475 



September and 10th October. Adults have been taken on Erodium 

 cicutarium growing in the foothills about 4 miles from the cultivated 

 area. During the winter they seek the hills that are sparsely covered 

 with this plant and are exposed to the sun in the morning and afternoon. 

 The invasion of the cultivated area begins about 24th April and 

 continues to 21st May. No adults were seen in the cultivated area from 

 7tli to 22nd April, but nymphs were found on beets showing symptoms 

 of curly leaf. These probably hatched from eggs deposited by a few 

 adults that hibernated in the cultivated area and died after oviposition. 

 This species does not undergo complete hibernation. Under experi- 

 mental conditions the longest period during which adults survived 

 without food was 29 days. Under field conditions the egg-period 

 varied from 16 to 38 days during September to February. In cages 

 the first nymphs hatched 15th April, and 22 adults were reared 

 between 15th June and 27th June, the nymphal instars covering about 

 30 days. The second brood began to hatch on 10th September, the 

 first adult appearing 21st October. In another experiment 12 adults 

 were reared between 17th June and 4th July from eggs deposited on 

 14th March. The adults of the second brood appeared from 5th to 

 15tli November. In view of the winter migration of the insects from 

 cultivated areas, it is suggested that beet should be planted early if 

 weather conditions render it at all possible. In certain districts 

 E. tenella was found to remain on Australian saltbush all the year. 

 As the seed is distributed by birds, there is danger of this plant 

 spreading to beet fields, in which case even early planted beets may 

 become infested. 



Observations made to determine how curly leaf is transmitted to 

 sugar-beet show that the insects cannot produce the disease unless they 

 have fed on diseased plants. Thus adults feeding on beets in the 

 cultivated area which harbour the disease transmit it to Erodium to 

 which they migrate in the autumn. The nymphs that have already 

 hatched from eggs deposited on this plant thus become virulent, and 

 the adults to which they give rise transmit the disease again to the 

 cultivated area. Lists are given of plants from which E. tenella was 

 collected and those from which it was bred and transmitted curly leaf 

 to sugar-beets. 



Burke (H. E.). U.S. Bur. Entom. Biological Notes on the Flat- 

 headed Apple Tree Borer [Ckrysohothris feinomta, Fab.) and the 

 Pacifle Flatheaded Apple Tree Borer {Chrysohothris mall, Horn). 

 — Jl. Econ. Entom., Concord, N.H., xii, no. 4. August 1919, pp. 

 326-330. 



The Buprestid beetle, Chrysohothris mali, Horn, is much more 

 common in the Pacific States than C.Jemorata, F., and it is believed 

 that a great deal of the damage ascribed to the latter in these States 

 and the Rocky Mountains is really caused by C. mali. Both species do 

 a considerable amount of damage to fruit and shade-trees and resemble 

 each other closely in habits, seasonal history and nature of injury. 

 A list is given of the food-plants recorded for the two species and those 

 from which they have been bred, including a great variety of orchard 

 and forest trees. 



(60i) c2 



