STRAWBERRY ROOTWORM ON GREENHOUSE ROSES 13 
Sixty adults given fresh leaves twice daily ate 372 of the charac- 
teristic “shot-hole” punctures (fig. 1) the first day, 386 the second 
day, and 325 the third day, averaging 6.2, 6.4, and 5.4 feeding punc- 
tures per adult on the respective days, or an average over the whole 
period of 6 such areas for each beetle per day. It was observed 
to require about six minutes for a beetle to eat one hole in a leaf. 
Further experiments, as indicated in Table 4, gave an average of 
between 4 and 5 feeding punctures per day for each individual. 
TABLE 4.—Amount of feeding by strawberry rootworm beetles during 
September, 1921 
N umber of— Feeding punctures— 
Period Average 
(first and last dates, inclusive) Remarks 
Days | Adults oe ent 
number er a 
Per day per day 
AUISC GILCO SCDbw2 2 sesase ee ee 3 4 645 215 4.57 
SHEVA TOES IS) 05 ee eee eee re ap 4 46 1,103 276 6.00 | 1 dead. 
SEPo LES LOy STS) of al UO a ee 4 947 237 5. 27 0. 
Pepe lincOisepbs 1 4ac eo a es ee 4 43 704 176 4.09 | 2 dead. 
Septet SILO SOpbe Lise e 2k ie: here eee 3 43 528 176 4.09 
Sein S tOlsepba cee sess oe eS a 5 43 463 93 2.16 
SHEPOUES OATHS TS) 0) 7-7 ek hee em ae SO ete 5 43 446 89 2.07 
PROTECTIVE HABITS 
As is characteristic of certain other insects, this beetle at the least 
disturbance folds its legs and antenne under its body, rolls from 
the leaf, and remains motionless on the ground for several minutes. 
This so-called “possum” or death-feigning habit is also protective 
and is more common than the “squirrel” habit, by which they 
escape being seen. If approached during the day, any beetles visible 
on the plants immediately conceal themselves behind leaves, stems, 
stakes, or elsewhere. When one walks through a heavily infested 
house at night he can hear the beetles dropping from the bushes 
about 10 feet ahead, and when the beetles are present in large ° 
numbers the sound is similar to the patter of a gentle rain. The 
coloration of the beetles blends with that of the earth or mulch, and 
it is difficult to locate them on the soil unless they move. 
The beetles do not necessarily reach the ground when they drop 
from the plants, for they are apt to fly at any time during their fall. 
In fact, when within a foot of the soil they have been observed to 
spread their wings and fly to near-by leaves. The range of con- 
tinuous flight appears to be limited, as 30 feet was the maximum 
distance observed. In one house, where the plant tops had been cut 
back and removed during the day, many beetles were seen on the 
_ walls and roof, where they were apparently trying to escape from 
_ the house by making short flights of from 5 to 10 feet at a maximum 
altitude of 10 feet. 
FERTILITY AND PARTHENOGENESIS 
Mating was not observed and males have never been seen among 
the numbers of individuals collected under glass. Peterson (23, p. 
ut 
3. 
i Ps 
