proceedings: entomological society of WASHINGTON 1 49 



McMahon, of the Entomological Laboratory at Annapolis Royal, 

 Nova Scotia. 



The regular program was as follows: 



W. M. Mann: Notes on the Solomon Islands. An account of a col- 

 lecting trip to these islands, illustrated by lantern slides showing the 

 topography, flora, fauna, and the various types of natives, their dress, 

 habits, implements, and customs. 



N. E. McIndoo: The olfactory sense of lepidopterous larvae. The 

 author described experiments conducted to determine if the larvae 

 are able to distinguish between various plants offered them as food, 

 the result of these experiments proving that they are able to do so. 

 The author is of the opinion that this is accomphshed by means of an 

 olfactory sense and locates the seat of this sense in certain minute 

 pits scattered over various portions of the body, each pit connected 

 with a sense cell. The structure and position of these organs were 

 illustrated by charts and drawings. 



In discussing this paper Mr. Busck congratulated Dr. McIndoo 

 on his work and commented on the far-reaching possibilities it sug- 

 gested in economic entomology, when we shall know enough about 

 these supposed olfactory organs to tempt the codling moth away 

 from the apple by a perfumed bait. He pointed out that the organs 

 described by Dr. McIndoo were by no means a new discovery, but 

 that at least those of the head were well known by lepidopterists and 

 had all been carefully mapped out and named in connection with the 

 parts of the head and the head setae. Their position relative to the 

 setae is constant for each species and yields excellent generic and 

 family characters, which enable determination merely from a larval 

 head capsule. 



Mr. Busck stated that he had hitherto considered the punctures as 

 remnants of aborted setae and he still thought they must be consid- 

 ered such, modified to serve other senses than touch; the setae are 

 sense-touch organs and have nerves running to their bases like the 

 punctures. As one ground for this view he mentioned that certain 

 of these supposed olfactory punctures, the ultra posterior punctures on 

 the head, in some species bear a small hair and in others not. 



Mr. Busck criticized and objected to Dr. Mclndoo's arbitrary num- 

 bering of these punctures, starting on the thorax, continuing to the 

 last abdominal segment, and ending with the head. He suggested 

 as more rational and simpler to name them after the part of the body 

 they are found on, and he thought it common sense to adopt the al- 

 ready existing names for the head punctures, which were used by 

 Heinrich and himself and which were named after the head parts on 

 which the punctures are situated. 



Dr. Pierce emphasized the bearing that papers like that under dis- 

 cussion have on taxonomy and economic entomolog\^ and predicted 

 that in future the determination of larvae by the minute characters 

 of small fragments will be very generally possible. 



