72 



would be killed. Professor Beckwith's notes state (May 11, 1890) that 

 these were exterminated by a fungous disease, and the clover was not 

 seriously injured. Upon looking over the station collection I found 

 specimens of JSf. destructor which unfortunately were without any label, 

 but were among material which was unquestionably collected prior to 

 1896. Upon corresponding with Professor Beckwith he informed me 

 that he distinctly remembered preserving specimens of the aphis in 

 question. As his accession catalogue shows no such specimens to have 

 been numbered, though by no means conclusive, the evidence is at 

 least strongl}^ circumstantial that Nectaropliora destructor occurred in 

 injurious numbers on crimson clover as early as 1890. 



As regards remedies, I have practicall}^ nothing new to offer. It 

 evidently is important to plant crimson clover as far from peas as pos- 

 sible, and to turn it under as early as practicable. 



Brushing, followed by harrowing, was not practiced by our growers, 

 as frequent rains made the soil too damp to make it efficient. Brush- 

 ing into pans drawn between the rows did not commend itself to the 

 growers, though it seems to me entirely practicable and I hope to see 

 the method in use next year. 



While the lice were still confined to the terminals of the late peas, 

 it seemed probable that most of them could be killed by a spray. An 

 attachment fitted from one-half inch gas pipe was readily and cheaply 

 constructed so that five rows of peas could be sprayed at once. This was 

 used with a kero-water pump and Vermorel nozzles, and gave a good 

 spray, which covered the plants very thoroughly. Fifteen per cent 

 kero water was found to evaporate so rapidly in the hot sun that it 

 failed to be effective. Twenty-five per cent killed the lice and reached 

 a large majority of them, but I feared it would injure the vines. 

 Though they were well saturated and looked rather sick for a day or 

 two, however, they were not permanently injured or affected. With 

 15 per cent kerosene an acre was sprayed twice with 5 gallons of kero- 

 sene and 2 barrels of water. One spraying with 25 per cent was much 

 more effective and would be no more expensive. This treatment com- 

 mended itself to me as cheap, practicable, and effective for use while 

 the lice are stil] confined to the terminals and while the vines are still 

 upright, at which time, if at all, the lice must be combated if injury to 

 the crop is to be prevented. I fear, however, that the profit in pea 

 culture to the average grower is too small for him to. ever engage in 

 spraying, though the more successful growers could well afford it. 



Could the fungous disease be grown in the la])oratory and started in 

 the fields early in the season it might prove of value, but so far our 

 pathologist. Prof. F. D. Chester, has been unable to secure its growth 

 upon any culture tried. 



