BUREAU OP ENTOMOLOGY. 247 



natural enemies enormously increased the multiplication and de- 

 structiveness of this scale insect, and that therefore one of the effec- 

 tive means of controlling this scale is to control the ant, as has 

 been demonstrated similarly in the case of the mealybug in Cali- 

 fornia, referred to above. 



Studies or greenhouse insects. — The spreading and penetration 

 qualities of various contact insecticides employed in the control of 

 insects occurring in greenhouses, with especial reference to the effect 

 of these solutions on the plants, if applied to the soil for subter- 

 ranean pests, have been under study and a considerable amount of 

 data relative thereto assembled. The life history of the chrysanthe- 

 mum aphis has been worked out and the value of water under pres- 

 sure as a means of controlling the red spider determined. Several 

 manuscripts dealing with important injurious greenhouse insects are 

 in the course of preparation. 



Mediterranean fruit fly and melon fly. — Under the Mediter- 

 ranean fruit fly and melon fly quarantine the following fruits and 

 vegetables are inspected and certified as a condition of their ship- 

 ment from Hawaii to the mainland of the United States: Bananas 

 of the noncooking type, pineapples, taro, and coconuts. Provision 

 is also made for the certification for movement to the mainland of 

 other fruits and vegetables when it can be shown to the satisfaction 

 of the Department of Agriculture that such fruits and vegetables 

 in the form and manner in which they will be shipped are not and 

 can not be a means of conveying either the Mediterranean fruit fly 

 or the melon fly. This work is a continuing work, except as to 

 changes which may be made from time to time in the list of fruits 

 the export of which is permitted under the direction and super- 

 vision of the Federal Horticultural Board in cooperation with this 

 bureau. 



The studies of introduced parasites have been continued during 

 the year, and a number of very important biological facts have 

 been determined which have added much to the knowledge of the 

 problem of control of fruit flies by these introduced parasites, and 

 have wide bearing on the subject of parasitic control of injurious 

 insects. A number of technical papers on this subject have been pub- 

 lished during the year. Notably in the case of ooffee and to a cer- 

 tain extent also in the case of edible tropical fruits, the work of the 

 fruit fly has been very materially checked by these intix)duced para- 

 sites. 



EXTENSION AND DEMONSTRATION WORK. 



By act of Congress, under provisions of the food-production act 

 to stimulate agricultural production, funds were made available 

 for this bureau to disseminate information, by demonstration or 

 otherwise, as to methods of preventing the loss due to insects and 

 for increasing the production of honey. This work has been placed 

 under the supervision of Mr. J. A. Hyslop and has been carried on 

 in cooperation with the States Relations Service and with the State 

 agricultural colleges and experiment stations. Special field agents 

 in entomology have been appointed and are reinforcing the State 

 entomological forces and assisting the county agents in the several 

 States. 



