210 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 2 



President Forbes: The third paper of the series is "Insects of 

 the Year in Iowa," bv Mr. K. L. Webster. 



INSECTS OF THE YEAR IN IOWA 



By R. L. Webster, Ames, loica 



The following notes on insect injuries in Iowa during the past year 

 are taken from office correspondence of Prof. H. E. Summers and from 

 observations of the writer. 



The English grain louse, Macrosiplium granaria, which was so com- 

 mon in Iowa and IMinnesota last year, has been hardly noticeable dur- 

 ing the past season. Early in the spring it looked as if this species 

 might again threaten the wheat and oat crop, as it did last year. 

 Winged forms of Macrosiplium granaria appeared in plots of winter 

 wheat at Ames on April 11th. Just where these winged forms came 

 from is unknown. Certainly they did not come from the young 

 nymphs on the wheat, for only the very young progeny of the 

 wdnged forms themselves were found. Had the species spent the win- 

 ter on the grain there should have been some pupa? or older nymphs 

 present. Moreover, the plots had been examined almost daily for sev- 

 eral weeks preceding and no traces of aphids of any species had been 

 found. The wind had been in the south for two or three days previ- 

 ous, so it is possible that the insect had been blown in. Were the time 

 later in the spring, a migration from one food plant to another would 

 be probable, but at this time of the season I do not know from what 

 plant the aphid would migrate. Last year I found the winged forms 

 of this species at Albert Lea, Minnesota, May 20th, the first appear- 

 ance of the insect in any form in Minnesota that spring. These 

 winged forms had also apparently only recently reached the grain 

 from some other situation. 



The spring grain aphis, or green bug, Toxoptera graminum, was 

 also scarce in Iowa this year. Not until July 8th were any specimens 

 found, at which time some apterous forms appeared on volunteer oats. 

 These were found along the right of way of the C. & N. W. Railway, 

 west of Ames. What was probably the same species was found at 

 Council Bluffs on August 6th, but nowhere else in the state. Neither 

 this nor the preceding species were found in southern Iowa in ]\Iarch, 

 when a thorough search was made for them in fields of winter wheat. 



The wheat head army worm, Heliophila alhilinea, was very com- 

 mon over the state during July, especially upon timothy. The stalk 

 borer, Papaipema nitela, was also common during the summer, bor- 

 ing in corn and oats. The clover seed caterpillar, Enarmonia in^ 



