Dec, 1916.] Gastrophilus h^morrhoidalis Linn^us. 253 



EXPLANATION OF PLATES. 



Plate 13. 



Fig. I. Dandelion rosette showing young buds at the time when the 

 egg punctures are made. 



Fig. 2. Dandelion bud showing egg puncture through the involucre ; 

 also blackened spots formed by the milky fluid of the dandelion which oozes 

 through the egg punctures and hardens on the outside. 



Fig. 3. Eggs in situ. 



Fig. 4. Interior of flower head showing the work of the larva. 



Plate 15. 



Fig. I. Deformed dandelion flower (side view). 



Fig. 2. Deformed dandelion flower (looking into the head). 



Fig. 3. Adult. 



Fig. 4. Work of adults on a dandelion leaf. 



Fig. 5. Cocoons. 



NOTES CONCERNING GASTROPHILUS H^MOR- 

 ROIDALIS LINN^US (DIPT.)' 



By R. R. Parker, 



Bozeman, Mont. 



While studying the bionomics of the Rocky Mountain spotted 

 fever tick in the Powder River Valley in eastern Montana, during 

 the season of 1916, the vi^riter was able to make several incidental 

 observations on certain pests of cattle and horses. The most in- 

 teresting of these concerned the nose fly, or redtailed bot, Gastrophilus 



1 Contribution from the Laboratory of the Montana State Board of Ento- 

 mology, Bozeman, Montana. 



