1923 ENTOMOLOGICAL SOCIETY. 37 



these injuries had in some cases died out and in others become diseased, so 

 that the stalks readily broke with very little strain. Eggs were found in some 

 of the punctures, but as usual no larvae were present. 



Corn Ear Worm (Heliothis obsoleta). The almost total disappearance of 

 this insect in 1922, after the remarkable outbreak in 1921, was very interesting. 

 Only about half-a-dozen larvae in all were seen by the writers this summer. 

 Experiments with larvae in the fall of 1921 and the great scarcity of the insect 

 this year tend to confirm the theory that the insect does not winter in Ontario, 

 or if so, only to a very slight extent. 



European Corn Borer (Pyrausta nubilalis). Discussed elsewhere in this 

 report. 



Spotted Cutworm {Agrotis c. nigrum). This cutworm was much more 

 numerous than usual, and during the latter half of July in several localities, 

 especially in Norfolk, Lambton, Peel and Lennox and Addington counties, there 

 were outbreaks of considerable importance. The newspapers erroneously 

 referred to these as "Army Worm Outbreaks." The outbreaks were not unex- 

 pected, because in Norfolk on April 26th the senior writer saw fields in which 

 the early brood of this same cutworm was abundant. At this date some of the 

 larvae were almost full-grown and others only half-grown, the average being 

 about one inch long. 



Potato Insects. The Potato Leaf Hopper (Empoasca mali) was perhaps 

 the most important potato pest in Southern Ontario. Flea Beetles {Epitrix 

 cucumeris) were very numerous, in some localities almost destroying potato 

 leaves and injuring considerably leaves of tomatoes. The Colorado Potato 

 Beetle {Leptinotarsa decemlineata) was not of its usual importance. 



Miscellaneous Insects 



Tarnished Plant Bug (Lygns pratensis). This pest, although less trouble- 

 some than usual on asters, was again injurious to chrysanthemums in some 

 greenhouses. 



The most effective method of preventing plant bug injury in greenhouses 

 is to screen the ventilators and doors with wire cloth. This past summer the 

 Dale Estate people at Brampton screened one of their chrysanthemum houses 

 and in reference to the results secured from this the Assistant General Manager 

 wrote under date of October 12th as follows: 



"There seems to be little question that the screening of the ventilators has 

 been very beneficial. In the house where this was carried out the tarnished 

 plant bug has been practically eliminated, while in the other houses the bugs 

 have been as bad this year as ever. Further, we have noticed no detrimental 

 effect in the matter of ventilation." 



Coiled Rose Worm (Emphyctus cinciipes). There was an outbreak of 

 this species in two large greenhouses near Grimsby. In both houses the larvae 

 were most abundant on the variety Premier. The slugs were easily destroyed 

 by an application of arsenate of lead. 



Grasshoppers. In Manitoulin Island there was the most extensive and 

 severe outbreak of grasshoppers which the senior writer has seen in Ontario. 

 The chief species involved was the Roadside Grasshopper (Camnula pellucida). 

 Almost every farm throughout the whole length of the island, over 100 miles, 

 was more or less infested. So numerous were the nymphs in the middle of June,, 

 when the writer visited the district, that there seemed no doubt that, if not com- 

 bated, they would totally destroy the grain crop and also much of the hay and 

 pasture. 



