70 
Psyche 
[June 
only the collections from Juglans A and B in 1958 and i960 are 
recorded graphically. In Part I of this series (Bailey, 1963) Figures 
I and II show the weekly rainfall and the weekly temperature aver- 
ages for these two seasons. 
Depending on climatic conditions this species is active from early 
May (May 8, i960) into early October (October 11, 1958). On 
one occasion they were so abundant on Juglans A that 1 10 were 
collected in five minutes (September 7, 1958). 
In 1957 a single leaf yielded 48 (31 99 and 17 cf cf )• Since the 
leaves of Juglans are large and pinnately compound, this is actually 
not a large number. At times, I am sure, the number on such a leaf 
would far exceed this. Usually these leaves consist of 15 leaflets 
(7-17 according to Fernald, 1950). These leaflets are oblong-lanceo- 
late with acuminate tips and broadly rounded bases. The veins are 
prominent on the lower surface and both surfaces are covered with a 
velvety pubescence. An individual leaflet may be more than 12 cm. 
long and nearly 6 cm. wide. The entire compound leaf is often 
about 24 cm. wide by over 50 cm. long. The Tingids generally feed 
on the lower surface but may be seen infrequently on the upper side 
of the leaflet in heavy infestations. 
Experimental marking of this species gave some promising results. 
On August 5, 1958, 100 specimens were marked with a yellow 
plastic paint by placing a dot on a hemielytron with a fine brush tip 
(or dry grass stem) while the insects were on the leaves of Juglans 
A. For several days thereafter marked specimens were seen on the 
host plant until as late as August 31st. Again on September 3rd 
more than 525 lace bugs on Juglans A were marked in the same 
manner with white paint to distinguish them from the earlier lot. 
Many of these were observed still feeding on the host on September 
7th, and as late as September 21st marked specimens were easily 
located on the foliage. Although little collecting was done in 1959, 
a single marked specimen that had overwintered was recovered early 
in the season. At least under some conditions this plastic paint will 
adhere well and it is apparently non-toxic as used. Also, it is available 
in many colors and is sold inexpensively in small bottles. Further 
experimental use is indicated by the results of these preliminary 
efforts. 
Figures I and II reveal an interesting contrast in the seasonal 
population trends of Corythuca juglandis (Fitch) on Juglans A in 
1958 and i960. In 1958 it was mid-May before leaf development 
and temperatures favored mass emergence of the hibernating lace bugs. 
Although temperature fluctuations were marked throughout the season, 
