60 THE REPORT OF THE No. 33 



The European Red Mite (Paratetranychus pilosus). By the middle of 

 July many plum orchards throughout the Niagara district were quite heavily 

 infested with this mite, but the outbreak did not increase in severity to the 

 degree we at first anticipated. 



At Vineland the mite was easily controlled by spraying with wettable 

 sulphur or lime sulphur. 



Grape and Small Fruit Insects 



The Rose Chafer (Macrodactylus subspinosus) . This insect has seldom, 

 if ever, been more prevalent than it was this year. Severe outbreaks occurred 

 in most of the sandy sections of southwestern Ontario. Grapes, fruit trees, 

 ornamentals, etc., were attacked and seriously injured. It is worth while 

 recording that at Fonthill, according to a correspondent, a brood of ducklings 

 died as a result of eating the beetles. 



It is of interest to note that Mr. Hall's investigations at Fenwick have 

 furnished us with satisfactory evidence that the chafer only breeds to a very 

 slight extent in clover sod. Along with the other control measures, it would 

 therefore seem to be advisable to recommend the substitution of clovers for 

 grasses in chafer-infested districts. 



It is highly probable that serious outbreaks of the rose chafer will occur 

 again next year, judging by the immense numbers of grubs which were found 

 in sandy soils this fall at Fenwick, Dixie and Simcoe. In this connection we 

 might mention that the densest rose chafer grub population we have on record, 

 namely, 1,052 larvae per square yard, was found at Dixie in the Hydro-Electric 

 right-of-way. 



Grape Leaf Hoppers (Erythroneura comes and E. tricincta). Leaf hoppers 

 were again present in large numbers in Niagara vineyards. On the whole, this 

 year's outbreak was not so severe as that of 1922, but a larger area was affected, 

 viz., from the Niagara River to Hamilton. 



The Grape Berry Moth {Polychrosis viteana). During the past two 

 years the grape crop in a large vineyard near St. Catharines has been seriously 

 damaged by this pest. This season a very considerable percentage of the fruit 

 was infested — in many of the rows practically 100 per cent, of the bunches. 



The berry moth occurs in all parts of the Niagara peninsula, but it is very 

 rarely sufficiently numerous to cause any appreciable loss. As exposed pupae 

 of P. viteana are said to succumb quite readily to low temperatures, the Ontario 

 winter most probably accounts for our comparative immunity from injury. 



The Grape Blossom Midge (Contarinia Johns oni). What we take to be 

 this species destroyed a considerable percentage of the blossom buds in a vine- 

 yard near Fruitland. The affected buds, according to the grower, were swollen 

 and watery in appearance, and when opened were found to contain maggots. 

 The crop in this vineyard has been poor for several years back, and most of the 

 bunches have been thin and ragged. 



Colas pis flavida. This leaf beetle was commonly observed feeding on grape 

 foliage in the Niagara district, but only in a few cases did it cause sufficient 

 injury to attract the attention of the growers. 



The Red Spider {Tetranychus telarius). Favoured by exceptionally dry 

 weather, this pest appeared in outbreak form in the Niagara and several other 

 districts of southwestern Ontario. During July the mite was present in extra- 

 ordinary numbers on bush fruits and, as a result of its feeding activities, the 



