8 BULLETIN 778, U. S, DEPAETMENT OF AGRICULTURE. 



during the latter part of October or the first three weeks of Novem- 

 ber, at which season the last generation of larv^se leaves the plants, 

 enters the ground, and constructs overwintering cocoons. If depend- 

 ance is placed on the dust alone, it is imperative that the application 

 be so timed as to be on the soil before the larvae seek winter quarters. 

 No hard and fast rule governing the date of this application can be 

 recommended for all localities, since temperature naturally influences 

 the final disappearance of the larvae. 



PRECAUTIONARY MEASURES. 



The rose midge can be kept out of greenhouses if proper precautions 

 are exercised. Under no condition should infested plants be taken 

 into a house free from this pest. Plants should not be purchased 

 knowingly from firms which carry infested stock, and should be 

 bought with the understanding that they are free from the midge 

 either in the buds or in the soil. Before new stock is placed in a 

 house, all plants should be examined carefully, and suspicious ones 

 destroyed or returned to the shipper. 



LITERATURE CITED. 



(1) United States Depaetment of Agkicultuee, Division of Entomology. 



1888-89. In Insect Life, v. 1, p. 284. 



(2) Webster, F. M. 



1904. Studies of tlie habits and development of Neocerata rliodophaga 

 Coquillett. I"i Bulletin of the Illinois State Laboratory of Natural 

 History, v. 7, art. 2, p. 15, p. 21-23. 



(3) Davis, J. J. 



1912. Report on insects injurious to flowering and ornamental green- 

 house plants in Illinois. In Forbes, S. A., Twenty-seventh Report 

 of the State Entomologist on the Noxious and Beneficial Insects 

 of the State of Illinois, p. 109. 



(4) Felt, E. P. 



1915. Twenty-ninth Report of the State Entomologist on Injurious 

 and Other Insects of the State of New York, p. 131. (University 

 of the State of New York Museum bulletin 175.) 



(5) Hewitt, C. Goedon. 



1915. Report of the Dominion Entomologist for the Year Ending 

 March 31, 1915, p. 33. 



(6) The American Rose Annual. 



1916. Page 63. 



(7) Snodgkass, R. E. 



1917. Some of the important insect pests of Indiana. In State En- 

 tomologist of Indiana, Ninth Annual Report, 1915-16, p. 146. 



(8) Gibson, Arthur. 



1917 Three important greenhouse pests recently introduced into 

 Canada. In Entomological Society of Ontario, Forty-seventh An- 

 nual Report, 1916, p. 120-121. 



o 



