75 



immense numbers have been handled each year since. The possibility 

 of introducing this species into Hawaii in large quantities has been 

 considered and some attempts have already been made to do so, but 

 apparently it has not become established. There are difficulties 

 connected with the transportation ; storage for ten weeks or more 

 after removal from the natural hibernation quarters causes a high 

 mortality among the Coccinellids ; moreover they are not a tropical 

 species and might not survive in Hawaii. In view of the importance 

 of its activites in California, however, it is thought that further 

 attempts should be made to add it to the beneficial species that have 

 already been introduced into Hawaii with very great advantage. 



Fernald (H. T.) & Bourne (A. I.). Department of Entomology.— 

 31st Ann. Rcpf. MassaclmscUs Agric. Exjpt. Sta., Boston, Mass., 

 Parts i and ii, Pub. Doc. 31, January 1919, pp. 39a-43a. 

 [Received 29tb December 1919.] 



Tests of standard insecticides to determine their action and the 

 causes of burning of foliage have been continued. Pure materials 

 have previously been tested and commercial brands are now being 

 tried in the same way. Calcium arsenite cannot be recommended 

 for ordinary use as too many precautions are necessary for safety ; 

 the study of calcium arsenate to replace it has therefore been under- 

 taken. 



Several proprietary insecticides have been tested during the year. 

 The most successful of these was " Plant Lice Killer " for use 

 against Aphids. The oily nature of this mixture makes it difficult 

 to prepare, but when properly mixed and maintained it is effective, 

 1 part to 15 or 20 of water killing practically all the insects reached 

 and 1 to 30 killing about 90 per cent, of them. At a strength of 

 1 : 15 only the most delicate foliage was injured ; with 1 : 20, no 

 injury was noticed. 



Bordeaux mixture, Pyrox and Insecto were tested during the 

 summer of 1918 to determine their value against potato pests, nicotine 

 sulphate 40 per cent, in 1 to 800 dilution being added to each. The 

 last-named had rather poor suspension qualities, giving poor 

 distribution and clogging the nozzle. Home-made Bordeaux gave 

 the best distribution and Pyrox was nearly as good. Flea-beetles 

 were well controlled by all three materials, the nicotine sulphate 

 combining with them without difficulty. 



E* The work on digger wasps as parasites has progressed, but no results 

 can as yet be reported. Eemedies against the onion maggot 

 [Hylemyia antiqua] were practically limited in 1918 to tests of traps 

 for the adult flies. Six traps placed in an area of about one-fourth 

 of an acre captured about 48,000 ffies, of which about 4,500 were 

 those of H. antiqua during May and June. These experiments will 

 be continued. 



With regard to the codling moth [Cydia pomonella] it had been 

 decided that no second brood is present in Massachusetts except for 

 a few scattered individuals. A second brood of considerable size was 

 noticed however in 1918 and it has been decided to carry the 

 investigations further. 



