214 
IOWA ACADEMY OP SCIENCES. 
CONTRIBUTIONS TO A KNOWLEDGE OF THE THRIP- 
ID^ OF IOWA. 
ALICE M. BEACH. 
This paper represents the results of a study of some of the 
Thripidse of Iowa, and is based upon an examination of mate- 
rial found in the collection of the Iowa Agricultural College, 
some specimens kindly loaned by Miss Emma Sirrine, Messrs. 
F. A. Sirrine and C. W. Mally, and some in the writer’s own 
collection. Descriptions of seven new species and three new 
varieties are herewith presented, including a new species of 
Phloeothrips described by Prof. Herbert Osborn. The descrip- 
tions are preceded by an artificial key, arranged to aid in the 
identification of all the described Iowa species known to the 
author. The table for the determination of genera is substan- 
tially that found in Comstock’s Introduction to Entomology, 
pp. 125-127. The writer is indebted to Mr. Pergande for an 
outline of the characters of Euthrips, and is under special obli- 
gations to Professor Osborn for valuable aid in the prosecution 
of this work which has been done in the Entomological Depart- 
ment of the Iowa Agricultural College. 
TABLE FOR DETERMINATION OP GENERA. 
A. Last abdominal segment in both sexes elongated, narrow, tubular; 
both pairs of wings similar, veinless, margins equally ciliated; 
maxillary palpi two-jointed; borer in female absent 
Sub-Order I. Tubulifera. 
B. Contains but a single family Earn. I. Tubuliferidse. 
C. Contains but a single genus ___Gen. 1. PhlcBothrips. 
AA. Last abdominal segment not elongated and tubular in both sexes; 
both pairs of wings unlike in structure, front wings always veined; 
margins unequally ciliated; maxillary palpi three- jointed; borer 
in female present Sub-Order II. Terebrantia. 
B. Females with borer curved upwards Fam. II Stenopteridae. 
BB. Females with borer curved downwards. _ -Fam. III. Coleoptratidae. 
