10 FOURTH ANNUAL REPORT OF 



is rather encouraged, though I believe unintentionally, by Dr. LeBaron in 

 his first Illinois Entomological Eeport/where he gives it as his opinion that 

 the beetle will in time disappear " especially in those localities where it is 

 most abundant, even though we leave the work wholly to Nature." l!foth- 

 ing could, however, be farther from the truth, or less in accordance with 

 past experience. It may, and very generally does, prove more injurious 

 during the first two or three years of its advent than subsequently; because 

 time is required for its natural enemies to multiply sufficiently to keep it in 

 check. But wherever it once obtains a footing, there it may be expected to 

 remain for all time to come — vascillating, it is true, from year to year, in 

 numbers and consequent power to do mischief, according as the conditions 

 for its increase or decrease are favorable ; but always present to take its 

 chances in the great struggle for existence, and to get the upper hand if it 

 can. 



Mr. Thomas Meehan of the Gardeners' Monthly, writes me that while in 

 Colorado the past summer he met with veiy few beetles, and that these 

 seemed to favor the Solarium cormitum; and persons often wonder why the 

 insect does not swarm in the Territory from which it takes its popular name. 

 I have been repeatedly informed by men living on or near the Eocky Moun- 

 tains, and more especially by Mr. J. Savage, of Lawrence, Kans., that at a 

 certain altitude it scarcely ever touches the Potato, but confines itself to the 

 wild cornutum; and it necessarily cannot be as numerous in thinly settled 

 parts of the country as in parts more thickly populated. It received the 

 popular appellation of "Colorado," not because it was numerous there, but 

 because it was first found there by entomologists long before it had advanced 

 to any of the Territories or States to the East. There are hundreds of in- 

 sects that in like manner take their name from some particular district where 

 first discovered, though they often aftei'wards prove to be far more common 

 in other districts. 



New Food ; Cabbage. — It is a notable fact, and a most important one 

 for us, that the Colorado Potato Beetle has in the past been found incapable 

 of flourishing on any other plants but those of the Nightshade Family (So- 

 lanaceoi), and hitherto it has only been known to thrive upon the nightshade 

 genus proper (Solanum) which includes the Egg Plant, the Horse nettle and 

 some other wild species west of the Mississippi, such as rostratum and cornu- 

 tum, which are known by various popular and local names. Upon the 

 Nettle (S. carolinense), which is common with us but is mostly replaced in 

 Kansas by the S. rostratum, it seems to delight even more than upon the 

 Potato, and I have found it quite injurious to other plants of the same genus, 

 such as the warscewiczi, robustum, discolor and sieglinge, which are often cul- 

 tivated for their ornamental foliage. The other common plants of the Fam- 

 ily such as the Tomato {Lycopersicum), Ground-cherry (Physalis), Thorn-ap- 

 ple (Datura), Henbane {Hyoscyamus), Apple of Peru (Mcandra), Tobacco 

 {Nicotiana), Belladonna, Petunia and Cayenne Pepper, are not overmuch to 

 its liking, though upon a pinch, it will feed on all of them, and especially on 

 the first named. The Cayenne Pepper, if eaten to any extent, is actually 

 poisonous to it, as we learn from Dr. LeBaron. 



