IOWA ACADEMY OF SCIENCE 
301 
Both were more ; abundant than usual during the season of 1912, due un- 
doubtedly to a favorable season. The cutworms destroyed many cab- 
bage and tomato plants by cutting them- off one or two inches below the 
ground. One man who makes a specialty of raising cabbage estimated 
his loss at from 25 to 30% of the total number of plants set out. On an 
adjoining plot, especially noticed by the writer, out of 500 tomato plants 
less than 50 remained three days after they were transplanted. On in- 
vestigation one to five cutworms were found around each plant ex- 
amined. Of course this unusually high percentage of loss was due to 
some condition in this particular plot especially favorable to the cut- 
worms. In the strawberry beds the maybeetle larvae did considerable 
damage by cutting the plant just below the crown. From the present 
observations it would seem that this species might be of considerable 
value to the market gardner and fruit growers. 
Before estimating the economic value of the species we must take into 
consideration the fruit consumed. During the one day’s observation 
the young were fed 19 cherries out of 217 morsels of food, or 8.75%. 
Spiders formed 8.29% of the total and miscellaneous worms and in- 
sects the remainder. One fact noted in connection with the feeding of 
the cherries was that the male fed practically all of them, 16 out of 19 
being credited to him. The larger portion of these were taken from the 
nest tree, many of them being taken from the tree and fed during visits 
to the nest with insect food. The most striking fact about the latter is 
the low percentage of fruit consumed considering its availability. It 
would seem that this amount represents the maximum fruit eating 
proclivity of this species, at least in regard to the nestlings, since it 
would be difficult to conceive of more favorable conditions for its use. 
The remaining 22.13% of miscellaneous insects consists of such small 
numbers of each species that their destruction has little economic im- 
portance. Their use as food indicates that the birds have no aversion 
to them. It might also warrant the conclusion that if for any reason 
any of these forms should increase in numbers enough to become eco- 
nomically important, the Brown Thrashers would help keep them in 
check. 
Summing up these facts the balance seems to be strongly in favor of the 
birds. Against the actual loss caused by the consumption of fruit to 
the extent of 8.75% of the food, can be placed the destruction of in- 
jurious insects amounting to 60.82% of the total. As previously stated 
the conditions were very favorable for the use of fruit as food, and this 
makes it probable that the amount of fruit consumed would rarely 
exceed 10% of the total food supply. In determining the economic 
