Pid 
Of southern species both the cotton worm and the boll worm moths 
are to be found very late in the season, and the writer has seen the cot- 
ton-worm moths in November in great numbers at Ithaca, N. Y., at 
light, after most other insects had been absent from lights, at least 
in any numbers, for weeks. Immense numbers of the moths were 
attracted to the electric lights on the principal streets of the city.’ 
Larve of two important species, the imported cabbage butterfly, 
Pieris rape and the diamond-back moth, Plutella eruciferarum, both 
of comparatively recent introduction, were found during the winter of 
1899-1900 in the last week of November freely feeding after several 
frosts. They were accompanied by the harlequin cabbage bug, J/ur- 
gantia histrionica, which we know to have recently spread northward 
from the Southern States, and by the cabbage looper, Plus/a brassice, 
which has also spread from the south northward, though not in very 
recent times. 
SUMMARY OF CONCLUSIONS. 
The result of recent studies may be summarized briefly as follows: 
(1) That there is a tendency on the part of forms introduced in the 
North from farther South to produce one or more generations in excess 
of the number developed by similar forms native to the region of this 
adopted habitat. 
(2) That as a result these forms remain later in the field than do 
species native to the North. 
(3) That, largely as a result of the above and other habits, in addi- 
tion to greater susceptibility to low temperatures, these southern intro- 
ductions are apt to be destroyed every year in large numbers, their 
residence in their northern homes being, therefore, not strictly per- 
manent. Cold snaps following warm spells during the winter are, ac- 
cording to observation, the most important factors in their destruction. 
ON THE HABITS OF ENTILIA SINUATA. 
By L. O. Howarp. 
This interesting little leaf-hopper, certain of the habits of which 
have been described by Mrs. M. E. Rice, of Coryville, Pa., in Volume 
V of Insect Life (pp. 248-245), is common throughout the eastern 
United States, and may be found upon many different plants, such as 
potato, ragweed (Ambrosia), spikenard (Aralia), Cnrveus altissimus, 
Lactuca spicata, Rudbeckia laciniata, cotton, sunflower, and other 
annual and herbaceous forms. Mrs. Rice studied the eggs, which 
were laid upon the midrib of a leaf of sunflower and began to hatch 
'The exact date was not noted, but it is much colder in that locality than on the 
corresponding date in Washington, there being about a month’s difference in that 
climate in ordinary seasons, and although the event happened many years ago, it is 
remembered that a heavy overcoat worn at the time was very comfortable. 
