THE BE AX LADYBIRD. 23 



with the larvae, and the two broods of larvae overlap. Damage was 

 generally worst near fences, along ditch banks, and on beans receiving 

 an extra amount of water by accident or seepage. 



There is a large area in northeastern Colorado devoted to farming 

 and stock raising. This area is known as the Greeley District. 

 Beans of all varieties are grown quite extensively. Several thousand 

 acres are planted to beans every year. A conservative estimate of 

 the damage done to the whole bean crop in that district during the 

 season of 1919 by the bean ladybird is about 5 per cent. This esti- 

 mate at first may seem rather small, but the majority of fields were 

 infested lightly or not at all. In the second place a few fields were 

 more heavily infested than the adjacent or neighboring fields. In 

 those fields coming under our observation the damage by Epilachna 

 eorrwpta varied from an estimated 25 per cent to 65 per cent. One 

 field in particular, of about 15 acres, was damaged at least 65 per 

 cent if not 75 or 80 per cent. Xo remedial measures were applied 

 in this case. 



CONTROL. 



In some of the small truck patches the attack of the bean ladybird 

 was controlled by hand picking. In view of the distribution of the 

 damage, as stated, clean farming or destruction of winter quarters 

 is suggested as an important measure of control. 



As to remedial measures, all rjossibilities were not worked out. 

 On July 10 when the first larva; were observed, the following sprays 

 were tested on large plots in a 9-acre field. Right-angle mist-produc- 

 ing nozzles were used. Approximately 80 per cent of the leaves were 

 covered on one side or the other, the remainder varying from a small 

 amount to none at all. The foliage was heavy. 



Experiment No. 1.- — Lead arsenate, powder, was used at the rate 

 of 2 pounds to 50 gallons of water, with 2 pounds of hydrated lime 

 added. Very little if any damage was noted from the spray. A 

 few dead larvae were found. 



Experiment No. 2. — Lead arsenate, paste, was used at the rate of 

 2£ pounds to 50 gallons of water. Xo damage to the plants was 

 noted. 



Experiment Xo. 3. — Zinc arsenite, paste, was applied at the rate 

 of 2 pounds to 50 gallons of water. This strength caused no dam- 

 age to the plants. 



Experiment No. 4. — Bordeaux mixture, alone, formula 8-6-50, 

 was applied to a plot. Xo damage was done to the plants. This 

 application seemed to be as effective as any of the foregoing during 

 the earlier part of the season, but this plot showed a greater maxi- 

 mum damage after August 1 than did any of the others. The re- 

 mainder of the field and a second field of 21 acres were sprayed with 



