NO. 10 TROPISMS OF LEPIDOPTERA — McINDOO I7 



mation as to the time of appearance of the moths. Other similar 

 reports on this subject are by Headlee (30) and by List and 

 Yetter (41). According to Fowler (22), baits are also being- used 

 in South Australia as an aid in codling-moth control. This writer 

 says that large numbers of moths can be caught in suitable traps 

 properly baited, and that it is profitable to put out a number of 

 traps from the last week in October until the end of November, and 

 again from the end of January to the middle of February, which 

 intervals cover the periods of maximum emergence and give the best 

 results. Baits are likewise being used in South Africa. 



After experimenting with a large number of aromatic substances 

 for several years at Clarksville, Tenn., Morgan and Lyon (67) have 

 recently reported that amyl salicylate incites a decided feeding response 

 in tobacco hornworm moths (PlilcgctJwntitis Carolina), inducing an 

 attraction to artificial flowers. Sixteen species of Sphingidae were 

 caught in traps baited with the chemical besides the two species 

 frequenting tobacco. In field experiments a number of female moths 

 sufficient to have deposited 8.1 eggs per tobacco plant were caught in 

 traps. Amyl benzoate was also found very attractive. 



Attractants and repellents have been used in control measures 

 against other species of moths, and a further discussion is perhaps 

 not necessary to convince the reader that this new line of research 

 merits further serious consideration. 



2. CHEMOTACTIC EXPERIMENTS ON CODLING-MOTH LARVAE 



The preliminary results which follow were obtained by testing 

 codling-moth larvae with attractants and repellents. As an example 

 of the procedure in the tests, a recently hatched larva was put in the 

 phototactic box described on page 12 to be sure that it responded 

 normally to light. After tracing its tracks (fig. 2, A, a) a sheet of 

 white paper was laid on the table by the south window. Twelve cubes 

 of green apple, each 4 or 5 millimeters in size, were placed an inch or 

 more apart on the paper inside a circle having a diameter of 5 inches 

 (fig. 2, A). The larva was then placed inside the circle and allowed to 

 search for the pieces of apple while slowly moving toward the light. 

 It was given 10 chances and each time it touched a piece of apple or 

 the circle that particular chance ended. Pieces of cork of the same 

 size as those of the apple and squares equally large, drawn with a 

 pencil inside the circle, were used as controls. 



Several larvae recently hatched went to the pieces of apple, on an 

 average, in 65 per cent of the chances ofifered to them ; several larvae 



