potato leaves. The eggs, 

 it may be added, are of a yellow color, and are 

 always laid upon the under side of the leaves in 

 patches of 20 or 30. At Fig. 33 a a the eggs are 

 sliown, and at Fig. 34 d d those of the Bogus 

 Colorado Potato-bug, which are of a liglilcr 

 color, are also shown, all ot (he natural size. 



Unlike many other noxious insects, this larva 

 is not a general feeder, but is couflned to plants 

 belonging to the potato family (Solanaceoi) , 

 and especially to the genus to which the potato 

 belongs (Solanum). Occasionally it feeds on 

 the tomato, and a few specimens have been 

 noticed by us on the ground-cherry (Physalis), 

 and on the imported Jamestown-weed, or gymp- 

 son-weed {Datura) . According to Mr. Terry, 

 of Iowa, it also occurred in that State, several 

 years ago, on the horse-nettle {Solaniim), upon 

 wliich plant we have ourselves noticed it in 

 great numbers in Missouri ; and it is certainly 

 far more destructive to the egg-plant than even 

 to tlje potato. Now, the egg-jilant, the horse- 

 nettle, and the potato, all three of them belong- 

 to the same genus {Solanum), as tlie wild plant 

 upon which the larva originally fed in the Rocky 

 Mountain region; but the egg-plant and the 

 horse-nettle are botanically more closely related 

 to the last than is the potato ; being, like the 

 Rocky Mountain potato, covered with thorny 

 prickles, wliile the cultivated potato is perfectly 

 smooth. On the other hand, the cultivated po- 

 tato is much more nearly related to the Rocky 

 Mountain species thau is the tomato; which last 

 has, by modern botanists, been removed from 

 the genus to which the other two appertain, and 

 placed in a genus by itself. It would seem, 

 therefore, that the closer a plant comes to the 

 natural food-plant of the insect, the better the 

 insect likes it. 



It is undoubtedly a most singular and note- 

 worthy fact that, out of two such very closely 

 allied species as the bogus and the true Col- 

 orado Potato-bugs, feeding respectively in 

 in the first instance upon very closely allied 

 species of wild potato (Solanum rostratiom und 

 S. carolinense') , the former should have perti- 

 naciously refused, for about half a century, to 

 acquire a taste for the cultivated potato, with 

 whicli it was all the time in the closest and most 

 immediate contact, while the latter acquired that 

 taste as soon as ever it was brought into contact 

 with that plant. But, after all, tliis is not so 

 anomalous and inexplicable as the fact that the 

 Apple-maggot Fly (Trypeta pomonella,AYals\\) , 

 wliich exists both in Illinois, New York, and 

 New England, and the larva of which feeds in 

 Illinois upon the native haws, and has never 

 once been noticed to attack the imported apple 

 there, should, within the last few years, have 

 suddenly fallen upon the apple, both in New 

 York and New England, and in many localities 

 there, liave become a more grievous foe to that 

 fruit (Imu even (lie imported Apple-worm 



