June, '22] Strickland: poisoned molasses for noctuids 217 



of a fence post, and the free end of the wick is nailed to the post through 

 a piece of absorbent cloth. When a rapidly killing poison is used, and 

 it is desired that material obtained be preserved, a partial funnel of 

 mosquito netting or paper can be attached to the post as is shown in 

 figure 6,1. A modification, suggested by Mr. Carter, is to replace the 

 cloth with a shallow pan made from a tomato can (Figure 6, 2). This 

 forms a reservoir for any surplus flow of poison. 



The bottle is fastened to the west side of the fence post in order 

 that it will not be exposed to the direct rays of the sun till the afternoon. 

 The heat then causes its contents to expand and to drive some of the 

 liquid down the wick and on to the cloth. This action usually continues 

 till nearly sunset and it liberates sufficient bait to attract moths through- 

 out the night. After the sun has set a reverse pressure in the bottle 

 draws in sufficient air to replace the expelled liquid. 



Provided the variations in temperature are not too extreme, or fer- 

 mentation too rapid, a quart bottle will run every evening for from 

 ten to fourteen days. We have tried several modifications of reservoir 

 and methods of controlling the flow of bait, such as the "drinking- 

 fountain", siphon, and gravity feed, but find the inverted bottle to be 

 as satisfactory as any. 



Having obtained a satisfactory apparatus, our next concern was to 

 find a suitable poisoned bait. As a basis a 10% solution of cane molasses 

 was used in all cases. This ferments within a few days of mixing. 

 In the fall of 1920, experiments were made in which the decantation 

 from a saturated solution of white arsenic was used as the diluent. 

 This killed moths in the laboratory in from S to 40 hours, but was found 

 to be som.ewhat deterent to feeding. 



When this solution was used in bottle traps moths fed on it and 

 obtained sufficient poison to cause their death within 24 hours. This 

 was proved by captrued specimens. In the field, however, they all 

 flew from the traps before dying. It was hoped that some immediate 

 killer could be obtained in order that we might estimate the value of 

 the traps, and be certain that gravid females were unable to deposit 

 their eggs before dying. It was also highly desirable that those who 

 might be using the traps as a practical means of control should be able 

 to see some results from their efforts in the form of dead moths. 



To this end we planned a series of experiments in 1921, but it was not 

 until nearly the end of the season that Mr. Seanaans found quassia to be 

 the nearest approach to what we desired. Subsequent observations 

 showed that this material must be used in conjunction with some other 

 poison. 



