PROGRESS REPORT ON THE EUROPEAN CORN BORER 
61 
Table 18. — Extent of injury and infestation by the European corn borer in 
beans, New England area, 1922 
Field 
Locality (Mass.) 
Date 
examined 
(1922) 
Num- 
ber of 
plants 
Plants showing 
injury 
Plants contain- 
ing larvae 
Larvae per in- 
fested plant 
No. 
Num- 
ber 
Per 
cent 
Num- 
ber 
Per 
cent 
Aver- 
age 
Maxi- 
mum 
1 
July 11 
July 12 
July 13 
July 13 
July 13 
July 17 
July 12 
Julv 12 
July 12 
July 11 
200 
500 
200 
200 
500 
200 
200 
300 
200 
200 
11 
20 
30 
15 
8 
7 
1 
4 


5.5 
4.0 
15.0 
7.5 
1.6 
3.5 
.5 
1.3 
.0 
.0 
5 
19 
30 
14 
8 
7 
1 
3 


2.5 
3.8 
15.0 
7.0 
1.6 
3.5 
.5 
1.0 
.0 
.0 
1.0 
1.3 
1.3 
1.2 
1.0 
1.0 
1.0 
1.0 
.0 
.0 
1 
2 
3 
Do 
Do 
4 
3 
4 
5 
Do 
2 
1 
6 
1 
7 
8 
"Winchester 
Do 
1 
1 
9 
10 
Woburn 
Do 


Total 
2,700 
96 
87 
3.55 
3.22 
1.18 
Spinach 
The occurrence of corn-borer egg clusters on the leaves of spinach 
was very general during 1922-23 in the Boston area. In nearly every 
spinach field examined, egg clusters were found on the leaves, usually 
involving less than 1 per cent of all the plants. Usually the spinach 
was harvested before the larvae hatched or became large enough to 
injure the plants, but where harvesting was delayed, borers were oc- 
casionally found in the leaf stems. Xo commercial injury resulted to 
spinach in any instance under observation. 
Peppers 
The stalks and fruits of sweet and hot varieties of peppers are 
very susceptible to corn-borer attack. In the Boston area during 
September and October, 1922, every field of peppers examined showed 
conspicuous evidence of damage through the medium of broken- 
over plants. In three fields where detailed examinations were made, 
the percentage of plants injured ranged from 18 to 97, and 52 to 76 
per cent of the fruits had been injured by the borer. In these pepper 
fields, in instances where the stalks became broken over before the 
fruit had fully developed, there occurred a cessation of growth to 
the fruit which caused a reduction in yield of marketable peppers. 
Much of the infested fruit was unfit for sale, but the proportion of 
actual loss from this cause varied according to the use for which the 
peppers were intended. 
Potato 
The stalks of potato have commonly been found infested (fig. 17) 
in Massachusetts. In two fields where detailed examinations were 
made during late July, 1922, an average of 18 and 62 per cent re- 
spectively of the plants were found to contain the borer. Although 
such injury resulted in quite an extensive breaking over of the 
stalks in some fields, it did not appear to affect the successful for- 
mation of tubers. No economic loss resulted in any instance under 
observation. 
