Captures of maleTrichoplusia ni(Hübner) in cylindrical electric-grid traps baited with synthetic sex pheromone, declined with increasing elevation from 2 to 10 ft above ground. Collections ofManduca sexta(L.) in similar traps baited with virgin females were not affected significantly by the same range of elevations. Collections ofT. niwith 12-, 18-, and 24-in.-diam grids, but with the same electrode spacing (½ in.), did not differ significantly; however, ¼-in. electrode spacing was 38% more effective than ½-in. spacing on the 12-in.-diam grids. The largest number ofM. sextamoths was caught by the smallest-diameter grid, and the size of collections decreased as the diameter increased.