THE GREEN JUKE BEETLE. 23 



(see Pis. V and VI). Many fibrous roots are broken either by the 

 movement of the larvae traveling from one place to another below the 

 surface or by their feeding when desirable food is near the roots. 

 Certain methods of farming or trucking, particularly those deemed 

 necessary in growing such crops as parsley, lettuce, celery, beets, and 

 turnips, where the seed is sown in drills, afford ample opportunity 

 for the young seedling plants to be injured as stated. Later, in such 

 crops as parsley, for instance, where the plants are grown in close 

 rows, the roots act as a barrier to the movement of the larvae ; hence 

 they are much injured, and the outer leaves of the plants turn yellow, 

 giving additional indication that root injury has taken place. Fur- 

 thermore, the habit of the larvae of coming to the surface at night, 

 or of working close to the surface of the soil during cloudy days, is 

 responsible for the undermining and uprooting of many larger plants. 

 The carriage of soil into the heart of the susceptible crops mentioned 

 also causes the plants to become choked, and is likely to produce rot. 

 In many instances rows of plants have been found thus injured, let- 

 tuce being the greatest sufferer in this respect. 



The object of the larvae in coming to the surface at night probably 

 is to change their feeding areas. Hundreds of larvae may be observed 

 traveling promiscuously, and the fact that the light of a lantern 

 causes them to become stationary, or immediately to bury themselves 

 beneath the surface, has prevented the determination as to whether 

 or not they feed on the surface. 



Where the larvae occur abundantly the continual stirring up of the 

 soil renders it unfit for the growth of crops of any kind. Innumer- 

 able tracks are made by the larvae while crawling on their backs, and 

 as they crawl over plants leaves are buried, or soil carried into the 

 hearts of growing plants. 



Number of Molts. 



During the growing period the larva molts twice, a third molt 

 occurring when the larva transforms to pupa. 



A large series of larvae were successfully carried through the 

 molting stages in tidewater Virginia, and it was determined that 

 the vigor of the larva when hatched, the richness of the food during 

 its active existence, and the frequent changing of the soil all played 

 an important role in determining the period before the larva molts. 

 In other words, when all conditions are favorable for rapid growth, 

 including warmth and the necessary moisture, the time between 

 molts is comparatively short. From the time the larva is hatched 

 until the first molt the minimum period observed was 13 days and 

 the maximum was 27. From 38 larvae carried through the molting 

 stages the average number of days before the first molt occurs was 

 determined to be 18. The minimum and maximum number of days 



