THE LEGUME POD MOTH. 



95 



pods in his experimental plats at Pullman, Wash. On examining 

 some of these larvse it was found that they resembled those of Etiella 

 zincJcenella schisticolor that had been found in lupine-seed pods the 

 previous year, differing only in being larger, measuring about 17 mm. 

 in length, while those from lupine measured only 13 mm., due, with- 

 out doubt, to the difference in food plant. 



The following day a number of the larvae were collected from the 

 field-pea pods and placed on earth in a flowerpot, into which they 

 immediately burrowed. 



From a larva placed in a pill box an adult emerged on August 27 and 

 on the same day two moths emerged from the earth in the flowerpot. 



EXPERIMENTAL WORK CARRIED ON DURING THE SEASON OF 1910. 



In the spring of 1910 the Bureau of Plant Industry planted over 

 100 varieties of field peas at Pullman, Wash. These were planted 



Fig. 33. — The work of the legume pod moth (upper row) compared with that of the pea 

 weevils (Bruchidse) (lower row). Enlarged. (Original.) 



in plats 1 rod square, in order to study development and adapta- 

 bility of the various varieties under semiarid conditions. Mr. M. W. 

 Evans has very kindly permitted the use of his field notes, and of 

 the crop when harvested from these plats,, which has greatly facili- 

 tated this investigation. These notes indicated the time of planting, 

 the time the first flowers of each variety came into bloom, the time 

 of maximum blooming, and the time of last blossoms. The seed 

 harvested from each plat was kept in individual packages. 



By actual count the writer determined the percentage of damage to 

 each variety of field peas by these moths. The "worms" do not 

 usually consume the entire seed, but so far destroy it as to render ger- 

 mination impossible. Seed thus damaged is easily distinguished from 

 that attacked by Bruchus. The latter makes a very smooth round 

 exit hole, while the former gnaws into the seed very irregularlv. 

 (See fig. 33.) 



