339 



Hagan (H. R.). The Codling Moth {Carpocapsa pomonella, L.). — Utah 

 Agric. Coll. Expt. Sta., Logan, Circ. no. 30, March 1918, 4 pp., 

 1 fig. [Received 6th June 1918.] 

 This brief bulletin gives a concise account of the Ufe-history of the 



codling moth {Cydia pomonella), together with directions for its control 



by spraying and banding. 



Hagan (H. R.). The Alfalfa Weevil {Phijtonomus posticus, F.). — 

 Utah Agric. Coll. Expt. Sta., Logan, Circ. no. 31, April 1918, 8 pp., 

 4 figs. [Received 6th June 1918.] 



Hypera variabilis {Phytonomus posticus) (alfalfa weevil) is rapidly 

 increasing its area of distribution, flight being the means by which 

 this occurs. The summer flight takes place late in the season, when 

 the adults seek shelter for hibernation, though a large percentage of 

 them never leave the fields in which they have been feeding. In the 

 spring, the over-wantering adults make their spring flight in search 

 of food, these two migrations causing the weevil to spread at the 

 average rate of 20 miles a year. Along favoured routes, such as 

 roadways, ditchbanks and railways where escaped lucerne is growing, 

 the rate of spread is much more rapid, and may be 50 to 60 miles in 

 a season. 



Damage is caused by the overwintering females ovipositing in the 

 young lucerne stems, as many as 40 eggs being laid in each puncture, 

 while a single female may lay 600 to 800 eggs during the spring. 

 In warm, dry weather the process is completed in a few days ; in a 

 cold, wet season it extends over several weeks. 



The larva, on hatching, seeks the developing leaf-buds, feeding upon 

 the growing tip and stopping the growth. As it grows it feeds upon 

 the larger leaves, with the result that a very hght first crop is obtained, 

 and this cannot mature till the larva has become full-grown and 

 dropped to the ground. Here it spins a cocoon in some shelter such 

 as a dry, curled leaf, but does not burrow into the soil to pupate. 

 The adult emerges after a pupal period of about 10 days. 



Since the greatest loss is due to larv^al attack on the first crop, which 

 also delays the second crop, remedial measures should have for their 

 aim the early maturing of the first crop. To attain this, the soil 

 should be well opened in the spring and the best irrigation methods 

 employed to secure maximum growth. If, as sometimes happens in 

 cases of severe infestations, the first crop has not bloomed by the 

 time that cutting is normally due, it is advisable to let the crop stand 

 till about the middle of June to ensure that practically all the eggs 

 have been laid and then to cut and remove the hay as quickly as 

 possible. The field should then be carefully treated with the spring- 

 tooth harrow, followed by the brush or wire drag, in order to break 

 up the surface of the soil, to stimulate the early growth of the secoiid 

 crop, to tear all green tissue from the lucerne cro^\^as so as to starve 

 the larvae, and to make a fine dust mulch, which, heated by the hot 

 sun, would burn and suffocate the larvae dragged into it from the 

 crowns. For this method to be successful the field must be dry. 

 After allowing it to remain in this condition for 2 or 3 days, it should 

 be thoroughly irrigated, when a rapid growth of lucerne should result. 

 As old fields are unable to resist weevil attack so well as young fields, 

 a crop rotation limited to 4 or 5 years of lucerne is advised. 

 (C485) h2 



