﻿NOTES ON CALIFORNIA THYSANOPTERA I 



Euthrips tritici (Fitch) 

 (Euthrips occidcntalis Pergande.) 

 This is the most common species in Southern California, being present in 

 nearly all the wild flowers and many of the cultivated ones. The differences 

 indicated for occidcntalis are not very marked ; about the most constant differ- 

 ence is in the relative lengths of the fourth and fifth antennal segments, and 

 even these relative lengths are not always constant. There is a wide specific 

 variation in color, from extremely light lemon yellow to light brown ; the 

 cephalic and thoracic spines, also, present a specific variation in length. These 

 variations make it very diflficult to assign any definite characters to either 

 form, which could distinguish it from the other; owing to these variations, 

 and to the inconstancy of the relative lengths of the fourth and fifth antennal 

 segments, it hardly seems justifiable to maintain these as two distinct species, 

 although they have been so thus far. Occidcntalis certainly does not have 

 more than varietal value. 



Thrips tabaci, Lindeman 

 Specimens belonging to this species were taken by the writer on flowers 

 of onion and also of chilicote (Micrampelis macrocarpa) . This species is not 

 very abundant, however, in this locality, because of the fact that not many 

 onions are raised here. Larval and pupal forms were taken together with the 

 adult forms. 



Thrips niadronli Moulton 



Specimens evidently of this species were taken by the writer on Umbellu- 

 laria, Ceanothus. and on Sambucus glauca. Their general color ranges from 

 light lemon yellow to brown, a few very dark brown. The description of the 

 species by Moulton is : color uniform brown, usually dark brown. The speci- 

 mens in this collection show, also, a considerable variation in the size of the 

 individuals. 



Heliothrips fasciatus Perprande 



Numerous specimens of this have been sent to me from Santa Paula, Cal., 

 by E. O. Essig, taken from pine foliage ; others have been taken by the writer 

 on pine foliage in this locality ; also, from Lotus glaber, and from the flower 

 end of ripe apples brought from Chino, Cal. The wings are very long, reach- 

 ing much beyond tip of abdomen ; posterior longitudinal vein branches from 

 anterior just beyond distal margin of basal white area. Femora are black. 



