306 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 13 
plants. The following biological observations on the species were 
made possible by the collection of a number of eggs in 1917 which, 
when reared to maturity, proved to be those of L. submucida. 
Table I gives a comparison of the numbers collected during the past 
four seasons. An attempt was made to make the collections uniform 
by collecting nightly from the opening to the close of the season of 
flight. During the 1916 season, tree and food plant collections were 
neglected for light collections and in 1919 the reverse was true, light 
collections being neglected for food plants, so on the whole, the col¬ 
lecting is thought to be somewhat uniform for the four years. 
4 
Table I. —Summary of Total Collections 
Species 
1916 
Brood C 
1917 
Brood A 
1918 
Brood B 
1919 
Brood C 
Total 
L. crassissima. 
3,412 
10,244 
856 
1,143 
15,655 
L. rubiginosa. 
104 
5,176 
802 
109 
6,191 
L. futilis. 
1,192 
3,217 
381 
890 
5,680 
L. rugosa. 
571 
1,301 
188 
319 
2,379 
L. implicata. 
395 
214 
131 
87 
827 
L. vehemens. 
77 
341 
11 
8 
437 
L. submucida. 
11 
4 
1 
2 
18 
31,187 
Life History 
Adults 
Period of Flight.—The flight season begins as early as April 18 in 
the vicinity of Manhattan, and with the species concerned may last 
until the middle of August. The maximum period of flight occurs in 
May and June, except in the case of L. submucida , which is a late flying 
species that pupates in June and July and flies soon after becoming 
adult. It does not pass the winter in the adult stage as do the other 
species. In general, it can be said that L. futilis, L. rubiginosa, and 
L. vehemens appear first with L. crassissima and L. rugosa soon follow¬ 
ing. Specimens of L. implicata have not been taken before May 6, 
and L. submucida does not fly until July. Table II shows the earliest 
and latest dates on which the species have been found either at lights 
or food plants. 
Table II. —Period of Flight 
Species 
Earliest 
collection 
Last 
collection 
Period of flight. 
Days 
T. futilis. 
April 18 
July 21 
94 
L. rubiginosa. 
April 18 
Aug. 8 
112 
Jj. vehemens. 
April 18 
June 23 
66 
L. crassissima. 
April 22 
Aug. 17 
117 
L. rugosa. 
April 23 
July 12 
80 
L. implicata. 
May 6 
July 21 
76 
L. submucida. 
July 7 
Aug. 17 
41 
