2l6 INSECTS INJURIOUS TO VEGETABLES 



tennial year the Colorado potato beetle occupied an area com- 

 posing more than a third of the United States. 



Beetles and larvae are destructive in nearly equal proportion. 

 In its early occurrence as a pest it not only caused entire 

 losses of crops, but sometimes destroyed the potato yield of 

 whole counties, and large portions of some States. Indeed, 

 at one time it materially affected the market price of potatoes 

 by direct depredations and in discouraging farmers in the 

 cultivation of this crop. At the present time growers recognize 

 the fact that the control of the potato beetle is a part of the 

 routine of the culture of this tuber, and that its natural enemies 

 assist in a remarkable degree in reducing its numbers. The 

 insect is nearly always found on its wild plants wherever they 

 Occur and it practically feeds on all solanaceous crops and 

 weeds, including tomato, tobacco, ground cherry, thorn apple, 

 and Jamestown weed, henbane (hyoscyamus), belladonna, 

 petunia, and Cayenne pepper. The tender leaved varieties of 

 potato are most affected, while those with less tender foliage, 

 of the "Peach Blow" and "Early Rose" type, are comparatively 

 immune. 



The beetle hibernates under ground and is credited with 

 being double-brooded with sometimes a third partial generation, 

 which hibernates in the pupal condition. The beetles appear 

 early in spring, issuing soon after the first thawing of the 

 ground, at this season flying during the more heated portions 

 of warm days, making aerial journeys of considerable extent. 

 Larvae hatch in from less than a week to a little later, accord- 

 ing to the prevailing temperature, and in two or three weeks 

 usually acquire maturity, when they undergo transformation to 

 pupae and subsequently to beetles in cells which the larvae 

 form in the earth. The insect is to be found in practically 

 all stages during the summer months, and as long as there are 

 suitable plants for food. A single female is capable of pro- 

 ducing from five hundred to a thousand eggs. The entire life 



