373 



turning yellow before beginning to feed on them, and can then be found 

 in enormous numbers infesting wheat and barley stacJcs awaiting 

 threshing. When the attack is too bad for the crop to be saved, barley 

 especially is often cut just before the ear hardens, and stacked in small 

 heaps with the ears inwards to complete ripening ; grain so treated is, 

 however, of bad colour and shrivelled. D. albifrons is not migratory 

 and is rather local in occurrence, breeding over scattered areas among 

 the crops attacked. It is not a gregarious species, and therefore 

 poison baits are the most promising remedial measure. Schistocerca 

 peregrina (yellow migratory locust) probably originates in the Nejd 

 desert, which would make preventive treatment very difficult, but it 

 also breeds to a large extent in the vicinity of cultivated areas. The 

 migratory swarms appear before the insects are quite mature and 

 while the corn is still green, and frequently devastate whole fields in 

 one night. In the thinly populated districts there is not much hope of 

 combating migratory swarms, and remedial measures must be directed 

 to the destruction of the original hatching swarms in the spring, 

 while they are still in the hopper stage. 



Eelworms are distributed throughout the wheat-growing areas, and 

 the minute red wheat thrips causes sKght damage. Stem maggots 

 and leaf-miners occur in both barley and wheat ^vithout causing serious 

 losses. 



Gibson (A.). Boring Caterpillars affecting Corn and other Crops 

 and which are liable to be mistaken for the European Corn Borer. 



— Canada Dept. Agric, Entom. Branch, Ottawa, Circular 14, 

 9th April 1920, 14 pp., 6 figs. ["Received 5th July 1920.] 



As a result of the efforts made to prevent the introduction and 

 establishment in Canada of the European coin borer, Pgrausta nuhilalis, 

 and the pubHcity given to it, numerous caterpillars have been received 

 that have been mistaken for it. This circular has been prepared 

 in view of the fact that a number of these are also of economic import- 

 ance and to enable the various sjjecies that may be found to be dis- 

 tinguished. As P. nuhilalis closely resembles its nearest aUies and 

 also other borers in the younger stages, it is urged that the presence 

 of any borer found in plants, particularly maize, should be at once 

 reported and specimens sent to the nearest ofiicial entomologist. 

 Besides P. nuhilalis, which has not yet been found in Canada, and the 

 American P. ainslei and P. penitalis, a number of Canadian caterpillars 

 are described. The burdock borer, Papaipema cataphracta, occurs 

 commonly on burdock in Eastern Canada, and also attacks a number of 

 garden plants. The stalk borer, Papaipema nehris (nitela), in some 

 years seriously abundant in the northern States, has not been 

 responsible for important losses in Canada ; it attacks maize and 

 garden plants. The potato-stem borer, Gortgna micacea, is a pest of 

 some importance, particularly in New Brunswick and Nova Scotia, 

 though so far its attacks are practically confined to gardens. A 

 western corn borer, Helotropha reniformis atra, has been reported in con- 

 siderable numbers attaclcing maize in Manitoba ; and two larvae of a 

 new eastern corn borer, Apameanictitans americana, have been taken in 

 maize in Nova Scotia. The corn earworm, Heliothis ohsoleta, was more 

 than usually abimdant in Manitoba, Ontario and Quebec in 1919, 



