192 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 14 



new variety from a jobber and with them came a "light infestation so 

 that this fall not only the plants he bought but two of his own varieties 

 were infested slightly. 



In many respects the rose midge is like the chrysanthemum midge. 

 Though this insect has been known in the United States since 1887, its 

 outbreaks have been more or less sporadic and probably dependent on 

 the distribution of new varieties which have served as favorite food 

 plants. The last distribution and resulting outbreaks of this pest took 

 place with the dissemination of the popular rose, Ophelia. There is 

 little doubt but that the plants, sent out by one of the several distribu- 

 tors of this variety, were infested with this midge. Ophelia is a fine 

 seed parent and also shows a tendency to ' ' sport' ' easily. Many of its 

 "sports" and seedling offspring are held in high esteem by the florists 

 and are constantly gaining in popularity with the flower-buying public. 

 The reason I have mentioned this fact is that Indiana observations 

 indicate that some of these sports and seedlings show the same susceptibil- 

 ity to the attacks of rose midge that their parent does and there are 

 indications that another outbreak of this insect over wide areas is going 

 to result. 



The greenhouse white fly, because of the range of host plants it attacks, 

 is very troublesome. It is difficult to control, especially when hydro- 

 cyanic acid gas is not used. Florists who have not had experience with 

 this insect often scoff at the idea that it is a serious pest. But many 

 Indiana florists have changed their minds regarding its importance. 

 Those who have attempted to grow semi-hardy perennials like buddleia 

 and bouvardia under glass or those who have lost a crop of indoor asters 

 through its attack do not think it a pest of secondary importance. 

 Those who grow fuschias, salvias, primulas and celestial peppers know 

 that it is no easy task to control white fly. Yet one can find growers 

 of some of its favorite food plants who have little or no difficulty in hold- 

 ing the insects in check, often without resorting to cyanide fumigation. 

 In view of these facts what disposition should an inspector make of 

 plants lightly infested with white fly ? 



Those insects and mites that occur out-of :doors in the northern two- 

 thirds of the United States but have invaded greenhouses, like the red 

 spider, the greenhouse leaf-tier, the rose leaf-roller, and the strawberry 

 root-worm, present an interesting case. The first and the last named 

 become serious pests out-of-doors but the other two do not seem to be 

 nearly as serious pests in the open as under glass. If Indiana experiences 

 are to be taken as a basis, it is safe to assume that both the leaf-tier 

 and leaf -roller have been far more widely distributed through the medium 

 of infested hosts than through the invasion of the greenhouses by moths. 



