4 BULLETIN 778, U. S. DEPARTMENT OE AGRICULTURE. 



greatly produced, with a length about five times its diameter. Ovipositor nearly 

 as long as the abdomen, the, terminal lobes narrowly oval, tapering. Other 

 characters presumably as in the opposite sex. 



LIFE HISTORY. 



The female midge, with her long ovipositor, places small yellowish 

 eggs just under the sepals of the flower buds or between the folded 

 leaves of the leaf buds. Under favorable temperature conditions 

 these eggs hatch in 2 days, and the young larvae or maggots immedi- 

 ately attack the buds, extracting the sap and eventually causing the 

 petals and leaves to dry up and die. (Fig. 2.) They grow very 

 rapidly, reaching maturity in from 5 to 7 days, and, when full 

 grown, work their way out of the buds and fall on and enter the 

 ground where they construct small silken cocoons (fig. 1, D) in which 

 they pupate. Adults appear in from 5 to 7 days, and shortly after 

 deposit eggs for the next generation of larvse or maggots. In con- 

 finement the life of an adult is from 1 to 2 days. The total cycle, 

 therefore, under greenhouse conditions, is from 12 to 16 days. About 

 85 per cent of the adults reared in cages were females. 



SEASONAL HISTORY. 



Although larvse or maggots have been observed injuring buds as 

 early as February 22, under normal conditions they do not appear in 

 injurious numbers until June or July. In Washington adults were 

 reared in early May from larvse which pupated in November. Dur- 

 ing the warm summer months the generations may mature every two 

 weeks, and overlapping of broods probably takes place. Larvse were 

 especially injurious at Colgate, Md., during two periods of the year, 

 namely, from the latter part of May to early July and from early 

 September to November 1. On the approach of cold weather the 

 stages are slightly prolonged, and about the latter part of November 

 the larvse enter the ground and construct overwintering cocoons. No 

 injury has been reported during winter. 



FOOD PLANTS. 



Roses, especially the hybrid teas, are apparently the only plants 

 attacked by this insect. It has been recorded as infesting the Radi- 

 ance, Hadley, Russell, Killarney, Ophelia, Hoosier Beauty, Shawyer, 

 My Lady, American Beauty, Uncle John, Joe Hill, Kate Moulton, 

 Bridesmaid, Liberty, Richmond, Mrs. John Laing, Meteor, Madam 

 Chatenay, Ivory, Golden Gate, Wooten, La France, and a sport of the 

 latter, the Duchess of Albany. 



EXPERIMENTS IN CONTROL. 



At the suggestion of Prof. E. N. Cory a series of experiments, in 

 which the following combinations were used as sprays, was conducted 

 to determine the value of molasses in catching the larvse, thus pre- 



