The Colorado Beetle. 



and the edges of the leaves. They are also said to feed on 

 the stalk, so that the whole potato haulm is attacked. 



When mature, the larvae fall to the ground and burrow 

 under the soil and there pupate. In America this stage 

 seems to last a week, for Riley, after stating that the larvae 

 mature in from two to three weeks, says, " the beetle stage is 

 assumed in about a month from the time of hatching." 



How many broods might appear in Great Britain, of course, 

 we do not know. As many as three are observed in North 

 America. In Great Britain there is no reason why three 

 broods should not occur, as the larvae seem to grow very 

 rapidly from observations made on those taken away from 

 Tilbury Docks. 



When the weather commences to become cold in the 

 autumn the beetles bury themselves in the earth, where they 

 shelter during the winter, as well as amongst rough herbage 

 and under rubbish of all kinds. 



The beetles are extremely hardy and can withstand any 

 amount of rough usage. They have been put into chloro- 

 form for two hours, and 40 per cent, solution of formalin for 

 longer, and not affected. In plain water some of the Tilbury 

 specimens were floated for two days and were not in the 

 least injured. The pupae were soaked in sandy soil and 

 paraffin, and after two days they were found to be alive. It is 

 extremely unlikely therefore that such treatment would act 

 out of doors. Both larva and adult can eject a dark fluid, 

 which is thought by some to be poisonous, but which seems 

 quite innocuous. 



Its Food Plants. 

 There is no doubt that when pressed for food this beetle 

 will take to a great number of plants besides the potato. In 

 its native home it mainly feeds, under natural conditions, on 

 the two wild Solanums, S. rostratum and S. cornutum. The 

 Solanace<B) or nightshade and potato family, form its staple 

 diet, especially the true Solanums. The Solanums upon which 

 the larvae have been found in America, are the following : The 

 common horse-nettle (S. Carolinense), found in Missouri 

 and east of the Mississippi ; 5. robustum, S. discolor , S. Sieg- 

 lingii) and S. Warscewiczii. 



