376 THE MONTHLY BULLETIN. 



April or May. In such cases of early defoliation the work is due to the 

 overwintering hoppers. With the appearance of the young the number 

 is. greatly increased and thus the injury becomes still greater. By mid- 

 summer the second brood appears and the numbers are again greatly 

 increased. If each of the females of the overwintering hoppers lays 

 100 eggs and half of this number hatch into females, which in turn lay 

 100 eggs, the progeny from a single individual at the end of the season 

 will amount to 5,000. Thus, for each hopper that comes on to the vine 

 in the spring there will be, if all conditions are favorable, 5,000 hoppers 

 by midsummer. This accounts for the hoppers appearing literally in 

 swarms by midsummer and later. 



It is not until this time that most groAvers are at all concerned 

 about the hopper injury, and it is then too late to do anything very 

 effective. At this time a large portion of the interior of the vine has 

 all the leaves dried and broMai, and many more have fallen off entirely. 

 This injury or complete destruction of the leaves prevents the berry 

 from maturing properly, for it is in the leaves that the sugar and con- 

 sequent sweetness and flavor is manufactured. Injury to the leaves also 

 has its effect on the growth of the vine, the canes fail to ripen normally 

 for the next year's wood, and many of the buds fail to develop in the 

 following spring. In cases of severe hopper injury, therefore, not only 

 is the immediate crop reduced both in quality and quantity, but the vine 

 m.ay be more or less permanently stunted or even killed. 



Life History and Habits. 



If in going through the vineyards at this season one picks up the leaves 

 that may have gathered in bunches by the wind, or disturbs any of the 

 green growth in the vinej^ard or along the bordering roadsides and 

 fences, there will most likely be seen small, pale-colored insects that fly 

 up before' you and soon settle close by again. These are the hoppers as 

 they are found in the winter season. During the warmer and brighter 

 days they will be found activel}^ feeding on a large variety of plants that 

 may be growing within easy range of where they were feeding during 

 the summer. With the cold, wet days, the}^ do little or no feeding, and 

 remain much less active, under leaves or rubbish, or protected by grow- 

 ing plants. At no time in the winter, however, do they feed so 

 voraciously as during the breeding season in the full warmth of summer. 



As the foliage appears on the vine in the spring, these overwintering 

 hoppers leave their more varied winter food plants and attack the vine 

 exclusively. By the time the shoots are four to eight inches long all the 

 hoppers have deserted their winter plants and now remain on the vine 

 until the leaves fall in the autumn. After feeding for three or four 

 weeks on this new growth in the spring, the Overwintering hoppers begin 

 egg laying. The eggs are deposited on the under side of the leaf and 

 within the tissues. They are inserted here by means of a saw-like 

 ovipositor, and covered as they are on all sides, they are beyond the 

 reach of any spray. The number laid is 75 to 100, they hatch in from 

 fifteen to twenty days, and there appears the young hopper, which is a 



