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were found in large numbers, having survived a 5-montJis' submergence. 

 Penisia vaccinii {Cecidomyia oxycocrana). cranberry tip worm, was 

 investigated during the year. The tips of the plants were examined 

 before they showed injury, while the bog was in full bloom. Eggs 

 and larvae in various stages of development were found. Three weeks 

 later the infested tips had dried up and the larvae had disappeared 

 without leaving cocoons. It was found that pupation occurred in the 

 sand at the base of the plant. From 50 or 60 bogs examined, the 

 following conclusions were readied : (1) That flooded bogs, if not 

 resanded before 1st May, were usually more seriously injured than 

 strictly dry bogs ; (2) that flooded bogs which had been resanded in 

 the previous autumn or in the spring before 1st April, were much less 

 injured than those not resanded, most damage occurred in those not 

 resanded for two years or more : (3) the " Late Howe " variety showed 

 more injury than did the " Early Black " ; (4) no bog showed great 

 tip worm injury where there had been severe frost ; (5) resanding 

 every other year should be recommended as a control measure. 

 General observations were made concerning the Tortricid, Rhopobota 

 vacciniana, Pack. It was concluded that winter-flooded bogs which 

 could not be reflooded in June must either have the flood retained 

 late enough to kill the eggs (imtil about 20th June), or else be sprayed 

 with arsenicals. The use of a sweetened spray would involve 

 considerable difficulties, owing to the long hatching period during 

 which the poison must remain on the plants. This insect does not 

 seriously infest bogs without winter floods and, if the latter were 

 omitted, would probably in time be controlled by weather conditions 

 and natural enemies. Omission of winter flooding, however, results 

 in an increase of the Pyi'alid, Mineola vaccinii (cranberry fruit worm). 

 Late winter flooding seems to be the only reUable method of dealing 

 satisfactorily with this insect, but a better treatment is desired, 

 because the water does harm when held late every year. Experiments 

 with insecticides have given no practicable results. For dry bogs, 

 the possibihty of stai'ving out the insect by destroying the bloom in 

 seasons of hght crop is under consideration. The study of the natural 

 enemies of the fruit worm was continued and the following species were 

 bred in large numbers : Phanerotoma tibialis, the hving young of 

 which are inserted into the eggs of the host ; Pristomeridia agilis, 

 which inserts its eggs into the larva of the fruit worm ; and Tricho- 

 gramma mimda. The last-named species undergoes its entire 

 development in the egg of the host, the adult emerging in July and 

 August. About 56 per cent, of the fruit worm eggs on dry bogs were 

 destroyed by this parasite. The majority of P. tibialis on flooded 

 bogs perish during the winter and it may be advisable to attempt 

 to keep them under artificial conditions by collecting fruit worms 

 during the summer and allowing them to pupate. Submergence tests 

 with the fi-uit worm showed that the pupa has great ability to resist 

 drowning, apart from any protection afforded by the cocoon. The 

 latter became completely filled with water in about five days ; cocoons 

 kept in stagnant water did not. survive, while those submerged in 

 sacks suspended in a pond were aUve after 25 days. 



