90 Habits of the Tomato Moth 



the succeeding days. If these numbers are traced down the columns 

 and compared day by day it will be seen that there is a considerable 

 advantage in using the substance at a greater strength than 3 lbs. to 

 100 gallons, while between 5 and 10 lbs. there is probably no more 

 variation than could be accounted for by experimental error. However 

 as the plants were considerably damaged by the feeding when the weaker 

 concentrations were used, and at strengths of 6 and 10 lbs. only traces 

 of feeding were seen, it is recommended that a concentration of 6 lbs. 

 of the paste in 100 gallons should be employed. There is no advantage 

 in using it at a greater strength. 



A knapsack sprayer is quite efficient if saponin is used, and it was 

 found that a man using one of these machines could easily keep pace 

 with the planting over 25 acres of plants. The spray should fall down- 

 wards onto the foliage, and the operator should wear a piece of muslin 

 over the face to prevent the poison getting into the eyes and nose. The 

 plants should not be watered until the following day when the spray is 

 thoroughly dry. 



If larvae are seen feeding in the propagating houses the plants should 

 be sprayed at once. In the houses known to be infested they should 

 always be sprayed shortly after planting out. Another spraying should 

 be carried out about a month before fruit picking will commence. This 

 is the most important application and should be done in every block 

 in the nursery where there has been any caterpillar in the previous year. 

 It is a mistake to delay this final spraying because no larvae are seen 

 feeding, as the arsenate cannot be employed on older plants without 

 prejudice to the industry, and they may appear for the first time after 

 it is too late. The grower will then be left with no remedy except picking 

 off the insects by hand. This spray not only kills the larvae present 

 when it is applied, but also all that subsequently feed on foliage that 

 has been efficiently treated. 



As some of the growers have been reluctant to adopt spraying, it 

 seemed desirable to obtain practical proofs of this method of control 

 over hand-picking. Reference was made above to a 200-foot house 

 (one-tenth of an acre) which was isolated from the rest of the block by 

 a stretch of hessian dropped from the gutter to prevent the passage of 

 moths. The 1600 plants were untreated while those in the remainder of 

 the block were sprayed twice with arsenate of lead. Each of the un- 

 sprayed plants was examined twice weekly and all larvae found were 

 counted and destroyed. From four to six hours a week were devoted 

 to this work — almost the equivalent of the entire time of one man over 



