108 THE REPORT OF THE No. 36 



Food Plants. 



Sour cherries, especially Montmorency and Morello, are the favorites, but late 

 sweet cherries are also infested. Early Richmond (a sour variety) and early sweet 

 cherries are only to a very small extent injured, probably because they are nearly 

 ripe before the eggs are laid and because the flies prefer to lay eggs in greeii cherries 

 or those just beginning to turn. Wild sweet cherries, offsprings of cultivated sweet 

 varieties, are also attacked, hut no other kinds of wild cherries were found with any 

 maggots in them. 



Nature and Extent of the Injury. 



The injury is caused by the larvae — little white maggots — ^tearing the pulp 

 around the pit with the hooks that serve as jaws and absorbing the juice. This soon 

 renders the interior unsightly and the cherry unfit to eat. The surface above where 

 the feeding is done often collapses. Wormy cherries are subject to the Brown Rot 

 disease, and then spread this to neighboring cherries. Moreover the sale of wormy 

 fruit spoils the market for good cherries. 



Many orchards in the Niagara districts are infested. In some the loss is very 

 small, in other it is very great. About one dozen fair-sized orchards have been 

 visited that had each from 30 to 90 per cent, of the fruit wormy. There is no doubt 

 at all that the insects are very important and need to he comhated. , 



The Plum Curculio larva has a distinct brown head, and a stout curved, creamy 

 white body. The Cherry Fruit-fly larva has no head, a pair of black hooks taking 

 the place of a head. The body is not curved and tapers strongly towards this end, 

 the anal end being blunt. The colour varies from glossy white to light yellow in both 

 species. 



The adults of B. fausta begin to emerge in Niagara the first week in June, 

 that is a few days before the early Richmond cherries have begun to -show any l-ed. 

 R. cingulata adults are approximately a week later, not beginning to emerge until 

 about the lOth or 12th. The majority of R. fausta came out this year between June 

 Stli and 13th, and of R. cingulata between June 16th and 21st, that is a little over a 

 week later. 



The average length of life of both species is a little less than one month, pos- 

 sibly not more than three weeks. A few adults, however, live somewhat longer. 

 There are more females than males, though towards the end of the season there are 

 at least five males of cingulata to one female. This is not true of fausta, the females 

 being iri the majority even late in the season. 



Length of Time From Emergence to Egg Laying. 



This is difficult to determine, but from a number of experiments was found to 

 bo somewhere between ten and fourteen days. 



The eggs are laid hy the sharp sting-like ovipositor just beneath the skin. They 

 can easily be seen with a hand lens by cutting across the cherrv' just below the sur- 

 face. Eggs of hoth species are white and nearly elliptical. In large cages 44 

 larvfe were the most obtained from any one fly. but a dissection of mature ovaries 

 showed as many as 240 eg^^s either fully formed or clearly distinguishable. Others 

 would doubtless be formed as these were being laid. It would not be surprising 

 if one fly laid 300 eggs or more. The operation of laying requires less than thirty 



