176 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 10 



on dorsum and laterad. The plates each bear spinules. Head and 

 legs brown. The other species under consideration is a Geometrid, 

 two small specimens being taken. They are grayish brown in color 

 and practically nude of hairs. Specimens of the latter two species 

 were submitted to Mr. August Busck of the U. S. National Museum 

 for determination. All these larvae were taken in tanglefoot in situa- 

 tions distant from the posts, where they could not possibly have 

 crawled. The screens on which the latter, or practically hairless, 

 larvse were taken were located quite near tree growth — 200 to 500 feet. 

 The recording of three and possibly four species of lepidopterous lar- 

 vae other than the gipsy moth {Porthetria dispar L.) and the nun moth 

 (Psilura monacha) being carried by the wind adds to the probability 

 that there are many other species dispersed in this way. 



Summary ■ 



Additional data have been collected on long distance wind disper- 

 sion of gipsy moth larvae; namely, across Cape Cod Bay off the coast 

 of Massachusetts. The direction of the wind recorded at the time 

 taken and previously, indicated the source of infestation to be 19 to 30 

 miles distant on the mainland. Frequent examinations of the screens 

 and close data kept on movements and direction of the winds were 

 necessary to make these records of value. 



Screens used in the cranberry bog experiments and placed horizon- 

 tally over the vines were well adapted to catch the drop of small larvae 

 floating over such areas while the upright wire and cloth screens 

 proved better for securing long distance spread. 



The recording of three extra lepidopterous species and possibly a 

 fourth being carried by the wind in the larval stage suggests some 

 possibilities for investigation with others along this line. 



President C. Gordon Hewitt: The paper is now open for dis- 

 cussion. 



Mr. a. F. Burgess: Some may wonder why the Geometrid and 



Plate 10 

 Fig. 1. Thermometer, weather vane and anemometer used in recording weather 

 data in connection with Dispersion Experiments. Fig. 2. Wire screen at Province- 

 town, Mass., upon which small gipsy moth larvae were taken, having been wind- 

 borne about twenty-five miles. Fig. 3. Upright cloth screen; a type used in Disper- 

 sion Experiments, Provincetown, Mass. 



Plate 11 

 Cranberry bog showing horizontal cloth screen to catch drop of wind-borne gipsy 

 moth larvae. Tanglefoot had not been apphed to screen. 



