364 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 15 



plant ! It was not uncommon to find a dozen or more beetles, while the 

 average in the parts of the field suffering damage was about 6 beetles to 

 a plant. 



Of the two species concerned in this infestation, Blapstimis coronaden- 

 sis and B. dilatatus, the former was by far commoner. 



A niunber of experiments were made with different materials which 

 were placed on the ground around the stem of the plant. Among the 

 materials used were ground tobacco, nicotine dust, nicotine dust and 

 calcium arsenate, Bordeaux mixture (both wet and dry), Bordeaux mix- 

 ture with nicotine dust, and hydrated lime. Some were merely applied 

 to the top of the ground, while others were covered with soil after appli- 

 cation. Later examinations showed that the wet sprays were valueless, 

 but that dry dusty material had a decided deterrent effect. This was 

 checked up by using hydrated lime on a larger scale, with results as 

 follows : 



Check I 33 plants with beetles around stem; 2 plants with no 

 Undusted \ beetles. 



16 plants with beetles around stem; 29 plants with no 

 beetles (5 of these plants did not have lime thoroughly 

 about stem) 

 Check \ 23 plants with beetles around stem; 13 plants with no 

 Undusted) beetles. 



Field observations confirmed these results. If the lime were so 

 applied as to cover the ground completely around the stem, the beetles 

 ceased to feed. 



For applying the lime, a bellows type of hand duster was used. 

 With the feed wide open, a single ptiff of dust thoroughly covered the 

 ground on one side of the stem. The operator proceeded up the row, 

 giving a puff to each plant, and then came back on the same row, so 

 as to cover the ground on the opposite side. 



Very little feeding was observed after the lime was applied. A 

 number of plants died, having been previously injured, so that the 

 increased weight of the growing top caused them to break off. 



The pepper fields were under irrigation, and the one most seriously 

 damaged was level with a gentle slope to the South. To test the possi- 

 bility of killing the beetles by flooding the field, a number were brought 

 to the laboratory and placed on soil submerged in water. The beetles 

 were very active for over an hour, when some became quiescent. These 



