35 



Vacant spaces could be seen extending sometimes 10 or 15 feet down 

 a row and covering an area from 2 to 5 rows wide. Those few 

 injured beets that had survived the attack were dry, ahnost lifeless., 

 the leaves being small and the root of no value. 



Upon reaching the Santa Ana Valley and neighboring beet regions 

 in southern California, especially at Chino, the work of this insect 

 became more common and the damage in places was quite severe. 

 The owners attributed the loss to plant lice and cut worms, but a very 

 slight examination was sufficient to show that the beets had been 

 attacked by some borer, and that work on them was still in progress. 

 At Huntington Beach, near Los Angeles, and at Chino, the larvae 

 causing the injury were found in several fields, and at the latter 

 place moths, which later proved to be the adult form of this phycitid 

 borer, were rather common in one field on the beet-sugar company's 

 ground. 



From examination of the beets it is evident that the young larva 

 at first works on the beet just be- 

 low the bases of the leaves, eating 

 through the outer skin and either 

 boring directly into the beet or 

 working its way around the crown 

 beneath the epidermis, thus making 

 a swollen line that has the appear- 

 ance of a mine, often much like 

 early work of Pegomya incina and 

 similar sj^ecies mining in leaves. 

 As the larva grows in size it forces 

 its Avay farther and farther into the 

 beet until it reaches the center, when 

 it may bore directly downward or pass on tlirough the beet and 

 then return and feed up and down inside the root. In all the gal- 

 leries examined I found more or less evidence of a silken tube. 

 Those of the older larvte that were feeding on the outside of the 

 beet had constructed tubes covering their operations and protecting 

 them from contact with the soil. Sometimes these tubes extended 

 for a considerable distance away from the beet. These tubes are 

 very fragile, and not nearly so firm in construction as those made 

 for hibernating purposes by the sugar-beet webworm {Loxostege 

 sticticalis) . 



Several larvae were usually found attacking a single beet, and, from 

 the fact that tubes were found extending from beet to beet down the 

 rows, it is probable that the larvae after killing one beet may pass on 

 to another one in which they will complete their gro^^th. Pupae 



Fig. 



9.—Hulstea undulatella: adult and 

 larva — enlarged (original). 



