i9io.] 



The Colorado Beetle. 



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is required by Order of the Board, it should be borne in 

 mind that a pig suffering from that disease may also be 

 affected with swine fever, and that the Swine Fever Order of 

 1908 requires that every person having in his possession or 

 under his charge a pig affected with, or suspected of swine 

 fever, shall give notice to the police. In this connection 

 attention is called to the " Notice to Pig Owners " issued by 

 the Board. 



THE COLORADO BEETLE. 



This beetle (Leptinotarsa (Doryphora) decemlineata, Say.), 

 a member of the family Chrysomelidce, was first known in 

 the west of the United States, and has now spread over the 

 United States and Canada. In its native home in Colorado 

 it was known to feed on wild plants of the natural order 

 Solanacece, but about 1850, having found its way to the cul- 

 tivated plants of settlers in the West, it began to travel east- 

 wards. By 1859 it had reached Nebraska, and by 1865 it 

 had crossed the Mississippi. It had passed north into 

 Ontario by 1870, and in 1874 it had reached the Atlantic. 

 Later it obtained a partial footing in England and the Con- 

 tinent of Europe, but prompt preventive and remedial 

 measures removed the danger. 



Food Plants. — Solanaceous plants, chiefly those of the 

 genus Solanum, are the favourite food plants of the Colorado 

 Beetle. Solanum rostratum and Solanum cornutum are the 

 two wild species upon which the beetle was first noticed feed- 

 ing. In preference to these and to other wild species of 

 Solanum, the beetle chooses the cultivated potato. The tomato 

 (Lycopersicum) is also attacked. The following other Solan- 

 aceous plants have been used as food plants: — Thorn-apple 

 (Datura), henbane (Hyoscyamus), tobacco (Nicotiana), apple 

 of Peru (Nicandra), winter cherry (Physalis), belladonna 

 (Atropa), and Petunia. 



Plants outside the order Solanacece on which the insects 

 have been found feeding are : — Various poppies, especially 

 the Mexican or prickly poppy (Argemone Mexicana), pigweed 

 (Amaranthus retro flexus), hedge mustard (Sisymbrium 

 officinale), oats, smart-weed (Polygonum Hydropiper), red 



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