338 AXXTAT. REPORTS OF DEPARTMENT OE AGRICULTURE. 



Avith insoct problems in Calit'orniH l)ave been piiblisbed (hiring the 

 year. 



Crriuis FKUiT ixsects in Florida. — The work under this project 

 has been a continuation of that described in the previous report. 

 The vahio of the dust method for control! in^r rust mites has been 

 determined and many demonstrations have been conducted through- 

 out the State. Cooperative work with the Bureau of Plant Industry 

 has been carried on for the purpose of developing a combination 

 spray which will be effective against insects as well as plant diseases. 

 x\s in the past, considerable attention has been given to the control 

 of the citrus white fly and the scale insects which commonly infest 

 citrus plants in Florida. 



Investigations or insects affecting mango, guava, avocado, and 

 OTHER subtropical FRUITS. — During the year the insects infesting the 

 plants listed above have been studied at the Miami station. A paper 

 ' has been published on the banana root-borer, and several papers are 

 in course of preparation describing the life history and methods of 

 controlling the principal injurious insects infesting the avocado, 

 mango, and papaya. The work of this laboratory has been in close 

 cooperation Avith the Federal Horticultural Board in an effort to safe- 

 guard against the introduction of insects injurious to tropical and 

 subtropical plants. 



Studies of greenhouse insects. — The Avork under this project has 

 been for the most part limited to the study of the strawberry root- 

 Avorm, an insect Avhich in recent years has developed into a serious 

 pest to roses groAvn under glass. This insect is noAV established in 

 Avidely separated localities and is reported to haA'e been responsible 

 for the loss of some $70,000 in one county alone in the State of 

 Pennsylvania during the present year. In order to study this insect 

 under field conditions a temporary station has been located in Penn- 

 sylvania, and active Avork is being conducted in collaboration witli 

 the Pennsylvania State Department of Agriculture. 



An investigation of the chrysanthemum midge has been completed, 

 and a bulletin (Department Bulletin 833) has been published, giving 

 general information on the life history, habits, and methods of con- 

 trolling this chrysanthemum, pest. 



Mediterranean fruit fly and melon fly. — As heretofore, the 

 work at the laboratory at Honolulu has consisted primarily in the 

 inspection and certification of pineapples, bananas, coconuts, and 

 taro for shipment from Hawaii to the mainland. Further studies 

 have been made to determine the effectiveness of parasites and other 

 natural enemies in controlling the Mediterranean and melon fruit 

 flies. In addition to the fruit-fly problems, a study of the principal 

 in.'^ect enemies of the algaroba bean — an important stock food — has 

 been undertaken in collaboration Avith the Office of Stored Product 

 Insect Investigations. 



Geographical distribution of fruit flies. — A survey was made in 

 Spanish Honduras to determine the injurious fruit flies and tropical 

 and subtropical fruit insects Avhich are present in that country and 

 Avhich may enter the United States in shipments of fruit to southern 

 ports. A number of injurious tropical and subtropical insects were 

 found and a report of this trip is in the course of preparation. 



