116 BULLETIN 1476, U. S. DEPARTMENT OF AGRICULTURE 
PHOTOTROPISM 
Repeated observations in New England with various types and 
colors of lights have failed to show that Pyrausta nubilalis moths 
were attracted to artificial lights to any extent, even though these 
observations were carried on in fields where the moths were very 
numerous and during their seasonal period of greatest activity. Gas- 
oline and kerosene lanterns, acetylene lights, and electric lights of 
white, yellow, blue, green, red, and violet were used in these experi- 
ments. During June, 1920, a gasoline trap lantern was suspended 
8 feet above the ground and run for 20 consecutive nights in a corn- 
field at Watertown, Mass., where hundreds of these moths were in 
flight. During this period 87 moths were captured, consisting of 
57 males and 30 females. This result was typical of similar experi- 
ments in which were used kerosene trap lanterns with yellow, white, 
blue, green, and red colored globes at distances of from 2 to 8 feet 
above the ground. Practically the same results were obtained with 
uncolored acetylene lights and with electric lights of white, yellow, 
blue, green, red, and violet. Three 100-candlepower nitrogen bulbs 
were used in each of the electric trap lights. Judging from the 
comparative number of moths captured at the different colored lights 
a slight preference was shown for white and yellow lights. The 
proportion of males captured usually was greater than that of the 
females. Most of the latter were gravid. 
Little difference was noted between the comparative attractiveness 
of moving and stationary white lights. 
Jablonowski 12 records an observation by L. Baross, of Bankut, 
Hungary, in which 80 per cent of the total Lepidoptera captured at 
acetylene trap lights during the period from June 24 to July 7, 1904, 
were P. nubilalis moths. The exact number of moths captured and 
the proportion of sexes were not recorded. 
CHEMOTROPISM 
The moths were not attracted to various sirups, fresh or decaying 
fruit, honey, stale near beer, or to various aromatic oils. These baits 
were placed in wire-screen cylinders and inclosed in Shaw moth 
traps, the sides of which were coated with sticky tree-banding ma- 
terial in such a manner that any moths attracted to the bait would 
be captured. The traps were suspended in cornfields where the 
moths were numerous, but with negative results. 
SEXUAL ATTRACTION 
Although it is apparent that the attraction between the sexes of 
Pyrausta nubilalis must be highly developed, the phenomenon of 
assembly does not appear to be as pronounced as that exhibited by 
many other Lepidoptera. Only occasional males were attracted, at 
any hour during the day or night, to large screened inclosures in 
the laboratory yard at Arlington, Mass., where several hundred fe- 
males were emerging daily, although large numbers of males were 
present in the immediate Vicinity. In field tests seven wire-screen 
assembly cages containing newly emerged virgin females were erected 
in fields where the moths were numerous. Fresh virgin females 
were placed in the cages at intervals of two or three days and the 
12 See footnote 1. 
