139 



Whitehouse (F. C). Entomological Report for 1920. — Ann. 

 Kept. Dept. Agric. Alberta, 1920, Edmonton, 1921, pp. 191-193. 

 [Received 14th January 1922.] 



Alberta experienced a very severe outbreak of grasshoppers in 1920, 

 Camnula pellncida, Scud., and Melanoplus atlantis, Riley, being 

 responsible for 90 per cent, of the damage. M. bivittatus. Say, 

 M. packardi, Scud., and Dissosteira Carolina, L., were also unusually 

 abundant. Cantharid and Bombyliid larvae feeding on the eggs 

 were fairly numerous in the extreme south, but further north no 

 enemies were found. 



Euxoa ochrogaster, Gn., was rarely present in destructive numbers, 

 probably owing to heavy parasitism in 1919 by the Hymenopteron, 

 A mblytelcs siitiiralis, and Tachinids. Grain crops were severely damaged 

 b}^ Porosagrotis orthogonia, Morr. Euxoa tristicula was taken in 

 numbers in the autumn from summer fallow, but over 33 per cent, of 

 the hibernating larvae were killed in the spring by the Chalcid, 

 Berecyntus bakeri. How., of which an average of 824 adults were bred 

 from every parasitised larva. A most widespread outbreak of 

 Loxostege sticticalis, L., occurred. In early June the adult moths were 

 vQxy abundant, and eggs were frequently found on Chenopodium 

 album. In the middle of July larvae of the first generation appeared 

 in unprecedented numbers. The outbreak, however, was, on the whole, 

 beneficial, as many fields contained more weeds than wheat, with, 

 insufficient moisture to develop this multiple crop. The webworms 

 devoured the weeds, scarcely touching the crops. The second genera- 

 tion of moths exceeded anything previously experienced. Rains 

 in July caused a growth of weeds on which many eggs were deposited, 

 but a subsequent drought dried them up. Larvae of CepJms occi- 

 dentalis, R. & M., were recorded for the first time injuring mature 

 wheat stems. 



Other pests included : — Peranabrus scabricollis, Thom. (Coulee 

 cricket), Gryllus pennsylvanicus, Burm., Pteronus ribesii, Scop., 

 Plutella maculipennis, Curt., and Leptinotarsa decemlineata. Say, 

 which was abundant on wild tomatos, but not exceptionally numerous 

 on potatoes. The Noctuid, Rhynchagrotis placida, Grote, was bred 

 from larvae collected on poplars. 



TiLLYARD (R. J.). The Hawthorn Hedge Menace.— Reprint from 

 Nelson [N.Z.] Evening Mail, 31st December 1920 & 4th cS: 5th 

 January 1921, 7 pp. [Received 16th January 1922.] 



Hedges formed of hawthorn [Crataegus] are a very serious menace in 

 New Zealand, because this plant is the intermediate host of fire blight 

 [Bacillus arnylovorus], and is also the food-plant of many noxious 

 insect pests. The life-history and habits of various pests of 

 orchard trees are recorded, and in each case the remedial measures 

 adopted would be sufficient to control them if the hawthorn, which 

 cannot be easily sprayed with arsenicals, were not an alternative 

 food-plant. The New Zealand pests given as examples include : 

 the pear tree sawfly [Eriocampoides limacina], codling moth [Cydia 

 pomonella], oyster-shell scale [Lepidosaphes ulmi], San Jose scale 

 [Aspidiotus perniciosus], and the small yellow leaf -hopper. 



The author advocates that all hawthorn hedges should be chpped to 

 a height of 4 ft., as this would prevent them from flowering and thus 



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